ORCID Profile
0000-0003-4466-8398
Current Organisation
Uppsala University
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Publisher: Biomedical Research Network, LLC
Date: 21-01-2020
Publisher: Elsevier BV
Date: 02-2021
Publisher: Wiley
Date: 30-09-2019
Abstract: In situ transmission electron microscopy (TEM) is one of the most powerful approaches for revealing physical and chemical process dynamics at atomic resolutions. The most recent developments for in situ TEM techniques are summarized in particular, how they enable visualization of various events, measure properties, and solve problems in the field of energy by revealing detailed mechanisms at the nanoscale. Related applications include rechargeable batteries such as Li-ion, Na-ion, Li-O
Publisher: Elsevier BV
Date: 10-2021
Publisher: American Chemical Society (ACS)
Date: 07-07-2020
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 08-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0TA04191B
Abstract: Vanadium( iii ) oxide (V 2 O 3 ) derived, carbon integrated hydrated vanadium oxide (V 5 O 12 ·0.4H 2 O) as an extrinsic pseudocapacitive material for excellent lithium storage in lithium ion battery anodes.
Publisher: AIP Publishing
Date: 07-2019
DOI: 10.1063/1.5108849
Abstract: The thermal stability of all-inorganic halide perovskites is their key advantage over organic/hybrid halide perovskites. Here, in situ high-resolution transmission electron microscopy (HRTEM) was used to directly investigate crystallography dynamics of a CsPbBr3 perovskite at high temperature (up to 690 K). In high vacuum TEM conditions (∼10−5 Pa), CsPbBr3 nanocrystals possessed superb stability at temperatures below 690 K. By sealing the crystals in amorphous carbon, their melting and solidification processes were directly observed at temperatures of 840 K and 838 K, respectively. This study should be valuable for future perovskite-containing solar cells, lasers, light-emitting diodes, and photodetectors working at high temperatures.
Publisher: American Chemical Society (ACS)
Date: 21-02-2019
DOI: 10.1021/ACS.NANOLETT.9B00263
Abstract: Aluminum nitride (AlN) has a unique combination of properties, such as high chemical and thermal stability, nontoxicity, high melting point, large energy band gap, high thermal conductivity, and intensive light emission. This combination makes AlN nanowires (NWs) a prospective material for optoelectronic and field-emission nanodevices. However, there has been very limited information on mechanical properties of AlN NWs that is essential for their reliable utilization in modern technologies. Herein, we thoroughly study mechanical properties of in idual AlN NWs using direct, in situ bending and tensile tests inside a high-resolution TEM. Overall, 22 in idual NWs have been tested, and a strong dependence of their Young's moduli and ultimate tensile strengths (UTS) on their growth axis crystallographic orientation is documented. The Young's modulus of NWs grown along the [101̅1] orientation is found to be in a range 160-260 GPa, whereas for those grown along the [0002] orientation it falls within a range 350-440 GPa. In situ TEM tensile tests demonstrate the UTS values up to 8.2 GPa for the [0002]-oriented NWs, which is more than 20 times larger than that of a bulk AlN compound. Such properties make AlN nanowires a highly promising material for the reinforcing applications in metal matrix and other composites. Finally, experimental results were compared and verified under a density functional theory simulation, which shows the pronounced effect of growth axis on the AlN NW mechanical behavior. The modeling reveals that with an increasing NW width the Young's modulus tends to approach the elastic constants of a bulk material.
Publisher: Wiley
Date: 10-2022
Abstract: Surface functionalized activated carbon (SFAC) has been used for several applications, including adsorption, catalysis and energy storage materials. Existing chemical and physical activation methods for surface functionalization are mostly identified as expensive, inefficient, and non‐green methods. Plasma, known as the fourth state of matter, has recently been recognized as an attractive and sustainable method for introducing a higher degree of surface functionality to activated carbon. It also improves the bulk chemical structure and the properties of SFAC. The surface functionalization process is governed by discharge gas, discharge source, discharge efficiency and discharge time. The majority of researchers have utilized oxygen plasma as the discharge gas. However, ammonia, carbon dioxide, atmospheric air, specific gases such as chlorine and hydrogen sulfide, and neutral gases such as nitrogen and argon have also been used as the discharge gas. These plasma activations were conducted under different power conditions (W to kW) and varying treatment times (seconds to hours) using different plasma sources such as dielectric barrier discharge (DBD), arc, radio frequency (RF) and microwave (MW) for the surface functionalization. Most of the researchers have experienced both positive and negative co‐relationships between principal parameters and surface functional groups (SFGs), surface area, porosity and other surface features such as roughness and hydrophilicity. However, a comprehensive review on the effects of these parameters on the final material properties is lacking. Therefore, this Review focuses on the recent developments in the utilization of plasma as a surface activation technique for activated carbon. Furthermore, an in‐depth analysis of the relationship between experimental parameters and the resultant surface features of activated carbon is carried out and discussed. The functionalization mechanisms related to plasma activation have also been illustrated. The aging effect, which negatively impacts surface functionalized activated carbon, is also emphasized. Finally, the recent advances in applications of SFAC, challenges and future perspectives are discussed in detail.
Publisher: Wiley
Date: 03-06-2021
Abstract: This paper investigates the carbonization of cotton gin trash (CGT) into carbon structures shaped under the influence of different operating conditions including the impact of endogenous fatty acids impurities present in CGT. As expected, both KOH activation and high carbonization temperature increase the material surface area and porosity. Furan and arene groups are formed from 400 °C to 800 °C but the proportion of the furan groups are highest at 600 °C. This is due to the conversion of the fatty acids in CGT to furan units. XRD data reveals the presence of three aromatic layers at 400 °C, followed by structural rearrangement to the formation of five stacks aromatic layers at 800 °C consisting mainly of protonated and non‐protonated condensed arene groups. Interestingly, a reduction in the number of aromatic structures is observed if no acid pretreatment of CGT to remove inorganic impurities is conducted prior to pyrolysis to 600 °C. Two potential applications of the synthesised carbons are shown one for the formation of 5‐hydroxymethylfurfural (80%) from fructose, which compares favorably to other porous carbon materials produced under harsher conditions, and another derived CGT carbon material which shows a good uptake of hydrogen for storage.
Publisher: Wiley
Date: 14-12-2021
Publisher: Wiley
Date: 14-07-2021
Abstract: The world is currently in the midst of a climate crises and many across the globe are competing to find new technologies to create clean, and effective ways of harnessing renewable energy sources. However, this energy needs to be stored and the current systems simply would not last. Zinc‐ion batteries (ZIBs) with vanadium‐containing cathodes are a recently arising technology providing a cheap, safe, and eco‐friendly alternative to the current systems. Vanadium is a material that has long been used for electrochemical systems due to its large range of stable oxidation states. Most common is the vanadium oxide (V 2 O 5 ) renowned for its open layered framework and manipulatable structure. However, this is not the only vanadium‐containing material that is proposed for use in ZIBs. The vanadium family is comprised of four main sub‐categories under which materials can be classified: vanadium oxides, vanadium phosphates, vanadates, and O 2 ‐free vanadium compounds. This report delves into the specifics of each of these sub‐families to further develop the understanding of their functionality by highlighting their structural and morphological characteristics, aptitude for modification, and the corresponding electrochemical properties. Through this investigation, the application of these materials in ZIB systems is highlighted and future development aims considered.
Publisher: Elsevier BV
Date: 09-2020
Publisher: American Chemical Society (ACS)
Date: 06-2020
No related grants have been discovered for Dumindu Pasan Siriwardena Thanaweera Achchige.