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Efficiency enhancement in photoelectrochemical water splitting: Defect passivation and boosted charge transfer kinetics of zinc oxide nanostructures via chalcopyrite/chalcogenide mix sensitization

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Physical Review Materials 2021年第12期5卷 125403-125403页

作者： Cigdem Tuc Altaf Nazrin Abdullayeva Ozlem Coskun Alihan Kumtepe İpek Deniz Yildirim Emre Erdem Maochang Liu Ali Bozbey Ertan Agar Mehmet Sankir Nurdan Demirci Sankir Micro and Nanotechnology Graduate Program TOBB University of Economics and Technology Sogutozu Caddesi No 43 Sogutozu 06560 Ankara Turkey Faculty of Engineering and Natural Sciences Sabanci University Orhanli Tuzla 34956 Istanbul Turkey International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an Shaanxi 710049 People's Republic of China Department of Electrical and Electronics Engineering TOBB University of Economics and Technology Sogutozu Caddesi No 43 Sogutozu 06560 Ankara Turkey Department of Mechanical Engineering Energy Engineering Graduate Program University of Massachusetts Lowell Lowell Massachusetts 01854 USA Department of Materials Science and Nanotechnology Engineering TOBB University of Economics and Technology Sogutozu Caddesi No 43 Sogutozu 06560 Ankara Turkey

ZnO thin films in nanorod (NR) and nanoflower (NF) morphologies were used as photoelectrode scaffolds for efficient visible-light-driven photoelectrochemical (PEC) water splitting process, where their decoration with copper indium gallium sulfide (CIGS) and indium sulfide (In2S3) layers resulted in significant PEC performance enhancement. ZnO NF/CIGS/In2S3 photoelectrodes exhibited a remarkably high PEC efficiency (∼6.0% applied bias photon-to-current efficiency, 83% incident photon-to-current efficiency) due to the negligible dark current, while ZnO NR/CIGS/In2S3 generated a photocurrent density of ***–2 at 0.4 V (vs Ag/AgCl), being one of the highest performances reported in the literature for copper-based chalcopyrite photoelectrodes so far. The interfacial photoelectrode-electrolyte charge transport dynamics, investigated via intensity-modulated photocurrent spectroscopy, exhibited a sevenfold increase in charge transfer efficiencies with a significant drop in surface recombination kinetics for ZnO NF after CIGS/In2S3 decoration. The obtained results show consistency with numerically modeled electric field distribution profiles and electron paramagnetic resonance results of ZnO NF, rationalizing the enhanced charge transfer rates for decorated samples and confirming the defect passivating nature of CIGS/In2S3.

关键词： Electrochemical properties Photoconductivity

Improve the Conversion Rate and Selectivity of Aromatic Monomers in Lignin Photocatalytic Conversion Reaction Via Phase Junction Cadmium Sulphide Nanoparticles and External Hydrogen Supplier

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SSRN 2023年

作者： Yue, Zongyang Shao, Shibo Yu, Jialin Lu, Guanchu Wei, Wenjing Huang, Yi Zhang, Kai Wang, Ke Fan, Xianfeng Institute for Materials and Processes School of Engineering The University of Edinburgh EdinburghEH9 3BF United Kingdom Petrochemical Research Institute PetroChina Company Limited Beijing102206 China Beijing Key Laboratory of Ionic Liquids Clean Process CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Multiphase Complex Systems Innovation Academy for Green Manufacture Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China Longzihu New Energy Laboratory Zhengzhou Institute of Emerging Industrial Technology Henan University Zhengzhou450000 China Beijing Key Laboratory of Emission Surveillance and Control for Thermal Power Generation North China Electric Power University Beijing102206 China

Photocatalysis has the potential for lignin valorisation to generate functionalised aromatic monomers, but its large-scale application has been limited by the slow conversion rate and the low selectivity to desirable products. In this work, record-high lignin model compound Cβ-O bonds cleavage rate and excellent selectivity to aromatic monomers has been achieved over the development of new hexagonal-cubic phase junction CdS nanoparticles, enhanced external hydrogen donor supply and hydrogen transfer, and improved separation efficiency of photo-excited electron-hole pairs. Water is employed as external hydrogen supplier, resulting in significant increase in the conversion rate of 2-Phenoxy-1-phenylethanol (PP-ol) as lignin model from 21.8% to 100% and the selectivity of aromatic monomers from ~45% to ~94% under 1h of visible light irradiation. 2-phenoxyacetophenone (PP-one) as by-product from PP-ol conversion can be further completely cleaved to aromatic monomers with assistance of TEA and reaction time is reduced from 2-12 hrs to10 min under visible-light irradiation. © 2023, The Authors. All rights reserved.

关键词： Lignin

Phosphorus Flame Retardant Modified Aramid Nanofiber Separator for Advanced Safety Lithium-Sulfur Batteries

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SSRN 2024年

作者： Liu, Jianwei Zhu, Lei Wang, Jianan Chai, Qinqin Sun, Shiyi Chen, Xin Wang, Xue Zhang, Yating Yan, Wei College of Chemistry and Chemical Engineering Xi’an University of Science and Technology Shaanxi Xi’an710054 China Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiao tong University Shaanxi Xi’an710049 China Xianggui Manganese Industry Co. Ltd. Shaanxi Province Ziyang County725300 China School of Physics and Electrical Engineering Weinan Normal University Shaanxi Weinan714099 China Xi'an Hantang Analysis & Test Co. Ltd Xi’an710201 China

Safety concerns have perennially impeded the large-scale implementation of high-energy-density storage systems. Nevertheless, because the intrinsic drawbacks of the commercial polyolefin separator are poor thermal stability and low flammability with a large thermal contribution, the development of an advanced separator that solves the above questions is imminent. In this work, gradient flame-retardant aramid nanofiber separators (T-PMIA) were synthesized by a single-step electrospinning method. The T-PMIA separator demonstrates excellent Li-ion diffusion and proficiently suppresses the "shuttle effect" through its plentiful multilevel beaded structure and robust anchoring of soluble polysulfides (Li2Sx), achieved by optimizing the functional groups P and -P-O. Moreover, the enhanced separator exhibits a rapid self-extinguishing feature (self-extinguishing time: 0.20 s) and impressive mechanical properties (tensile strength of up to 12.58 MPa and puncture force of 0.94 N). Accordingly, the T-PMIA separator still showed a stable cycling performance (maintain 901.7 mAg-1 after 100 cycles) even at high temperature (80 ℃). This simple separator strategy offers a highly competitive option for the large-scale production of high-safety lithium-sulfur (Li-S) batteries. This uncomplicated separator strategy presents a compelling solution for the large-scale production of high-safety lithium-sulfur (Li-S) batteries © 2024, The Authors. All rights reserved.

关键词： Separators

Performance enhancement for nanofluid-cooled microchannel heat sink

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Yingyong Jichu yu Gongcheng Kexue Xuebao/Journal of Basic Science and engineering 2012年第SUPPL.期20卷 169-180页

作者： Lin, Lin Wang, Xiaodong Wang, Zhenhua Department of Thermal Engineering University of Science and Technology Beijing Beijing 100083 China State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing 102206 China Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy North China Electric Power University Beijing 102206 China Xi'an Shaangu Power Co. LTD Xi'an 710075 China

Based on selecting the proper formulas of thermal conductivity and viscosity for nanofluids, a three-dimensional fluid-solid conjugated model was developed to analyze the effect of the heat sink structure, the nanoparticle kind, diameter and volume fraction, and the base fluid kind on the cooling performance of microchannel heat sink. The results showed that: (1) thermal dispersion effect caused by nanoparticle random motion enhanced the thermal convection of nanofluid thus enhances significantly the cooling performance of heat sink;(2) the enhancement of nanofluids was closely dependent on the heat sink structure and the dependence was distinct from the pure fluid, hence the heat sink structure was needed to be optimized for nanofluids as coolants;(3) as the nanoparticle volume fraction increases, the thermal resistance reduced and the pressure increased, the water-based Al2O3 nanofluid with 0.5% volume fraction was the optimal coolant which caused 10.1% decrease in the thermal resistance and only 0.38% increased in the pressure drop;(4) although the nanoparticle size had a small effect on the thermal resistance, nanoparticles with small diameter were recommended with consideration of stability of nanofluids;(5) Al2O3 nanoparticle was superior to TiO2 and CuO, and water was the better base fluid than ethylene glycol and engine oil.

关键词： Nanoparticles

Lithium Extraction from High Magnesium Salt Lake Brine with an Integrated Membrane Technology

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SSRN 2022年

作者： Ashraf, Muhammad Awais Usman, Muhammad Hussain, Iftikhar Ahmad, Faraz Guo, Shiwei Zhang, Lu State Key Laboratory of Multiphase Complex Systems CAS Key Laboratory of Green Process and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing100190 PR China University of Chinese Academy of Sciences Beijing100049 China Washington State University United States Department of Mechanical Engineering City University of Hong Kong 83 Tat Chee Avenue Kowloon Hong Kong Key Laboratory of Coal Science and Technology Taiyuan University of Technology Taiyuan030024 China North China Electric Power University Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control Department of Environmental Science and Engineering Baoding071000 China Faculty of Economics and Business

Lithium extraction is a great challenge from the high magnesium content salt solution. In this work, an integrated polyamide tight ultrafiltration (UF) and nanofiltration (NF) membranes are systematically investigated to separate Li+ from a high magnesium salt solution. Tight ultrafiltration UA001 and nanofiltration NF270 membranes in the integrated-cascade system not only increased Li+ permeation to 82.5% but also enhanced the high Mg2+ retention to 94.6% from the ternary salt solution of LiCl and MgCl2. The transport model was also developed to calculate the real retention of Li+ and Mg2+, under constant pressure mode. The separation efficiency SFLi/Mg for the ternary salt solution of LiCl+MgCl2+H2O was more than 15 at a constant pressure of 25 bars with an integrated membrane process, which was higher as compared to single-stage UF and NF270 membranes. Moreover, the high Mg2+/Li+ ratio was also reduced from 30 to 1.9 in the integrated-cascade membrane process. © 2022, The Authors. All rights reserved.

关键词： Magnesium compounds

Optimization design of flue gas temperature for Low-Low Temperature Electrostatic Precipitator

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Journal of Physics: Conference Series 2019年第1期1300卷

作者： Ke Sun Yu Yan Jiahao Jiang Lei Deng State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 China Huadian Electric Power Research Institute Co. LTD. Hangzhou 310030 China

Low temperature corrosion is one of the key issues in application of low-low temperature electrostatic precipitator. The concentration of SO3 affects the acid dew point temperature of flue gas. The exhaust temperature after the air preheater should be higher than the acid dew point temperature. The residual heat of flue gas is fully utilized by the low-temperature economizer. The efficiency of low-low temperature electrostatic precipitator is improved by the comprehensive effect of the condensation of SO3 on the surface of the fine particles, the decrease of the specific resistance of the particles and the agglomeration of the fine particles.

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Thermodynamic Analysis on of Skid-Mounted Coal-bed Methane Liquefaction Device using Cryogenic Turbo-Expander

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IOP Conference Series: Materials Science and engineering 2017年第1期278卷

作者： Shuangtao Chen Lu Niu Qiang Zeng Xiaojiang Li Fang Lou Liang Chen Yu Hou State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 PR China Xinjiang Coal Research Institute Urumqi 830091 PR China

Coal-bed methane (CBM) reserves are rich in Sinkiang of China, and liquefaction is a critical step for the CBM exploration and utilization. Different from other CBM gas fields in China, CBM distribution in Sinkiang is widespread but scattered, and the pressure, flow-rate and nitrogen content of CBM feed vary significantly. The skid-mounted liquefaction device is suggested as an efficient and economical way to recover methane. Turbo-expander is one of the most important parts which generates the cooling capacity for the cryogenic liquefaction system. Using turbo-expander, more cooling capacity and higher liquefied fraction can be achieved. In this study, skid-mounted CBM liquefaction processes based on Claude cycle are established. Cryogenic turbo-expander with high expansion ratio is employed to improve the efficiency of CBM liquefaction process. The unit power consumption per liquefaction mole flow-rate for CBM feed gas is used as the object function for process optimization, compressor discharge pressure, flow ratio of feed gas to turbo-expander and nitrogen friction are analyzed, and optimum operation range of the liquefaction processes are obtained.

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Au [email protected] @ZnIn 2 S 4 nanosheets with significantly enhanced visible-light photocatalytic H 2 evolution: The effect of different Au positions on the transfer of electron-hole pairs

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Applied Catalysis B: Environmental 2021年 282卷

作者： Siman Mao Jian-Wen Shi Guotai Sun Dandan Ma Chi He Zengxin Pu Kunli Song Yonghong Cheng State Key Laboratory of Electrical Insulation and Power Equipment Center of Nanomaterials for Renewable Energy School of Electrical Engineering Xi'an Jiaotong University Xi'an 710049 China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 Shaanxi China

Herein, a new type of photocatalysts, Au [email protected] @ZnIn 2 S 4 nanosheets ( [email protected] @ZIS), is elaborately designed for the photocatalytic H 2 evolution from water splitting, where Au nanodots (NDs) are anchored in the pore space of thiol-functionalized UiO66 metal-organic framework (MOF) and ZnIn 2 S 4 nanosheets are wrapped around the UiO66 MOF containing Au NDs. It is found that the different Au positions have a grateful effect on the transfer of photogenerated charge carriers. In [email protected] @ZIS, the photoexcited electrons transfers from ZnIn 2 S 4 to UiOS and then to Au NDs, establishing a smooth transmission channel of electrons. As expected, the optimal sample (Au 4 @ [email protected] 40 ) presents a high photocatalytic H 2 production rate of 391.6 μmol/h (10 mg of catalyst) under visible light irradiation, which is 435.1, 61.2 and 10.2 times higher than that of the pure UiOS, ZnIn 2 S 4 and [email protected] , respectively.

关键词： Photocatalysis Hydrogen evolution Metal-organic framework Thiol- functionalization Au nanodots

X-Ray Computed Tomography (Xct) Study of Jetting in a Fluidized Bed: Effects of Two-Component Fluidization

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SSRN 2024年

作者： Xiang, Zhong Chen, Xi Liu, Shuguang Heindel, Theodore J. Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and Environment Southeast University Nanjing210096 China Institute of Science and Technology for Carbon Neutrality Southeast University Nanjing210096 China Center for Multiphase Flow Research and Education Department of Mechanical Engineering Iowa State University AmesIA50011 United States

Fluidization of non-spherical particles is commonly found in the biomass and solid waste processing industry, and the jetting characteristic above the aeration plate is critical to the fluidization performance of these particles. In this study, cylindrical particles are used as typical non-spherical particles and co-fluidized with small bed material particles. X-ray computed tomography (XCT) is used to reconstruct the 3D structure of the aeration plate region, allowing for the identification of individual aeration jets. The effects of jet velocity (Uj), cylindrical particle mass fraction (ω), cylindrical particle density (ρi), and the cylindrical particle sphericity () on jet shape and volume are investigated. The experimental results indicate that decreasing the cylindrical particle mass fraction (ω) and particle density (ρi) increases the jet length (L), maximum jet diameter (D), and maximum jet volume (V), but have little effect on the jet half angle (θ). The cylindrical particle density (ρi) is the most sensitive factor for jet shape, while the effect of cylinder particle sphericity () on jet shape is insignificant. A correlation of jet length (L) in a two-component fluidized bed with cylindrical particles and bed material is proposed based on all the experimental results. © 2024, The Authors. All rights reserved.

关键词： Fluidization