ORCID Profile
0000-0002-6432-6128
Current Organisation
Harbin Institute of Technology (Shenzhen)
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Publisher: Elsevier BV
Date: 02-2019
Publisher: American Chemical Society (ACS)
Date: 21-03-2018
Abstract: 4- tert-Butylpyridine ( t-BP) is commonly used in solid state dye-sensitized solar cells (ssDSSCs) to increase the photovoltaic performance. In this report, the mechanism how t-BP functions as a favorable additive is investigated comprehensively. ssDSSCs were prepared with different concentrations of t-BP, and a clear increase in efficiency was observed up to a maximum concentration and for higher concentrations the efficiency thereafter decreases. The energy level alignment in the complete devices was measured using hard X-ray photoelectron spectroscopy (HAXPES). The results show that the energy levels of titanium dioxide are shifted further away from the energy levels of spiro-OMeTAD as the t-BP concentration is increased. This explains the higher photovoltage obtained in the devices with higher t-BP concentration. In addition, the electron lifetime was measured for the devices and the electron lifetime was increased when adding t-BP, which can be explained by the recombination blocking effect at the surface of TiO
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.BIORTECH.2015.10.097
Abstract: A novel activated primary tank process (APT) was developed for recovering carbon source by fermentation and elutriation of primary sludge. The effects of solids retention time (SRT), elutriation intensity (G) and return sludge ratio (RSR) on this recovery were evaluated in a pilot scale reactor. Results indicated that SRT significantly influenced carbon source recovery, and mechanical elutriation could promote soluble COD (SCOD) and VFA yields. The optimal conditions of APT were SRT=5d, G=152s(-1) and RSR=10%, SCOD and VFA production were 57.0mg/L and 21.7mg/L. Particulate organic matter in sludge was converted into SCOD and VFAs as fermentative bacteria were significantly enriched in APT. Moreover, the APT process was applied in a wastewater treatment plant to solve the problem of insufficient carbon source. The outcomes demonstrated that influent SCOD of biological tank increased by 31.1%, which improved the efficiency of removing nitrogen and phosphorus.
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4RA10049B
Abstract: Mesoporous TiO 2 microbead films have been investigated as working electrode for solid state dye sensitized solar cells and 3.5% efficiency was achieved. Low trap density of microbead film leads to high voltage and fast electron transport.
Publisher: American Chemical Society (ACS)
Date: 17-08-2012
DOI: 10.1021/JP3052449
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3RA43228A
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.WATRES.2015.10.060
Abstract: The reactivity of dissolved effluent organic matter (EfOM) in the process of ozonation was examined. Under different ozone dosages (0.42 ± 0.09, 0.98 ± 0.11 and 2.24 ± 0.17 mgO3/mg DOC), the EfOM before and after ozonation could be classified into four fractions according to their hydrophobicities. By ozonation, the hydrophobic fractions, especially hydrophobic acid (HOA) and hydrophobic neutral (HON), were found to undergo a process of transformation into hydrophilic fractions (HI), of which the HOA were first transformed into HON, and then the majority of the HON fraction was later converted to HI by further ozonation. It was noticeable that after ozonation, the fluorescence intensity in the humic-like and protein-like regions decreased as indicated by the excitation and emission matrix (EEM) spectra for the hydrophobic fractions. By coupling the EEM spectra with the molecular size analysis using high performance size exclusion chromatography (HPSEC), the difference between the characteristic distributions of the humic-like and protein-like fluorophores were further revealed. It could thus be extrapolated that ozone might have preferentially reacted with the protein-like hydrophobic fraction with molecular weight (MW) less than 100 kDa. Moreover, by X-ray photoelectron spectroscopy (XPS) analysis, it was identified that with increasing ozone dosage (from 0 to 2.24 ± 0.17 mgO3/mg DOC), the aromaticity of HON decreased dramatically, while aliphatics and ketones increased especially at the low ozone dose (0.42 ± 0.09 mgO3/mg DOC). Of the EfOM fractions, the HON fraction would have a higher content of electron enriched aromatics which could preferentially react with ozone rather than the HOA fraction.
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C1CP23031J
Abstract: Two hole conductor materials, spiro-OMeTAD and P3HT, were compared in solid-state dye-sensitized solar cells. Two organic dyes containing one anchor unit (D35) or two anchor units (M3) were used in the comparison. Absorbed photon to current conversion efficiency close to unity was obtained for the devices with spiro-OMeTAD. Energy conversion efficiencies of 4.7% and 4.9% were measured for the devices with spiro-OMeTAD and the dyes D35 and M3, respectively. For the devices using the P3HT hole conductor the results were rather different comparing the two dye molecules, with energy conversion efficiencies of 3.2% and 0.5% for D35 and M3, respectively. Photo-induced absorption measurements suggest that the regeneration of the dyes, and the polymer infiltration, is not complete using P3HT, while spiro-OMeTAD regenerates the dyes efficiently. However, the TiO(2)/D35/P3HT system shows rather high energy conversion efficiency and electrochemical oxidation of the dyes on TiO(2) indicates that D35 have a more efficient dye to dye hole conduction than M3, which thereby might explain the higher performance. The dye hole conduction may therefore be of significant importance for optimizing the energy conversion in such hybrid TiO(2)/dye olymer systems.
Publisher: Elsevier BV
Date: 04-2021
Publisher: American Chemical Society (ACS)
Date: 07-05-2013
DOI: 10.1021/JA403344S
Abstract: Efficient solid state dye-sensitized solar cells (sDSCs) were obtained using a small hole transport material, MeO-TPD (N,N,N',N'-tetrakis(4-methoxyphenyl)benzidine), after an initial light soaking treatment. It was discovered that the light soaking treatment for the MeO-TPD based solar cells is essential in order to achieve the high efficiency (4.9%), which outperforms spiro-OMeTAD based sDSCs using the same dye and device preparation parameters. A mechanism based on Li(+) ion migration is suggested to explain the light soaking effect. It was observed that the electron lifetime for the MeO-TPD based sDSC strongly increases after the light soaking treatment, which explains the higher efficiency. After the initial light soaking treatment the device efficiency remains considerably stable with only 0.2% decrease after around 1 month (unsealed cells stored in dark).
Publisher: Elsevier BV
Date: 12-2018
Publisher: American Chemical Society (ACS)
Date: 20-03-2015
DOI: 10.1021/AC504851F
Abstract: Solid-state dye-sensitized solar cells (sDSCs) are devoid of such issues as electrolyte evaporation or leakage and electrode corrosion, which are typical for traditional liquid electrolyte-based DSCs. Poly(3,4-ethylenedioxythiophene) (PEDOT) is one of the most popular and efficient p-type conducting polymers that are used in sDSCs as a solid-state hole-transporting material. The most convenient way to deposit this insoluble polymer into the dye-sensitized mesoporous working electrode is in situ photoelectrochemical polymerization. Apparently, the structure and the physicochemical properties of the generated conducting polymer, which determine the photovoltaic performance of the corresponding solar cell, can be significantly affected by the preparation conditions. Therefore, a simple and fast analytical method that can reveal information on polymer chain length, possible chemical modifications, and impurities is strongly required for the rapid development of efficient solar energy-converting devices. In this contribution, we applied matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) for the analysis of PEDOT directly on sDSCs. It was found that the PEDOT generated in aqueous micellar medium possesses relatively shorter polymeric chains than the PEDOT deposited from an organic medium. Furthermore, the micellar electrolyte promotes a transformation of one of the thiophene terminal units to thiophenone. The introduction of a carbonyl group into the PEDOT molecule impedes the growth of the polymer chain and reduces the conductivity of the final polymer film. Both the simplicity of s le preparation (only application of the organic matrix onto the solar cell is needed) and the rapidity of analysis hold the promise of making MALDI MS an essential tool for the physicochemical characterization of conducting polymer-based sDSCs.
Publisher: American Chemical Society (ACS)
Date: 17-10-2013
DOI: 10.1021/JP406493V
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.BIORTECH.2016.06.068
Abstract: This study examined the distribution of carbon sources in two anaerobic anoxic oxic (AAO) sewage treatment plants in Xi'an and investigated the transformation characteristics and utilization potential of slowly biodegradable organic matters (SBOM). Results indicated under anaerobic and aerobic conditions, SBOM could be transformed at a rate of 65% in 8h into more readily biologically utilizable substrates such as volatile fatty acids (VFAs), polysaccharides and proteins. Additionally, non-biodegradable humus-type substances which are difficult to biodegrade and readily accumulate, were also generated. These products could be further hydrolyzed to aldehyde and ketone compounds and then transformed into substances with significant oxygen-containing functional groups and utilized subsequently. The molecular weights of proteinoid substances had a wide distribution and tended to decrease over time. Long hours of microbial reaction increased the proportion of micromolecular substances. This particular increase generated significant bioavailability, which can greatly improve the efficiency of nitrogen removal.
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.JHAZMAT.2016.12.043
Abstract: A novel hybrid ozonation-coagulation (HOC) process was developed for application in wastewater reclamation. In this process, ozonation and coagulation occurred simultaneously within a single unit. Compared with the conventional pre-ozonation-coagulation process, the HOC process exhibited much better performance in removing dissolved organic matters. In particular, the maximal organic matters removal efficiency was obtained at the ozone dosage of 1mgO
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3NR01542D
Abstract: We report for the first time the use of a perovskite (CH3NH3PbI3) absorber in combination with ZnO nanorod arrays (NRAs) for solar cell applications. The perovskite material has a higher absorption coefficient than molecular dye sensitizers, gives better solar cell stability, and is therefore more suited as a sensitizer for ZnO NRAs. A solar cell efficiency of 5.0% was achieved under 1000 W m(-2) AM 1.5 G illumination for a solar cell with the structure: ZnO NRA/CH3NH3PbI3/spiro-MeOTAD/Ag. Moreover, the solar cell shows a good long-term stability. Using transient photocurrent and photovoltage measurements it was found that the electron transport time and lifetime vary with the ZnO nanorod length, a trend which is similar to that in dye-sensitized solar cells, DSCs, suggesting a similar charge transfer process in ZnO NRA/CH3NH3PbI3 solar cells as in conventional DSCs. Compared to CH3NH3PbI3/TiO2 solar cells, ZnO shows a lower performance due to more recombination losses.
Publisher: SPIE-Intl Soc Optical Eng
Date: 10-03-2015
Publisher: American Chemical Society (ACS)
Date: 18-04-2013
DOI: 10.1021/JZ400638X
Abstract: We report on perovskite (CH3NH3)PbI3-sensitized solid-state solar cells using spiro-OMeTAD, poly(3-hexylthiophene-2,5-diyl) (P3HT) and 4-(diethylamino)benzaldehyde diphenylhydrazone (DEH) as hole transport materials (HTMs) with a light to electricity power conversion efficiency of 8.5%, 4.5%, and 1.6%, respectively, under AM 1.5G illumination of 1000 W/m(2) intensity. Photoinduced absorption spectroscopy (PIA) shows that hole transfer occurs from the (CH3NH3)PbI3 to HTMs after excitation of (CH3NH3)PbI3. The electron lifetime (τe) in these devices are in the order Spiro-OMeTAD > P3HT > DEH, while the charge transport time (ttr) is rather similar. The difference in τe can therefore explain the lower efficiency of the devices based on P3HT and DEH. This report shows that the nature of the HTM is essential for charge recombination and elucidates that finding an optimal HTM for the perovskite solar cell includes controlling the perovskite/HTM interaction. Design routes for new HTMs are suggested.
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.ENVPOL.2017.10.058
Abstract: The reactivity characteristics of humic acid (HA) with aluminium coagulants at different pH values was investigated. It revealed that the linear complexation reaction occurred between aluminum and humic acid at pH < 7, and the reaction rate increased as the pH increased from 2 to 6. While at pH = 7, most of the dosed aluminum existed in the form of free aluminum and remained unreacted in the presence of HA until the concentration reached to trigger Al(OH)
Publisher: Elsevier BV
Date: 07-2013
Publisher: American Chemical Society (ACS)
Date: 06-05-2014
DOI: 10.1021/JP412504S
Publisher: American Chemical Society (ACS)
Date: 19-01-2018
Abstract: Distribution characteristics and bio ersity of microbial communities were studied in a 1200 m pilot sewer system. Results showed that the dominant microorganisms, fermentation bacteria (FB), hydrogen-producing acetogen (HPA), sulfate-reducing bacteria (SRB) and methanogenic archaea (MA) changed significantly along the sewer systems, from start to the end. The distribution of the functional microorganisms could induce substrate transformation and lead to the accumulation of micromolecular organics (i.e., acetic acid, propionic acid and amino acid). However, substrate transformation induced by these microbes was affected by environmental factors such as oxidation-reduction potential, pH and dissolved oxygen. Changes in environmental conditions along the sewer resulted in the variation of dominant bioreactions. FB were enriched at the beginning of the sewer, while SRB and MA were found toward the end. Furthermore, based on Spearman rank correlation analysis of microbial communities, environmental factors and substrates, covariation between microbial community distribution and organics metabolization along the sewer was identified. This study could provide a theoretical foundation for understanding wastewater quality variation during transportation from sewers to treatment plants, therefore, promoting optimization of design and operation of wastewater treatment.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JHAZMAT.2018.10.090
Abstract: In this study, a novel TiO
Publisher: American Chemical Society (ACS)
Date: 13-10-2020
Publisher: Elsevier BV
Date: 07-2012
Publisher: Elsevier BV
Date: 10-2018
Publisher: Springer Science and Business Media LLC
Date: 08-07-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CP50365H
Abstract: 20 nm ZnO nanoparticles are used to fabricate the mesoporous photoanode of the CdS/CdSe quantum dot-sensitized solar cells by the simple doctor blade method. A maximum power conversion efficiency of 4.46% has been achieved, which indicated exciting prospects for ZnO nanoparticle based quantum dot-sensitized solar cells.
Publisher: American Chemical Society (ACS)
Date: 03-04-2014
DOI: 10.1021/LA404778P
Abstract: A new monitoring technique, which combines real-time in-situ CCD camera observation and reflectance spectra measurement, has been developed to study the growing and drying processes of evaporation-induced self-assembly (EISA). Evolutions of the reflectance spectrum and CCD camera images both reveal that the entire process of polystyrene (PS) EISA contains three stages: crack-initiation stage (T1), crack-propagation stage (T2), and crack-remained stage (T3). A new phenomenon, the red-shift of stop-band, is observed when the crack begins to propagate in the monitored window of CCD camera. Deformation of colloidal spheres, which mainly results in the increase of volume fraction of spheres, is applied to explain the phenomenon. Moreover, the modified scalar wave approximation (SWA) is utilized to analyze the reflectance spectra, and the fitting results are in good agreement with the evolution of CCD camera images. This new monitoring technique and the analysis method provide a good way to get insight into the growing and drying processes of PS colloidal self-assembly, especially the crack propagation.
Publisher: American Chemical Society (ACS)
Date: 13-11-2013
DOI: 10.1021/JZ4021266
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 10-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3TC30950A
No related grants have been discovered for Lei Yang.