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Electron transfer kinetics in CdS/Pt heterojunction photocatalyst during water splitting

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Chinese Journal of Catalysis 2022年第10期43卷 2530-2538页

作者： Jianjun Zhang Gaoyuan Yang Bowen He Bei Cheng Youji Li Guijie Liang Linxi Wang Laboratory of Solar Fuel Faculty of Materials Science and ChemistryChina University of GeosciencesWuhan 430074HubeiChina Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices Hubei University of Arts and ScienceXiangyang 441053HubeiChina State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070HubeiChina College of chemistry and Chemical engineering Jishou UniversityJishou 416000HunanChina

Noble metal cocatalysts have shown great potential in boosting the performance of CdS in photocatalytic water ***,the mechanism and kinetics of electron transfer in noble-metal-decorated CdS during practical hydrogen evolution is not clearly ***,Pt-nanoparticle-decorated CdS nanorods(CdS/Pt)are utilized as the model system to analyze the electron transfer kinetics in CdS/Pt *** femtosecond transient absorption spectroscopy,three dominating exciton quenching pathways are observed and assigned to the trapping of photogenerated electrons at shallow states,recombination of free electrons and trapped holes,and radiative recombination of locally photogenerated electron-hole *** introduction of Pt cocatalyst can release the electrons trapped at the shallow states and construct an ultrafast electron transfer tunnel at the CdS/Pt *** CdS/Pt is dispersed in acetonitrile,the lifetime and rate for interfacial electron transfer are respectively calculated to be~5.5 ps and~3.5×10^(10) s^(−1).The CdS/Pt is again dispersed in water to simulate photocatalytic water *** lifetime of the interfacial electron transfer decreases to~5.1 ps and the electron transfer rate increases to~4.9×10^(10) s^(−1),confirming that Pt nanoparticles serve as the main active sites of hydrogen *** work reveals the role of Pt cocatalysts in enhancing the photocatalytic performance of CdS from the perspective of electron transfer kinetics.

关键词： Femtosecond transient absorption spectroscopy Photocatalytic water splitting CdS Electron transfer kinetics Trap state

Tellurium Filled Carbon Nanotubes Cathodes for Li-Te Batteries with High Capacity and Long-Term Cyclability

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SSRN 2023年

作者： Rao, Shaoqing Wu, Ruizhe Zhu, Zhu Wu, Jinsong Ding, Yao Mai, Liqiang School of Materials Science and Engineering Wuhan University of Technology Wuhan430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules College of Chemistry and Chemical Engineering Hubei University Wuhan430062 China

Li-Te batteries, compared with traditional lithium-ion batteries and Li-other group VIA elements (including O, S, Se) batteries, have shown overwhelming features of high specific volumetric capacity and superior electrical conductivity. These features make the Li-Te batteries possess great importance in modern portable electronics and electric vehicles with limited battery package size. However, the Achilles' Heel in Li-Te batteries is the huge volume change and inevitable shuttle effect of polytellurides during cycling. Herein, we synthesize a cathode material based on polycrystalline Te encapsulated in N-doped multiwall carbon nanotubes (Te-filled CNTs) by physical vapor transport (PVT) method. With unique spatial restriction of the CNT hosts, the electrochemically active Te content can be well preserved, and the prepared Te-filled CNTs cathodes deliver a high specific capacity of 590 mAh g-1 based on Te content. More importantly, the reaction kinetics and electrochemical reversibility of the cathodes have been significantly improved by using nanoscale cavities (4-6 nm) by which the polytellurides are stabilized. Meanwhile, a series of in situ Raman, XRD and TEM characterizations are carried out to reveal a two-step discharge/charge mechanism for Te-filled CNTs, which is the key for the excellent cycling stability. In addition, theoretical calculations prove that the encapsulated Te ensure a lower energy barrier for lithiation compared with bare CNT. This work sheds light on the nanoconfinement effect of CNT for improving the utilization and cycling stability of Te in Li-Te batteries, and provides a new strategy of designing high-performance group VIA element based cathodes. © 2023, The Authors. All rights reserved.

关键词： Cathodes

Enhanced Ablative Resistance of C/C Composites with Densified Zrb2-Based Ceramics by Incorporation of Mo as Interface Layer

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SSRN 2022年

作者： Zou, Hailiang Zhang, Jinyong Zou, Ji Ping, Hang Wang, Weimin Ren, Lin Fu, Zhengyi Zhang, Fan The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China Hubei LongZhong Laboratory Xiangyang441100 China

ZrB 2 -ZrC-SiC-Mo-C/C (ZZS-Mo-C/C) composites were synthesised in this study using reaction spark plasma sintering at a low temperature. Furthermore, we investigated the densification process, microstructure, interfacial bonding, ablative properties, and underlying mechanism of the ZZS-Mo-C/C composites. Before and after ablation, the specimen exhibited excellent interfacial bonding, indicating that the presence of the Mo-foil transition layer enables an optimal connection between ZZS and C/C. Additionally, SEM analysis revealed that the ZZS ceramics had a dense structure, thereby preventing oxygen from diffusing further into the matrix. The results indicate that ZZS-Mo-C/C exhibits superior oxidation resistance when exposed to an oxygen-acetylene flame. © 2022, The Authors. All rights reserved.

关键词： Oxidation resistance

Three-Dimensional Porous Polyimide Anode For High-Rate Lithium Ion Batteries

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SSRN 2023年

作者： Zhang, Qiuyitong Wei, Zijie Xu, Yuexin Lv, Ning Li, Hanyang Zhao, Xue Tian, Tian Wang, Yadong Tang, Haolin State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen Valley Foshan528200 China Xupu Central Primary School Yangzhou211400 China

Polymeric electrode materials suffer from poor electrical conductivity and slow transport kinetics, especially poor performance at high current density. Herein, a polyimide electrode structure with 3D ordered interconnected gradient pores is proposed for improving the lithium ion transport efficiency. The homogeneous mixed PMTA-PMMA composite is prepared by a simple one-pot method, and then the PMMA (polymethyl methacrylate) spherical porogenic agent is removed from it while synthesizing the polyimide material at high temperature to form a low curvature gradient pore structure. The large pores in the electrode can enhance the ion transport ability and improve the electrolyte infiltration rate, and the small pores can improve the active specific surface area and guide the deposition of lithium ions. The high specific capacity of 907mAh/g can be maintained even after 1000 cycles at 5A/g, which is about 3 times of the specific capacity of un-pored electrode material. This porous material with high active area and porosity is a potential electrode candidate for ultra-fast charging and discharging in lithium ion batteries, with high specific capacity and excellent cycling performance. © 2023, The Authors. All rights reserved.

关键词： Polyimides

富羟基PtNi纳米粒子作为海水中电化学析氢反应的高效催化剂（英文）

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Science China materials 2025年

作者：赵文英杨雄肖宇轩余菲田歌沈凌卢毅耿伟吴思明应杰 Ion Tiginyanu Kenneth I. Ozoemena 阳晓宇 State Key Laboratory of Silicate Materials for Architectures & State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & School of Chemistry Chemical Engineering and Life Sciences & Laoshan Laboratory & School of Materials Science and Engineering & International School of Materials Science and Engineering Wuhan University of Technology School of Chemical Engineering and Technology Sun Yat-sen University National Center for Materials Study and Testing Technical University of Moldova Molecular Sciences Institute School of Chemistry University of the Witwatersrand National Energy Key Laboratory for New Hydrogen-Ammonia Energy Technologies Foshan Xianhu Laboratory

Cl-吸附及腐蚀效应是Pt基催化剂在海水析氢反应（HER）中性能的主要障碍.虽然引入羟基是提升HER动力学和缓解氯毒化的有效策略,但在Pt基催化剂体系中实现这一策略仍具挑战性.本研究通过高温还原法制备了具有Ni空位（路易斯酸位点）的PtN...

Cl-吸附及腐蚀效应是Pt基催化剂在海水析氢反应（HER）中性能的主要障碍.虽然引入羟基是提升HER动力学和缓解氯毒化的有效策略,但在Pt基催化剂体系中实现这一策略仍具挑战性.本研究通过高温还原法制备了具有Ni空位（路易斯酸位点）的PtNi合金纳米颗粒.路易斯酸位点促进Ni-LDH载体上晶格羟基向表面羟基的转化.Ni-LDH的晶格羟基通过与路易斯酸位点相互作用,产生表面羟基并协同提升其表面亲水性.这种双功能特性既能促进水分子吸附,又可抑制Cl-吸附.优化后的PtNi/Ni-LDH在碱性真实海水中展现出优异的HER性能,仅需1 9 mV过电位即可达到1 0 mA cm-2电流密度,塔菲尔斜率为31 mV dec-1,并在100小时耐久性测试中具有优异的稳定性.该研究为通过定向羟基工程设计高效海水裂解催化剂提供了理论基础.

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Microstructural Evolution of Defects Under Proton Irradiation in Porous Cu

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SSRN 2023年

作者： Li, Honglin Wang, Hao Wen, Pin Huang, Zhifeng Yin, Guanchao Chen, Fei Hubei Longzhong Laboratory Xiangyang441106 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China International School of Materials Science and Engineering Wuhan University of Technology Wuhan430070 China Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics School of Science Wuhan University of Technology Wuhan430070 China Wuhan University of Technology China

The high specific strength and exceptional thermal insulating properties of porous metals make them an ideal choice for aerospace structural components and thermal insulation materials. However, in the space environment, proton irradiation leads to the formation of voids, bubbles, and dislocation loops, significantly compromising their physical and mechanical properties. To date, there has been limited attention to the radiation resistance properties in research related to porous metals. This study conducted proton irradiation experiments with a total dose of 1×1017 ions/cm2 on porous Cu. This study discusses and explains the irradiation-induced damage characteristics on the surface of porous Cu before and after proton irradiation. This provides insights into the radiation damage mechanisms within the porous Cu ligaments and the hydrogen release behavior on the ligament surface. Cascade recoil and collision-induced thermal spike effects modify material defect characteristics and crystal structure. This study elucidates the defect evolution mechanism of porous materials under proton irradiation, offering new insights for the design of other radiation-resistant porous materials as protective materials for future advanced space probes. © 2023, The Authors. All rights reserved.

关键词： Radiation damage

Three-Dimensional Porous Polyimide Anode For High-Rate Lithium Ion Batteries

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SSRN 2023年

作者： Zhang, Qiuyitong Wei, Zijie Xu, Yuexin Lv, Ning Li, Hanyang Tian, Tian Wang, Yadong Tang, Haolin Zhao, Xue State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen Valley Foshan528200 China Xupu Central Primary School Yangzhou211400 China

关键词： Polyimides

Preparation and Investigation of Zro2-Based Thermal Control Coatings Doped with Mgo

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SSRN 2023年

作者： Zeng, Xian Wang, Youyuan Wang, Meng Wang, Zheng Long, Ziqiang Li, Bei Cao, Qian Cheng, Xudong School of Materials Science and Engineering Wuhan University of Technology Wuhan430070 China Research Center for Materials Genome Engineering Wuhan University of Technology Wuhan430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China

In this study, MgO doped ZrO2 thermal control coatings were prepared using atmospheric plasma spraying technology. The phase composition, microstructure, optical properties of the coatings were characterized. The results showed that all the coatings possessed an obvious laminar structure. With the increase of MgO doping content, the chemicals of the coatings showed a trend of transition from monoclinic to cubic phase. Moreover, the solar absorptance (αs) effectively decreased, while the hemispherical emissivity (ΕH) increased. When the doping content reached 20 mol%, the ΕH/αs obtained a minimum value of 0.475, where the αs and ΕH was 0.399and 0.8395 correspondingly. Though the impurity levels introduced by the oxygen vacancies were beneficial to enhancing the intrinsic absorption in the 0.3~0.75 μm wave band, the decrease of free carrier concentration attenuated the free carrier absorption and weakened the emission property in the 0.75~7 μm wave band, resulting in a declining of αs. The enhancement of the hemispherical emissivity ΕH was attributed to the lattice distortion, which strengthen the radiation capability in the 7~25 μm wave band. © 2023, The Authors. All rights reserved.

关键词： Magnesia

In-situ ZrB2-hBN ceramics with high strength and low elasticity

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Journal of materials Science & technology 2020年第13期47卷 186-193页

作者： Ji Zou Guo-Jun Zhang Zheng-Yi Fu State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan430070China School of Metallurgy and Materials University of BirminghamB152TTBirminghamUK State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional MaterialsDonghua UniversityShanghai 201620China

ZrB2 ceramics with various hexagonal BN(hBN)additions up to 37 vol%were reactively densified by spark plasma sintering using powder mixtures containing ZrB2,ZrN and ***-boron based additives effectively promoted the densification process,ZrB2 ceramics reached>99%relative density at 2000℃and an applied pressure of 60 MPa with only 5 vol%in-situ formed hBN,whereas the relative density of pure ZrB2 was only 91.2%at the same *** thehBN contents,the morphology of hBN grains gradually changed from quasi-spherical to flake dominated,which has substantial influence on their mechanical ***-situ ZrB2-10 vol%hBN ceramics demonstrated high flexural strength of 597±22 MPa,relatively low Young’s modulus of 406 GPa and good machinability,especially for the impressively large strain to failure(1.47×10^-3)which is superior to most of their counterparts in the ZrB2 based particulate reinforced ceramics.

关键词： ZrB2 Reactive sintering Spark plasma sintering Boron nitride containing ceramics Mechanical property