ORCID Profile
0000-0002-7678-7482
Current Organisation
Curtin University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Physical Chemistry (Incl. Structural) | Electrochemistry | Colloid and Surface Chemistry | Electroanalytical Chemistry | Nanoscale Characterisation | Analytical Chemistry | Sensor Technology (Chemical aspects) | Microelectronics and Integrated Circuits | Non-automotive Combustion and Fuel Engineering (incl. Alternative/Renewable Fuels) | Electrical and Electronic Engineering | Structural Chemistry and Spectroscopy | Biochemistry and Cell Biology not elsewhere classified | Nanomaterials | Plant Cell and Molecular Biology | Nanotechnology | Compound Semiconductors | Microelectromechanical Systems (MEMS) | Surfaces and Structural Properties of Condensed Matter
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Chemical Sciences | Expanding Knowledge in the Biological Sciences | Hydrogen Storage | Production of Biofuels (Biomass) | Expanding Knowledge in Technology | Hydrogen-based Energy Systems (incl. Internal Hydrogen Combustion Engines) | Industrial Instruments | Scientific Instruments | Integrated Circuits and Devices | Integrated Systems |
Related Links
Publications
A lithium iron phosphate reference electrode for ionic liquid electrolytes
Publisher: Elsevier BV
Date: 08-2018
Synthesis, Photophysical and Electrochemical Investigation of Dinuclear Tetrazolato-Bridged Rhenium Complexes
Publisher: American Chemical Society (ACS)
Date: 29-10-2012
DOI: 10.1021/OM300870A
Void-assisted ion-paired proton transfer at water-ionic liquid interfaces
Publisher: Wiley
Date: 22-10-2016
Electroreduction of Chlorine Gas at Platinum Electrodes in Several Room Temperature Ionic Liquids: Evidence of Strong Adsorption on the Electrode Surface Revealed by Unusual Voltammetry in Which Curre
Publisher: American Chemical Society (ACS)
Date: 13-11-2008
DOI: 10.1021/JP8082437
Electrochemical Behavior of Chlorine on Platinum Microdisk and Screen-Printed Electrodes in a Room Temperature Ionic Liquid
Publisher: American Chemical Society (ACS)
Date: 06-10-2015
Metal organic frameworks with carbon black for the enhanced electrochemical detection of 2,4,6-trinitrotoluene
Publisher: Elsevier BV
Date: 12-2023
Electrochemical Oxidation of Nitrite and the Oxidation and Reduction of NO2 in the Room Temperature Ionic Liquid [C2mim][NTf2]
Publisher: American Chemical Society (ACS)
Date: 16-06-2007
DOI: 10.1021/JP0728104
Abstract: The electrochemical oxidation of potassium nitrite has been studied in the room temperature ionic liquid (RTIL) [C2mim][NTf2] by cyclic voltammetry at platinum electrodes. A chemically irreversible oxidation peak was observed, and a solubility of 7.5(+/-0.5) mM and diffusion coefficient of 2.0(+/-0.2)x10(-11) m2 s(-1) were calculated from potential step chrono erometry on the microdisk electrode. A second, and sometimes third, oxidation peak was also observed when the anodic limit was extended, and these were provisionally assigned to the oxidation of nitrogen dioxide (NO2) and nitrate (NO3-), respectively. The electrochemical oxidation of nitrogen dioxide gas (NO2) was also studied by cyclic voltammetry in [C2mim][NTf2] on Pt electrodes of various size, giving a solubility of ca. 51(+/-0.2) mM and diffusion coefficient of 1.6(+/-0.05)x10(-10) m2 s(-1) (at 25 degrees C). It is likely that NO2 exists predominantly as its dimer, N2O4, at room temperature. The oxidation mechanism follows a CE process, which involves the initial dissociation of the dimer to the monomer, followed by a one-electron oxidation. A second, larger oxidation peak was observed at more positive potentials and is thought to be the direct oxidation of N2O4. In addition to understanding the mechanisms of NO2- and NO2 oxidations, this work has implications in the electrochemical detection of nitrite ions and of NO2 gas in RTIL media, the latter which may be of particular use in gas sensing.
Phase-Controllable Cobalt Phosphides Induced through Hydrogel for Higher Lithium Storages
Publisher: American Chemical Society (ACS)
Date: 23-04-2020
Emerging Ionic Polymers for CO
Publisher: CSIRO Publishing
Date: 25-10-2021
DOI: 10.1071/CH21182
Abstract: In this mini review, we highlight some key work from the last 2 years where ionic polymers have been used as a catalyst to convert CO2 into cyclic carbonates. Emerging ionic polymers reported for this catalytic application include materials such as poly(ionic liquid)s (PILs), ionic porous organic polymers (iPOPs) or ionic covalent organic frameworks (iCOFs) among others. All these organic materials share in common the ionic moiety cations such as imidazolium, pyridinium, viologen, ammonium, phosphonium, and guanidinium, and anions such as halides, [BF4]–, [PF6]–, and [Tf2N]–. The mechanistic aspects and efficiency of the CO2 conversion reaction and the polymer design including functional groups and porosity are discussed in detail. This review should provide valuable information for researchers to design new polymers for important catalysis applications.
An Electrochemical Study of the Oxidation of Hydrogen at Platinum Electrodes in Several Room Temperature Ionic Liquids
Publisher: American Chemical Society (ACS)
Date: 07-02-2007
DOI: 10.1021/JP067236V
Abstract: The electrochemical oxidation of dissolved hydrogen gas has been studied in a range of room-temperature ionic liquids (RTILs), namely [C(2)mim][NTf(2)], [C(4)mim][NTf(2)], [N(6,2,2,2)][NTf(2)], [P(14,6,6,6)][NTf(2)], [C(4)mpyrr][NTf(2)], [C(4)mim][BF(4)], [C(4)mim][PF(6)], [C(4)mim][OTf], and [C(6)mim]Cl on a platinum microdisk electrode of diameter 10 microm. In all cases, except [C(6)mim]Cl, a broad quasi-electrochemically reversible oxidation peak between 0.3 to 1.3 V vs Ag was seen prior to electrode activation ([C(6)mim]Cl showed an almost irreversible wave). When the electrode was pre-anodized ("activated") at 2.0 V vs Ag for 1 min, the peak separations became smaller, and the peak shape became more electrochemically reversible. It is thought that the electrogenerated protons chemically combine with the anions (A-) of the RTIL. The appearance and position of the reverse (reduction) peak on the voltammograms is thought to depend on three factors: (1) the stability of the protonated anion, HA, (2) the position of equilibrium of the protonation reaction HA H+ + A- , and (3) any follow-up chemistry, e.g., dissociation or reaction of the protonated anion, HA. This is discussed for the five different anions studied. The reduction of HNTf(2) was also studied in two [NTf(2)]- -based RTILs and was compared to the oxidation waves from hydrogen. The results have implications for the defining of pKa in RTIL media, for the development of suitable reference electrodes for use in RTILs, and in the possible erometric sensing of H2 gas.
Sensors for Highly Toxic Gases: Methylamine and Hydrogen Chloride Detection at Low Concentrations in an Ionic Liquid on Pt Screen Printed Electrodes
Publisher: MDPI AG
Date: 22-10-2015
DOI: 10.3390/S151026866
Electrochemical Behaviour of Organic Explosive Compounds in Ionic Liquids: Towards Discriminate Electrochemical Sensing
Publisher: Wiley
Date: 15-12-2022
Abstract: The electrochemical reduction of four organic explosive compounds, 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane (HMX), 1,3,5‐trinitro‐1,3,5‐triazinane (RDX), pentaerythritol tetranitrate (PETN) and 2,4,6‐trinitrophenylmethylnitramine (tetryl), is studied in eight room temperature ionic liquids (RTILs). In all RTILs, the reduction peaks were highly complicated, but much better resolved than in previous studies in conventional solvents. HMX typically showed broad overlapping peaks in RTILs with distinctly different voltammetric wave shapes. The voltammetry of RDX also varied dramatically, ranging from one to four reductive peaks with broad features. PETN showed one large reduction peak owing to the overlapping reduction processes for all the nitro‐ groups. Tetryl produced the most complex voltammetry with the largest number of cathodic peaks, likely due to the structure that contains both nitramine and nitroaromatic groups. For all explosives, an electrogenerated product was oxidized on the reverse scan. The reduction potentials and voltammetric wave shapes were found to vary significantly in the different RTILs, allowing the possibility to ‘fingerprint’ the different explosives using their distinct signatures, suggesting that discriminative sensing may be possible by careful tuning of the RTIL structure. Exploring the electrochemical behaviour of these explosives is a first step towards utilising RTILs as favourable solvents for the electrochemical detection of such compounds.
Synchrotron Radiation/Fourier Transform-Infrared Microspectroscopy Study of Undesirable Water Inclusions in Solid-Contact Polymeric Ion-Selective Electrodes
Publisher: American Chemical Society (ACS)
Date: 17-06-2010
DOI: 10.1021/AC101009N
Abstract: This paper reports on three-dimensional synchrotron radiation/Fourier transform-infrared microspectroscopy (SR/FT-IRM) imaging studies of water inclusions at the buried interface of solid-contact-ion-selective electrodes (SC-ISEs). It is our intention to describe a nondestructive method that may be used in surface studies of the buried interfaces of materials, especially multilayers of polymers. Herein, we demonstrate the power of SR/FT-IRM for studying water inclusions at the buried interfaces of SC-ISEs. A poly(methyl methacrylate)-poly(decyl methacyrlate) [PMMA-PDMA] copolymer revealed the presence of micrometer sized inclusions of water at the gold/membrane interface, while a coupling of a hydrophobic solid contact of poly(3-octylthiophene 2,5-diyl) (POT) prevented the accumulation of water at the buried interface. A similar study with a poly (3,4-ethylenedioxythiophene) oly (styrenesulfonate) [PEDOT/PSS] solid contact also revealed an absence of distinct micrometer-sized pools of water however, there were signs of absorption of water accompanied by swelling of the PEDOT/PSS underlayer, and these membrane zones are enriched with respect to water.
Effect of water on the electrochemical window and potential limits of room-temperature ionic liquids
Publisher: American Chemical Society (ACS)
Date: 07-11-2008
DOI: 10.1021/JE800678E
Tuning the Catalytic Activity of Bifunctional Cobalt Boride Nanoflakes for Overall Water Splitting over a Wide pH Range
Publisher: The Electrochemical Society
Date: 09-2022
Abstract: The world is in the process of transitioning towards a more sustainable energy future, with green hydrogen considered an attractive energy vector that can replace fossil fuel consumption, meeting global energy demands. To date, the most advanced method to produce green hydrogen is through water electrolysis using the residual supply of renewable energy. The current state-of-the-art catalysts used in electrolyzers are platinum-based metals and ruthenium/iridium oxides. The scarceness of these elements, combined with their high price, make these catalysts not economically viable for largescale production of hydrogen through water electrolysis. This study presents cobalt boride nanoflakes as materials to be used in both the anode and the cathode of an electrolyzer for electrochemical water splitting over a wide pH range. The cobalt boride nanoflakes were synthesized by the chemical reduction of CoCl 2 using NaBH 4 at three different concentrations to obtain CoB and Co 2 B nanoflakes. CoB nanoflakes exhibited both a higher specific surface area and greatest disparity in charge between B and Co, in comparison to Co 2 B. It was demonstrated that by tuning the properties of the cobalt boride nanoflakes, higher catalytic activities for both the hydrogen and oxygen evolution reaction can be achieved, showing good overall stability.
Oxidation of Several p-Phenylenediamines in Room Temperature Ionic Liquids: Estimation of Transport and Electrode Kinetic Parameters
Publisher: American Chemical Society (ACS)
Date: 05-04-2008
DOI: 10.1021/JP800235T
Chronoamperometric response at nanoscale liquid-liquid interface arrays
Publisher: Elsevier BV
Date: 07-2013
Detection of 2,4,6-Trinitrotoluene Using a Miniaturized, Disposable Electrochemical Sensor with an Ionic Liquid Gel-Polymer Electrolyte Film
Publisher: American Chemical Society (ACS)
Date: 04-04-2017
DOI: 10.1021/ACS.ANALCHEM.7B00679
Abstract: A new electrochemical method to detect and quantify the explosive compound 2,4,6-trinitrotoluene (TNT) in aqueous solutions is demonstrated. A disposable thin-film electrode modified with a droplet of a gel-polymer electrolyte (GPE) was immersed directly into s les of TNT at concentrations of 1-10 μg/mL. The GPE contained the hydrophobic room-temperature ionic liquid (RTIL) trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide ([P
Comparison of Voltammetric Techniques for Ammonia Sensing in Ionic Liquids
Publisher: Wiley
Date: 07-11-2017
Built-in anionic equilibrium for atom-economic recycling of spent lithium-ion batteries
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3EE00571B
Abstract: Built-in anionic equilibrium strategy is proposed to recover lithium from spent LiFePO 4 cathodes with high atom economy.
Electrooxidation of the Iodides [C4mim]I, LiI, NaI, KI, RbI, and CsI in the Room Temperature Ionic Liquid [C4mim][NTf2]
Publisher: American Chemical Society (ACS)
Date: 25-03-2008
DOI: 10.1021/JP800145K
Screen-Printed Graphite Electrodes as Low-Cost Devices for Oxygen Gas Detection in Room-Temperature Ionic Liquids
Publisher: MDPI AG
Date: 26-11-2017
DOI: 10.3390/S17122734
Mechanical polishing as an improved surface treatment for platinum screen-printed electrodes
Publisher: Elsevier BV
Date: 07-2016
A methodology to detect explosive residues using a gelled ionic liquid based field-deployable electrochemical device
Publisher: Elsevier BV
Date: 09-2020
Diverse morphologies of zinc oxide nanoparticles and their electrocatalytic performance in hydrogen production
Publisher: Elsevier BV
Date: 05-2021
Electrochemical Reduction of Benzoic Acid and Substituted Benzoic Acids in Some Room Temperature Ionic Liquids
Publisher: American Chemical Society (ACS)
Date: 25-07-2008
DOI: 10.1021/JP802996Q
Electrochemical Ammonia Gas Sensing in Nonaqueous Systems: A Comparison of Propylene Carbonate with Room Temperature Ionic Liquids
Publisher: Wiley
Date: 24-10-2007
Nanostructure of Locally Concentrated Ionic Liquids in the Bulk and at Graphite and Gold Electrodes
Publisher: American Chemical Society (ACS)
Date: 26-10-2023
Zinc Oxide Nanoparticles as Antifouling Materials for the Electrochemical Detection of Methylparaben
Publisher: Wiley
Date: 04-01-2021
Macroporous platinum electrodes for hydrogen oxidation in ionic liquids
Publisher: Elsevier BV
Date: 2018
Coulometry on the Voltammetric Timescale: Microdisk Potential-Step Chronoamperometry in Aprotic Solvents Reliably Measures the Number of Electrons Transferred in an Electrode Process Simultaneously with the Diffusion Coefficients of the Electroactive Species
Publisher: Wiley
Date: 2007
Electrochemical reduction of nitrobenzene and 4-nitrophenol in the room temperature ionic liquid [C4dmim][N(Tf)2]
Publisher: Elsevier BV
Date: 11-2006
Electrochemical Characterization of an Oleyl-coated Magnetite Nanoparticle-Modified Electrode
Publisher: Wiley
Date: 19-05-2014
Thin films of poly(vinylidene fluoride-co-hexafluoropropylene)-ionic liquid mixtures as amperometric gas sensing materials for oxygen and ammonia.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9AN02153A
Abstract: Gas sensors are important devices used to monitor the type and amount of gas present. Amperometric gas sensors - based on measuring the current upon an applied potential - have been progressing towards miniaturised designs that are smaller, lower cost, faster responding and more robust compared to commercially available sensors. In this work, a planar thin-film electrode device is employed for gas sensing with a thin layer of gel polymer electrolyte (GPE). The GPE consists of a room temperature ionic liquid (RTIL, with two different imidazolium cations and the tetrafluoroborate [BF4]- anion) mixed with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). The polymer acts as a scaffold, with the RTIL ions able to flow within the porous percolated channels, resulting in a highly robust gel with high conductivity. The chemical nature of the polymer allows thin-films (ca. 6 μm) to be evenly dropcast onto planar electrode devices, using minimal amounts of material. Remarkably, no significant effect of resistance was observed in the voltammetric response with such thin films. Oxygen (O2) and ammonia (NH3) gases were detected in the concentration ranges 1-20% O2 and 1-10 ppm NH3 in the two GPEs using both linear sweep voltammetry (LSV) and long-term chrono erometry (LTCA). LTCA was the preferred detection method for both gases due to the steady-state current response compared to the sloping current response from LSV. The thin nature of the film gave fast response times for both gases - less than 10 seconds for O2 and ca. 40 seconds for NH3 - easily rivaling the commercially available porous electrode designs and allowing for continuous monitoring of gas concentrations. These materials appear to be highly promising candidates as gas detection electrolytes in miniaturised devices, with accurate and fast responses in both the cathodic and anodic potential regions.
Cation effect on the electrochemical reduction of polyoxometalates in room temperature ionic liquids
Publisher: CSIRO Publishing
Date: 22-11-2022
DOI: 10.1071/CH22140
Abstract: Polyoxometalates (POMs) are compounds that undergo multiple successive one-electron redox transitions, making them convenient model reactants to study ion solvation effects. Room temperature ionic liquids (RTILs) are solvents made entirely of ions, and are expected to have interactions with the highly negatively charged POM reduction products. In this work, 12 RTILs with a range of different anions ([FSI]−=bis(fluorosulfonyl)imide, [TFSI]−=bis(trifluoromethylsulfonyl)imide, [BETI]−=bis(pentafluoroethylsulfonyl)imide, [BF4]−, [PF6]−) and cations (imidazolium, pyrrolidinium, sulfonium, ammonium, phosphonium) were employed as solvents to study the kinetics and thermodynamics of [S2W18O62]4− reduction, to shed light on solvation effects and ion-pairing effects caused by different RTIL structures. Up to six reversible reduction processes (producing highly negatively charged [S2W18O62]10−) were observed. For the RTILs that showed multiple processes, a clear trend in both the thermodynamics (inferred from the reduction peak potentials) and kinetics (inferred from the peak-to-peak separation) was observed, in the order: imidazolium sulfonium ≈ ammonium pyrrolidinium phosphonium, supporting strong interactions of the negatively charged POM reduction products with the cation. Two related POMs, [P2W18O62]6− and [PW12O40]3−, were also studied in the optimum RTIL found for [S2W18O62]4− ([C2mim][FSI]=1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide), revealing fast kinetics and asymmetric peaks for [PW12O40]3−. This work demonstrates the importance of understanding the solvation effects of RTIL ions for highly charged electrogenerated products, allowing tuning of the RTIL structure to achieve the optimum kinetics and thermodynamics for an electrochemical process.
Ionic Liquid-Based Microchannels for Highly Sensitive and Fast Amperometric Detection of Toxic Gases
Publisher: Wiley
Date: 13-11-2018
Oxygen reduction voltammetry on platinum macrodisk and screen-printed electrodes in ionic liquids: Reaction of the electrogenerated superoxide species with compounds used in the paste of Pt screen-printed electrodes?
Publisher: Elsevier BV
Date: 02-2097
Ionic liquid gel polymer electrolytes for flexible supercapacitors: Challenges and prospects
Publisher: Elsevier BV
Date: 10-2022
Detection of sub-ppm Concentrations of Ammonia in an Ionic Liquid: Enhanced Current Density Using “Filled” Recessed Microarrays
Publisher: American Chemical Society (ACS)
Date: 07-12-2016
DOI: 10.1021/ACS.ANALCHEM.6B03824
Abstract: The voltammetric detection of less than 1 ppm of ammonia gas in the room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C
Experimental Evidence of Long-Lived Electric Fields of Ionic Liquid Bilayers
Publisher: American Chemical Society (ACS)
Date: 16-10-2021
DOI: 10.1021/JACS.1C06385
Abstract: Herein we demonstrate that ionic liquids can form long-lived double layers, generating electric fields detectable by straightforward open circuit potential (OCP) measurements. In imidazolium-based ionic liquids an external negative voltage pulse leads to an exceedingly stable near-surface dipolar layer, whose field manifests as long-lived (∼1-100 h) discrete plateaus in OCP versus time traces. These plateaus occur within an ionic liquid-specific and sharp potential window, defining a simple experimental method to probe the onset of interfacial ordering phenomena, such as overscreening and crowding. Molecular dynamics modeling reveals that the OCP arises from the alignment of the in idual ion dipoles to the external electric field pulse, with the magnitude of the resulting OCP correlating with the product of the projected dipole moment of the cation and the ratio between the cation diffusion coefficient and its volume. Our findings also reveal that a stable overscreened structure is more likely to form if the interface is first forced through crowding, possibly accounting for the scattered literature data on relaxation kinetics of near-surface structures in ionic liquids.
One-step assembly of Re(i) tricarbonyl 2-pyridyltetrazolato metallacalix[3]arene with aqua emission and reversible three-electron oxidation
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3DT50988E
Abstract: The reaction of 2-pyridyltetrazolate with [Re(CO)5X] (X = Cl, Br) yielded the formation of an unexpected cyclic metallacalix[3]arene, as revealed by X-ray structural studies, characterised by aqua emission and reversible three-electron oxidation.
Molten metal closo-borate solvates
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CC00187E
Abstract: Li 2 B 12 H 12 is reported in the molten state for the first time, which enables a range of new research opportunities.
Mechanistic Studies of the Electro-oxidation Pathway of Ammonia in Several Room-Temperature Ionic Liquids
Publisher: American Chemical Society (ACS)
Date: 06-2007
DOI: 10.1021/JP0715732
Assessing ion-exchange properties and purity of lipophilic electrolytes by potentiometry and spectrophotometry
Publisher: Elsevier BV
Date: 2010
The electrochemical oxidation of hydrogen at activated platinum electrodes in room temperature ionic liquids as solvents
Publisher: Elsevier BV
Date: 07-2008
Electrochemical Synthesis of Highly Ordered Porous Al Scaffolds Melt-Infiltrated with LiBH4for Hydrogen Storage
Publisher: The Electrochemical Society
Date: 2018
DOI: 10.1149/2.0481802JES
Correction to “Electrical Double Layer Structure in Ionic Liquids and Its Importance for Supercapacitor, Battery, Sensing, and Lubrication Applications”
Publisher: American Chemical Society (ACS)
Date: 10-02-2023
Recent advances in the use of ionic liquids for electrochemical sensing
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1AN15699C
Abstract: Ionic Liquids are salts that are liquid at (or just above) room temperature. They possess several advantageous properties (e.g. high intrinsic conductivity, wide electrochemical windows, low volatility, high thermal stability and good solvating ability), which make them ideal as non-volatile electrolytes in electrochemical sensors. This mini-review article describes the recent uses of ionic liquids in electrochemical sensing applications (covering the last 3 years) in the context of voltammetric sensing at solid/liquid, liquid/liquid interfaces and carbon paste electrodes, as well as their use in gas sensing, ion-selective electrodes, and for detecting biological molecules, explosives and chemical warfare agents. A comment on the future direction and challenges in this field is also presented.
Effect of Humidity and Impurities on the Electrochemical Window of Ionic Liquids and Its Implications for Electroanalysis
Publisher: American Chemical Society (ACS)
Date: 21-08-2020
Preparation of platinum-based 'cauliflower microarrays’ for enhanced ammonia gas sensing
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.ACA.2018.09.055
Abstract: In erometric gas sensors, the flux of gas to electrode surfaces determines the analytical response and detection limit. For trace concentration detection, the resulting low current prevents the miniaturisation of such sensors. Therefore, in this study, we have developed repeating arrays of nanostructures which maximise flux towards their surface. Unique platinum 3D cauliflower-shaped deposits with in idual floret-shaped segments have been produced in a single step electrodeposition process. The confined walls of recessed microelectrode arrays (10 μm in diameter, 90 electrodes) are utilized to produce these structures with a high surface area. Distinct segments are observed, with the gaps corresponding to electrodes adjacent in the microarray thus the majority of the deposits face the primary diffusion zones. The sizes and shapes of the deposits are characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) and the largest structures are found to be 22 ± 1 μm in width and 7.9 ± 0.2 μm in height over the microhole. These modified electrodes are employed to detect ammonia using the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C
Dynamic and Static Quenching of Fluorescence by 1−4 nm Diameter Gold Monolayer-Protected Clusters
Publisher: American Chemical Society (ACS)
Date: 15-02-2006
DOI: 10.1021/JP057028N
Abstract: How the efficiency of molecular quenching by Au nanoparticles depends on nanoparticle size is reported for (a) dynamic (collisional) quenching of four different fluorophores by three Au nanoparticles having similar protective layers but differing core diameters (1.1, 1.6, and 2.0 nm) and (b) static quenching in the electrostatic association between [Ru(bpy)3]2+ and five tiopronin-protected Au nanoparticles having core diameters from 1.3 to 3.9 nm. The quenching constants systematically increase with core size. In (a), the dynamic constants scale with the molar absorbance coefficients of the nanoparticles, showing the essentially of the absorbance/emission spectral overlap, and the associated nanoparticle core density of electronic states, in energy-transfer quenching. In (b), the fluorescence of the Au nanoparticle itself was enhanced by energy transfer from the [Ru(bpy)3]2+ fluorophore.
Ionophore-Assisted Electrochemistry of Neutral Molecules: Oxidation of Hydrogen in an Ionic Liquid Electrolyte
Publisher: American Chemical Society (ACS)
Date: 22-10-2019
DOI: 10.26434/CHEMRXIV.7900943.V2
Abstract: The electrochemical properties of gas molecules are of great interest for both fundamental and applied research. In this study, we introduce a novel concept to systematically alter the electrochemical behavior and, in particular, the redox potential of neutral gas molecules. The concept is based on the use of an ion-binding agent, or ‘ionophore’, to bind and stabilize the ionic electrochemical reaction product. We demonstrate that the ionophore-assisted electrochemical oxidation of hydrogen in a room temperature ionic liquid electrolyte is shifted by almost 1 V towards more negative potentials in comparison to an ionophore-free electrolyte. The altered electrochemical response in the presence of the ionophore not only yields insights into the reaction mechanism but can be used also to determine the diffusion coefficient of the ionophore species. This ionophore-modulated electrochemistry of neutral gas molecules opens up new avenues for the development of highly selective electrochemical sensors.
Ionophore-Assisted Electrochemistry of Neutral Molecules: Oxidation of Hydrogen in an Ionic Liquid Electrolyte
Publisher: American Chemical Society (ACS)
Date: 27-03-2019
DOI: 10.26434/CHEMRXIV.7900943.V1
Abstract: The electrochemical properties of gas molecules are of high interest for both fundamental and applied research. In this study, we introduce a novel concept to systematically alter the electrochemical behavior and, in particular, the redox potential of neutral gas molecules. The concept is based on the use of an ionophore to bind and stabilize the ionic electrochemical reaction product. We demonstrate that the ionophore-assisted electrochemical oxidation of hydrogen in a room temperature ionic liquid electrolyte is shifted by almost 1 V towards more negative potentials in comparison to an ionophore-free electrolyte. The altered electrochemical response in the presence of the ionophore yields insights into the reaction mechanism and can be used to determine the diffusion coefficient of the ionophore species. The ionophore-modulated electrochemistry of neutral gas molecules opens new avenues for the development of selective electrochemical sensors with reduced cross-sensitivity.
Electrochemical Reduction of 2,4-Dinitrotoluene in Room Temperature Ionic Liquids: A Mechanistic Investigation
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/CH18315
Abstract: The reduction mechanism of 2,4-dinitrotoluene (DNT) has been studied in eight room temperature ionic liquids (RTILs) using cyclic voltammetry (CV), square wave voltammetry (SWV), chrono erometry, and digital simulation. Two distinctive peaks are observed in the voltammetry, corresponding to the stepwise reduction of the two nitro groups on the aromatic ring. Diffusion coefficients (D) and electron counts (n) were calculated from chrono erometric transients, revealing an electron count of one in most RTILs, and a linear relationship between D and the inverse of viscosity. Focusing on the first reduction only, the peak appears to be chemically reversible at low concentrations. However, as the concentration increases, the current of the reverse peak diminishes, suggesting that one or more chemical steps occur after the electrochemical step. The results from digital simulation of the CVs in one of the RTILs reveal that the most likely mechanism involves a deprotonation of the methyl group of a parent DNT molecule by the electrogenerated radical anion and/or a dimerisation of two electrogenerated radical anions. Elucidation of the reduction mechanism of DNT (and other explosives) is vital if electrochemical techniques are to be employed to detect these types of compounds in the field.
Effect of Ionic Liquid Structure on the Oxygen Reduction Reaction Under Humidified Conditions
Publisher: American Chemical Society (ACS)
Date: 05-04-2019
Potentiometric determination of coextraction constants of potassium salts in ion-selective electrodes utilizing a nitrobenzene liquid membrane phase
Publisher: Elsevier BV
Date: 12-2010
DOI: 10.1016/J.ACA.2010.10.012
Abstract: A theoretical treatment of potentiometric data is applied to calculate coextraction constants (K(IA)) for three potassium salts from water into a liquid nitrobenzene phase. The experiment involves treating nitrobenzene as a membrane and contacting it with two aqueous solutions of different ion activities. In the presence of either a cation or anion exchanger, the ratio of activities of ions in the two aqueous phases gives rise to a potential difference across the membrane that depends upon the nature and charge of the counter ion of the ion-exchanger in excess. Here, the cation exchanger was chosen to be potassium tetrakis(4-chlorophenyl)borate (KTpClPB) and the anion exchanger was tetradodecylammonium chloride (TDDACl). TDDACl was incrementally added to the nitrobenzene phase containing a fixed concentration of KTpClPB, and the corresponding emf was recorded as a function of concentration of TDDACl. The membrane changes from one with cation exchanger properties (excess KTpClPB) to one with anion exchanger properties (excess TDDACl). The potential difference and shape of the titration curve can be predicted by theory based on the phase boundary potential model. Log(K(IA)) values calculated for KCl, KNO(3) and KClO(4) in nitrobenzene were found as: -10.53 (± 0.09), -8.16 (± 0.05) and -5.63 (± 0.03) respectively, in accordance with the Hofmeister series of lipophilicity, and similar to those observed in PVC membranes containing other plasticizers. The method presented here offers the advantage over other methods to calculate K(IA), in that it is relatively experimentally simple without compromising the accuracy of the calculated coextraction constants. The ability to titrate directly into the liquid membrane phase affords a higher precision compared to the preparation of a series of PVC lasticizer membranes with different compositions.
Electroreduction of Sulfur Dioxide in Some Room-Temperature Ionic Liquids
Publisher: American Chemical Society (ACS)
Date: 13-02-2008
DOI: 10.1021/JP7109093
Ionic liquid/poly(ionic liquid) membranes as non-flowing, conductive materials for electrochemical gas sensing
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.ACA.2021.339414
Abstract: Ionic liquids (ILs) are highly promising, tuneable materials that have the potential to replace volatile electrolytes in erometric gas sensors in a 'membrane-free' sensor design. However, the drawback of removing the membrane is that the liquid ILs can readily leak or flow from the sensor device when moved/agitated in different orientations. A strategy to overcome the flowing nature of ILs is to mix them with polymers to stabilise them on the surface in the form of membranes. In this research, the room temperature ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C
Redox Properties of a Rhenium Tetrazolato Complex in Room Temperature Ionic Liquids: Assessing the Applicability of the Stokes–Einstein Equation for a Metal Complex in Ionic Liquids
Publisher: American Chemical Society (ACS)
Date: 26-03-2012
DOI: 10.1021/JP3007975
Formation of 3-Dimensional Gold, Copper and Palladium Microelectrode Arrays for Enhanced Electrochemical Sensing Applications
Publisher: MDPI AG
Date: 15-08-2019
DOI: 10.3390/NANO9081170
Abstract: Microelectrodes offer higher current density and lower ohmic drop due to increased radial diffusion. They are beneficial for electroanalytical applications, particularly for the detection of analytes at trace concentrations. Microelectrodes can be fabricated as arrays to improve the current response, but are presently only commercially available with gold or platinum electrode surfaces, thus limiting the sensing of analytes that are more electroactive on other surfaces. In this work, gold (Au), copper (Cu), and palladium (Pd) are electrodeposited at two different potentials into the recessed holes of commercial microelectrode arrays to produce 3-dimensional (3D) spiky, dendritic or coral-like structures. The rough fractal structures that are produced afford enhanced electroactive surface area and increased radial diffusion due to the 3D nature, which drastically improves the sensitivity. 2,4,6-trinitrotoluene (TNT), carbon dioxide gas (CO2), and hydrogen gas (H2) were chosen as model analytes in room temperature ionic liquid solvents, to demonstrate improvements in the sensitivity of the modified microelectrode arrays, and, in some cases (e.g., for CO2 and H2), enhancements in the electrocatalytic ability. With the deposition of different materials, we have demonstrated enhanced sensitivity and electrocatalytic behaviour towards the chosen analytes.
Electrical Double Layer Structure in Ionic Liquids and Its Importance for Supercapacitor, Battery, Sensing, and Lubrication Applications
Publisher: American Chemical Society (ACS)
Date: 21-06-2021
Ligand-Induced Structural, Photophysical, and Electrochemical Variations in Tricarbonyl Rhenium(I) Tetrazolato Complexes
Publisher: American Chemical Society (ACS)
Date: 17-06-2013
DOI: 10.1021/OM400356N
New innovations in ionic liquid–based miniaturised amperometric gas sensors
Publisher: Elsevier BV
Date: 06-2019
Using XPS to determine solute solubility in room temperature ionic liquids
Publisher: Royal Society of Chemistry (RSC)
Date: 2007
DOI: 10.1039/B700212B
Abstract: X-Ray Photoelectron Spectroscopy (XPS) was used to quantify the amount of bromide ions present in two s les of [C(4)mpyrr]Br dissolved in the room temperature ionic liquid (RTIL) [C(4)mpyrr][N(Tf)2]. One s le was of a known concentration (0.436 Br atom%) the other was a saturated solution. The results obtained from quantitative XPS analysis indicated that the saturated s le had a concentration, or solubility, of 0.90 Br atom% (746 mM) at 298 K, which was then independently confirmed by potential-step chrono erometry of the same solution.
Hydrogen-bonding 2D coordination polymer for enzyme-free electrochemical glucose sensing
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2CE00240J
Abstract: Regular detection of blood glucose levels is a critical indicator for effective diabetes management.
Electrochemical Kinetics of Ag|Ag+ and TMPD|TMPD+• in the Room-Temperature Ionic Liquid [C4mpyrr][NTf2]; toward Optimizing Reference Electrodes for Voltamme
Publisher: American Chemical Society (ACS)
Date: 28-08-2007
DOI: 10.1021/JP0737754
Mixing Ionic Liquids Affects the Kinetics and Thermodynamics of the Oxygen/Superoxide Redox Couple in the Context of Oxygen Sensing
Publisher: American Chemical Society (ACS)
Date: 26-09-2022
Electrodeposited Metal Organic Framework toward Excellent Hydrogen Sensing in an Ionic Liquid
Publisher: American Chemical Society (ACS)
Date: 08-04-2020
Electrochemical properties of a verdazyl radical in room temperature ionic liquids
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/CH19575
The electrochemical oxidation and reduction of nitrate ions in the room temperature ionic liquid [C2mim][NTf2]; the latter behaves as a ‘melt’ rather than an ‘organic solvent’
Publisher: Royal Society of Chemistry (RSC)
Date: 2007
DOI: 10.1039/B701097D
Behavior of Lysozyme at the Electrified Water/Room Temperature Ionic Liquid Interface
Publisher: Wiley
Date: 24-07-2012
Abstract: Between the phases: The globular protein lysozyme was adsorbed and desorbed under electrochemical conditions at the water/room temperature ionic liquid microinterface array the electrochemical desorption process provides a basis for protein detection at these interfaces.
Electrochemistry in Room Temperature Ionic Liquids: A Review and Some Possible Applications
Publisher: Walter de Gruyter GmbH
Date: 10-2006
DOI: 10.1524/ZPCH.2006.220.10.1247
Abstract: A review of electrochemistry in ionic liquids is presented, highlighting some particular ex les, with the aim to compare any similarities and differences observed in RTILs to that observed in conventional solvents. The presence of impurities such as halide and water on the electrochemical window and viscosity of RTILs is discussed. Some fundamental electrochemical studies relating to mass transport, heterogeneous electron transfer kinetics and double-layer capacitance are compared to similar studies in conventional solvents, and the suitability of RTILs as solvents in electrochemical experiments is considered. The application of RTILs as replacements for conventional solvents in gas sensors is reviewed, focussing on the electrochemistry observed in RTILs for the following gases: oxygen, a mixture of oxygen and carbon dioxide, and ammonia. The low volatility and high thermal stability of RTILs renders them advantageous for the development of robust sensors under extreme conditions. Finally, the possibility for use of RTILs as solvents in electrosynthesis is discussed, focussing on two ex les: the reactivity of electrogenerated bromine with cyclohexene, and the reduction of 4-nitrophenol. It is obvious that RTILs have the ability to offer many advantages over traditional solvents in the field of electrochemistry.
Direct electrochemistry of horseradish peroxidase immobilized in a chitosan–[C4mim][BF4] film: Determination of electrode kinetic parameters
Publisher: Elsevier BV
Date: 11-2008
DOI: 10.1016/J.BIOELECHEM.2008.07.008
Abstract: The direct electrochemistry of a HRP-chi-[C(4)mim][BF(4)] film (where HRP = horseradish peroxidase, chi = chitosan, and [C(4)mim][BF(4)] = the room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium tetrafluoroborate) has been studied by cyclic voltammetry on a glassy carbon electrode. The mechanism for the electrochemical reaction of HRP is suggested to be EC for the reduction, and CE for the following re-oxidation, as the oxidative peak potential remained approximately unchanged across the scan rate range. The half wave potential of HRP reduction was found to be pH dependent, suggesting that a concomitant proton and electron transfer is occurring. Using theoretical simulations of the experimentally obtained peak positions, the standard electron transfer rate constant, k(0), was found to be 98 (+/-16) s(-1) at 295 K in pH 7 phosphate buffer solution, which is very close to the value reported in the absence of ionic liquid. This suggests that the ionic liquid used here in the HRP-chi-[C(4)mim][BF(4)]/GC electrode does not enhance the rate of electron transfer. k(0) was found to increase systematically with increasing temperature and followed a linear Arrhenius relation, giving an activation energy of 14.20 kJ mol(-1). The electrode kinetics and activation energies obtained are identical to those reported for HRP films in aqueous media. This leads us to question if the use of RTIL films provide any unique benefits for enzyme rotein voltammetry. Rather the films may likely contain aqueous zones in which the enzymes are located and undergo electron transfer.
Ionophore-Assisted Electrochemistry of Neutral Molecules: Oxidation of Hydrogen in an Ionic Liquid Electrolyte
Publisher: American Chemical Society (ACS)
Date: 22-10-2019
DOI: 10.1021/ACS.JPCLETT.9B02666
Abstract: The electrochemical properties of gas molecules are of great interest for both fundamental and applied research. In this study, we introduce a novel concept to systematically alter the electrochemical behavior and, in particular, the redox potential of neutral gas molecules. The concept is based on the use of an ion-binding agent, or "ionophore", to bind and stabilize the ionic electrochemical reaction product. We demonstrate that the ionophore-assisted electrochemical oxidation of hydrogen in a room-temperature ionic liquid electrolyte is shifted by almost 1 V toward more negative potentials in comparison to an ionophore-free electrolyte. The altered electrochemical response in the presence of the ionophore not only yields insights into the reaction mechanism but also can be used to determine the diffusion coefficient of the ionophore species. This ionophore-modulated electrochemistry of neutral gas molecules opens up new avenues for the development of highly selective electrochemical sensors.
Electrochemical Oxidation and Sensing of Methylamine Gas in Room Temperature Ionic Liquids
Publisher: American Chemical Society (ACS)
Date: 12-08-2014
DOI: 10.1021/JP5061045
Examining the Electrochemical Nature of an Ionogel Based on the Ionic Liquid [P66614][TFSI] and TiO2: Synthesis, Characterization, and Quantum Chemical Calculations
Publisher: American Chemical Society (ACS)
Date: 14-06-2022
Interrogation of the Effect of Polymorphism of a Metal-Organic Framework Host on the Structure of Embedded Pd Guest Nanoparticles
Publisher: Wiley
Date: 20-02-2019
Abstract: Metal-organic frameworks (MOFs) are very promising host materials for nanoscale guest materials. However, some MOFs such as MIL-53 are known to undergo phase transitions which can complicate the guest particle size control. In this study, Pd nanoparticles embedded in Al-MIL-53 were synthesised via (a) electrodeposition and (b) gas-phase reduction. A thorough structural investigation revealed that each synthesis method most likely favoured a different phase of Al-MIL-53, presenting the possibility of MOF phase selection as a technique for size control of embedded nanoparticles. For the first time, we hereby report the use of pair distribution function analysis to successfully investigate the structure and morphology of guest particles embedded in a MOF host.
Effect of microelectrode array spacing on the growth of platinum electrodeposits and its implications for oxygen sensing in ionic liquids
Publisher: Elsevier BV
Date: 07-2021
Liquid Alloying Na–K for Sodium Metal Anodes
Publisher: American Chemical Society (ACS)
Date: 20-09-2021
Measuring the solubility of benzoic acid in room temperature ionic liquids using chronoamperometric techniques
Publisher: Wiley
Date: 05-08-2008
DOI: 10.1002/POC.1428
Fast responding hydrogen gas sensors using platinum nanoparticle modified microchannels and ionic liquids
Publisher: Elsevier BV
Date: 09-2019
DOI: 10.1016/J.ACA.2019.04.042
Abstract: From a safety perspective, it is vital to have fast responding gas sensors for toxic and explosive gases in the event of a gas leak. Amperometric gas sensors have been developed for such a purpose, but their response times are often relatively slow - on the order of 50 seconds or more. In this work, we have developed sensors for hydrogen gas that demonstrate ultra-fast response times. The sensor consists of an array of gold microchannel electrodes, electrodeposited with platinum nanoparticles (PtNPs) to enable hydrogen electroactivity. Very thin layers (∼9 μm) of room temperature ionic liquids (RTILs) result in an extremely fast response time of only 2 s, significantly faster than the other conventional electrodes examined (unmodified Pt electrode, and PtNP modified Au electrode). The RTIL layer in the microchannels is much thinner than the channel length, showing an interesting yet complex diffusion pattern and characteristic thin-layer behavior. At short times (e.g. on the timescale of cyclic voltammetry), the oxidation current is smaller and steady-state in nature, compared to macrodisk electrodes. At longer times (e.g. using long-term chrono erometry), the diffusion layer is large for all surfaces and extends to the liquid/gas phase boundary, where the gas is continuously replenished from the flowing gas stream. Thus, the current response is the largest on the microchannel electrode, resulting in the highest sensitivity and lowest limit of detection for hydrogen. These microchannel electrodes appear to be highly promising surfaces for the ultrafast detection of hydrogen gas, particularly at relevant concentrations close to, or below, the lower explosive limit of 4 vol-% H
Electrode Kinetic Studies of the Hydroquinone−Benzoquinone System and the Reaction between Hydroquinone and Ammonia in Propylene Carbonate: Application to the Indirect Electroanalytical Sensing of Am
Publisher: American Chemical Society (ACS)
Date: 29-12-2006
DOI: 10.1021/JP066704Y
Chapter 10: Electrochemical detection using ionic liquids
Publisher: The Royal Society of Chemistry
Date: 12-10-2016
DOI: 10.1039/9781782622529-00341
Abstract: Ionic liquids are relatively new additions to the field of electrochemical sensing. Despite that, they have had a significant impact, and several major areas are covered herein. This includes the application of ionic liquids in the quantification of heavy metals, explosives, and chemical warfare agents, and in biosensors and bioanalysis. Also highlighted are the significant advantages ionic liquids inherently have with regards to gas sensors and carbon paste electrodes, by virtue of their non-volatility, inherent conductivity, and ersity of structure and function. Finally, their incorporation with carbon nanomaterials to form various gels, pastes, films, and printed electrodes is also highlighted.
Modification of Microelectrode Arrays with High Surface Area Dendritic Platinum 3D Structures: Enhanced Sensitivity for Oxygen Detection in Ionic Liquids
Publisher: MDPI AG
Date: 17-09-2018
DOI: 10.3390/NANO8090735
Abstract: Electrochemical gas sensors are often used for identifying and quantifying redox-active analyte gases in the atmosphere. However, for erometric sensors, the current signal is usually dependent on the electroactive surface area, which can become small when using microelectrodes and miniaturized devices. Microarray thin-film electrodes (MATFEs) are commercially available, low-cost devices that give enhanced current densities compared to mm-sized electrodes, but still give low current responses (e.g., less than one nano ), when detecting low concentrations of gases. To overcome this, we have modified the surface of the MATFEs by depositing platinum into the recessed holes to create arrays of 3D structures with high surface areas. Dendritic structures have been formed using an additive, lead acetate (Pb(OAc)2) into the plating solution. One-step and two-step depositions were explored, with a total deposition time of 300 s or 420 s. The modified MATFEs were then studied for their behavior towards oxygen reduction in the room temperature ionic liquid (RTIL) [N8,2,2,2][NTf2]. Significantly enhanced currents for oxygen were observed, ranging from 9 to 16 times the current of the unmodified MATFE. The highest sensitivity was obtained using a two-step deposition with a total time of 420 s, and both steps containing Pb(OAc)2. This work shows that commercially-available microelectrodes can be favorably modified to give significantly enhanced analytical performances.
Array of water|room temperature ionic liquid micro-interfaces
Publisher: Elsevier BV
Date: 05-2011
Detection of sulfur dioxide at low parts-per-million concentrations using low-cost planar electrodes with ionic liquid electrolytes
Publisher: Elsevier BV
Date: 08-2020
Voltammetry in room temperature ionic liquids: Comparisons and contrasts with conventional electrochemical solvents.
Publisher: Wiley
Date: 28-01-2010
Abstract: The recent literature is surveyed to explore the nature of voltammetry in room temperature ionic liquids. The extent of similarities with conventional electrochemical solvents is reported and some surprising differences are noted.
The Electrochemical Reduction of Hydrogen Sulfide on Platinum in Several Room Temperature Ionic Liquids
Publisher: American Chemical Society (ACS)
Date: 30-04-2008
DOI: 10.1021/JP800819K
Electrochemical detection of explosive compounds in an ionic liquid in mixed environments: Influence of oxygen, moisture, and other nitroaromatics on the sensing response
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/CH18396
Abstract: From a security point of view, detecting and quantifying explosives in mixed environments is required to identify potentially concealed explosives. Electrochemistry offers a viable method to detect nitroaromatic explosive compounds owing to the presence of easily reducible nitro groups that give rise to a current signal. However, their reduction potentials can overlap with interfering species, making it difficult to distinguish particular compounds. We have therefore examined the effect of oxygen, moisture, and other nitroaromatic species on the cyclic voltammetry and square wave voltammetry of nitroaromatic compounds of a range of mixed environments, focussing on 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (DNT) as model analytes, and using the hydrophobic room-temperature ionic liquid (RTIL) [P14,6,6,6][NTf2] as the solvent. Oxygen (0–20% vol.) minimally affected the current of the first reduction peak of TNT in [P14,6,6,6][NTf2], but significantly affects the current for DNT. The impact of water (0 to 86% relative humidity), however, was much more dramatic – even in the hydrophobic RTIL, water significantly affected the currents of the analyte peaks for TNT and DNT, and gave rise to additional reduction features, further contributing to the current. Additionally, the voltammetry of other related di- and tri-nitro compounds (2,6-dinitrotoluene, 1,3-dinitrobenzene, 2,4,6-trinitrotoluene, 1,3,5-trinitrobenzene, and musk xylene) was also studied to understand how different substituents on the aromatic ring may affect the reduction potentials. A 50:50 mixture of TNT and DNT revealed that both analytes could be separately identified and quantified using square wave voltammetry. Overall, this information is useful in determining the effect of other species on the current signals of electrochemical explosive sensors, and reveals that it may be necessary to dry the aprotic RTIL electrolyte when used in humid environments.
Voltammetric Characterization of the Ferrocene|Ferrocenium and Cobaltocenium|Cobaltocene Redox Couples in RTILs
Publisher: American Chemical Society (ACS)
Date: 31-01-2008
DOI: 10.1021/JP710134E
Stable organic radicals and their untapped potential in ionic liquids
Publisher: CSIRO Publishing
Date: 19-08-2022
DOI: 10.1071/CH22126
Abstract: Stable organic radicals have an open shell structure that makes them suitable for use in a erse set of applications. Specifically, it is the reversible one-electron redox behaviour that makes these species suitable for energy storage and in molecular electronics. Maintaining chemical stability, low redox potential and charge transfer capabilities, are key to the further development of these materials. To date, researchers have largely focused on the the preparation of new molecules with improved redox capabilities for use in traditional solvents. More recently exploration into the use of ionic liquids to stabilise charged species and reduce side reactions has shown promise. Computational and preliminary experimental studies have explored the impact of ionic liquids on radical stabilisation, and notable improvements have been observed for nitroxide-based materials when traditional solvents are replaced by ionic liquids. However, these gains require significant refinement based on the identity of the radical species and the ionic liquid. In this highlight, we focus on the current state of using ionic liquids as solvents to stabilise organic radicals and suggestions on the future direction of the field.
Electrochemical studies of hydrogen chloride gas in several room temperature ionic liquids: mechanism and sensing
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5CP06656E
Abstract: The behaviour of HCl in six RTILs reveals significant reactions with [PF 6 ] − anions, but electrochemical sensing is still possible in RTILs with [NTf 2 ] − anions.
Highly efficient re-cycle/generation of LiCoO2 cathode assisted by 2-naphthalenesulfonic acid
Publisher: Elsevier BV
Date: 08-2021
Comparison of Hydrothermally-Grown vs Electrodeposited Cobalt Sulfide Nanostructures as Modified Electrodes for Oxygen Evolution and Electrochemical Sensing Applications
Publisher: The Electrochemical Society
Date: 05-2022
Abstract: A wide range of electrocatalysts have been developed and implemented for electrochemical applications over the last decades, with researchers typically using either a conventional synthesis method (followed by drop-casting or spray-coating onto the electrode), or directly electrodepositing the catalyst. However, a clear comparison of the different materials synthesis techniques, and how this affects the electrochemical applications, has been less explored. Herein, we report a direct comparison of fabricated cobalt sulfide (CoS) nanostructure-based electrodes prepared by two different methods for two applications: (a) electrochemical water splitting and (b) glucose sensing. CoS is grown in the form of nanoflowers and nanosheets via facile one-pot hydrothermal (HT) and electrodeposition (ED) methods, respectively. Characterization is performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). It is observed that the as-fabricated CoS-ED electrode demonstrated enhanced oxygen evolution reaction (OER) performance, a lower overpotential (∼166 mV at 10 mA cm −2 ), lower charge transfer resistance (∼372 Ω), a lower Tafel slope (86 mV dec −1 ), and better stability compared to the CoS-HT electrode. Moreover, the CoS-ED electrode-based sensor also exhibited better performance, higher sensitivity, better selectivity, and good stability for electrochemical glucose detection compared to the CoS-HT sensor.
Related Organisations
University Of Bristol
Location: United Kingdom of Great Britain and Northern Ireland
Schlumberger Cambridge Research
Location: United Kingdom of Great Britain and Northern Ireland
University Of Oxford
Location: United Kingdom of Great Britain and Northern Ireland
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