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Novel seed-assisted synthesis of indium tin oxide submicro-cubes and their resistivity

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Frontiers of Chemical Science and Engineering 2023年第5期17卷 557-569页

作者： Ting Liu Zhucheng Jiang Jiaxiang Liu Beijing Key Laboratory of Electrochemical Process and Technology for Materials College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Indium tin oxide films,an important n-type semiconductor oxide,show great prospects in optoelectronic device applications.Consequently,as a key raw material of targets for sputtering films,it is important to prepare low-resistivity indium tin oxide powders.Herein,low-resistivity indium tin oxide submicro-cubes are synthesized by a seed-assisted coprecipitation method.The effects of seed content,In^(3+)concentration,aging time,reaction temperature and calcination temperature on resistivity were investigated by single factor and orthogonal experiments.To ensure reliability and reproducibility of data,each experiment was repeated three times and resistivity of each sample was measured three times to obtain average value.The results indicated that optimal sample was matched with cubic phase In_(2)O_(3).The single-crystal indium tin oxide particles exhibited a regular cubic shape with a size of nearly 500 nm and low resistivity of 0.814Ω·cm.Compared with particles prepared by the conventional coprecipitation method,indium tin oxide submicro-cubes showed good dispersion.The presence of seed particles provided nucleation sites with lower energy barriers and promoted formation of submicro-cubes.The face-to-face contact among particles and good dispersion contributed to electron transfer,resulting in lower resistivity.The seed-assisted synthesis provides a novel way to prepare low-resistivity indium tin oxide submicro-cubes.

关键词： indium tin oxide submicro-cubes resistivity seed-assisted coprecipitation method orthogonal experiment

Effect of hydrogen impurities on hydrogen oxidation activity of Pt/C catalyst in proton exchange membrane fuel cells

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Clean Energy 2023年第1期7卷 139-147页

作者： Yufeng Qin Chaoyong Sun Shaojie Ke Rou Wen Yifan Wang Jing Ji Meiling Dou State key laboratory of Chemical Resource Engineering Laboratory of Electrochemical Process and Technology for materialsBeijing University of Chemical TechnologyBeijing 100029China

High-purity of hydrogen is vital to the guarantee of end usage in proton exchange membrane fuel cell(PEMFC)electric vehicles(EVs)with superior durability and low expense.However,the currently employed hydrogen,primarily from fossil fuel,still contains some poisoning impurities that significantly affect the durability of PEMFCs.Here,we investigate the poisoning effect of several typical hydrogen impurities(S^(2-),Cl^(-),HCOO^(-)and CO_(3)^(2-))on the hydrogen oxidation reaction(HOR)of the state-of-the-art carbon-supported platinum(Pt/C)catalyst used in the PEMFC anode.electrochemical results indicate that the electrochemically active surface area of Pt/C is hampered by these hydrogen impurities with reduced effective Pt reactive sites due to the competitive adsorption against hydrogen at Pt sites showing the extent of the poisoning on Pt sites in the order:S^(2-)>Cl^(-)>HCOO^(-)>CO_(3)^(2-).Density functional theory calculations reveal that the adsorption energy of S2-on Pt(111)is greater than that of Cl^(-),HCOO^(-)and CO_(2),and the electronic structure of Pt is found to be changed due to the adsorption of impurities showing the downshift of the d-band centre of Pt that weakens the adsorption of hydrogen on the Pt sites.This work provides valuable guidance for future optimization of hydrogen quality and also emphasizes the importance of anti-poisoning anode catalyst development,especially towards H_(2)S impurities that seriously affect the durability of PEMFCs.

关键词： hydrogen impurity poisoning effect electronic structure Pt/C hydrogen oxidation catalysis fuel cell

Lotus root-like RuIr alloys with close-packed(0001)branches:Strain-driven performance for acidic water oxidation

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Journal of Energy Chemistry 2024年第5期92卷 579-590页

作者： Mingyue Xiao Wanli Xu Rongchao Li Yanhui Sun Jingjun Liu Feng Liu Jun Gan Shixin Gao Beijing Key Laboratory of Electrochemical Process and Technology for Materials Beijing University of Chemical TechnologyBeijing 100029China Yunnan Precious Metals Lab Kunming 650100YunnanChina

Achieving composition tunability and structure editability of nanoalloys with high level strain may be an efficient strategy to remarkably boost catalytic performance toward oxygen evolution reaction(OER)in acidic water oxidation.Herein,lotus root-like RuIr alloys with native micro-strain were constructed by an epitaxial growth of Ru-richened hcp-(0001)branches on Ir-richened fcc-(111)seeds using a polyol thermal synthesis strategy.The resultant Ru_(60)Ir_(40) alloy shows an OER overpotential of 197 mV at 10 mA cm^(-2) and a Tafel slope of 46.59 mV dec^(-1),showing no obvious activity decay for 80 h continuous chronopotentiometry test in 0.5 M H_(2)SO_(4).The related characterizations including X-ray absorption fine structure(XAFS)spectroscopy and density functional theory(DFT)calculations show that that the remarkably improved activity of the lotus root-like alloy can be attributed to the(0001)facet-triggered strain,which can efficiently optimize the electronic band structure of the active metal and the weakening of the chemisorption of oxygen-containing substances to boost OER electrocatalysis.Therefore,this work provides a new strategy to designing a class of advanced electrocatalysts with high strain using diverse nanostructures as building materials for carbon-free clean energy conversion systems.

关键词： Rulr alloy Lotusroot-like structure Strain Oxygene volution reaction Activity

Progression in the Oxidation Stability of MXenes

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Nano-Micro Letters 2023年第7期15卷 306-323页

作者： Razium ASoomro Peng Zhang Baomin Fan Yi Wei Bin Xu State key laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China College of Chemical and materials Engineering Beijing Technology and Business UniversityBeijing 100048People’s Republic of China

MXenes are under the spotlight due to their versatile physicochemical characteristics. Since their discovery in 2011, significant advancements have been achieved in their synthesis and application sectors. However, the spontaneous oxidation of MXenes, which is critical to its processing and product lifespan, has gotten less attention due to its chemical complexity and poorly understood oxidation mechanism. This perspective focuses on the oxidation stability of MXenes and addresses the most recent advancements in understanding and the possible countermeasures to limit the spontaneous oxidation of MXenes. A section is dedicated to the presently accessible methods for monitoring oxidation, with a discussion on the debatable oxidation mechanism and coherently operating factors that contribute to the complexity of MXenes oxidation. The current potential solutions for mitigating MXenes oxidation and the existing challenges are also discussed with prospects to prolong MXene's shelf-life storage and expand their application scope.

关键词： MXenes Oxidation stability Antioxidation strategies Shelf-life of MXenes

Influence of the C-S-H Amount on [Cl^-]/[OH^-]Ratio of Simulated Concrete SPS and the Corrosion Susceptibility of Steel

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Journal of Wuhan University of technology(materials Science) 2017年第2期32卷 430-436页

作者：唐聿明 DUN Yuchao MIAO Yongfa ZHAO Xuhui ZUO Yu Beijing Key Laboratory of Electrochemical Process and Technology for Materials Beijing University of Chemical Technology

Two kinds of simulated concrete pore solutions（SPSs） were treated with different amounts of synthetic calcium silicate hydrate（C-S-H）. The variation of the [Cl^-]/[OH^-] ratio in SPS was measured and the corrosion susceptibility of carbon steel in the SPS was investigated with potentiodynamic polarization, EIS and weight lose tests. The experimental results showed that for the SPS at p H 12.5, as the amount of C-S-H increases, the [Cl^-]/[OH^-] ratio increases thereby causing an increase in the corrosion susceptibility of the steel. While for the SPS at p H 9.7, with increasing C-S-H amount, the drop amplitudes of both [Cl^-]/[OH^-] ratio and steel corrosion rate first decrease and then increase, and a 3% C-S-H addition shows the best inhibition effect. XPS results demonstrate that after C-S-H treating in p H 12.5 SPS the [Fe^（3＋）]/[Fe^（2＋）] ratio in the film on steel surface is reduced while in p H 9.7 SPS the [Fe^（3＋）]/[Fe^（2＋）] ratio is increased. The different effects of the C-S-H amount on the two SPSs and the steel corrosion behavior result from the influences of C-S-H on the SPS p H, which is related to the composition of the SPS.

关键词： C-S-H concrete SPS [Cl^-]/[OH^-] corrosion carbon steel

NIR-Ⅱ responsive Janus nanoparticles amplify immunogenic cell death for enhanced cancer immunotherapy

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Science China(Technological Sciences) 2024年第1期67卷 321-329页

作者： CHEN BeiBei GUO KangLi WANG HaoRan XU Fu-Jian WANG JuLin ZHAO NaNa State key laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China key laboratory of Biomedical materials of Natural Macromolecules(beijing University of Chemical technology) Beijing Laboratory of Biomedical MaterialsBeijing University of Chemical TechnologyBeijing 100029China College of materials Sciences and Engineering Beijing University of Chemical TechnologyBeijing 100029China Beijing Key Laboratory of Electrochemical Process and Technology for Materials Beijing University of Chemical TechnologyBeijing 100029China

Immunotherapy brings new hope for tumor treatment by inducing immunogenic cell death(ICD)of tumor cells.However,insufficient immunogenicity and low immune response rate greatly limit antitumor immunity.Herein,by optimizing the composition and morphology,the rational design of Janus nanoparticles composed of Fe_(3)O_(4) nanospheres and SiO_(2)nanorods was realized for enhanced cancer immunotherapy through amplified ICD.After glucose oxidase(GOx)was loaded by the Janus nanoparticles,the resultant M-FS-GOx consumes glucose at tumor sites to generate gluconic acid and hydrogen peroxide(H_(2)O_(2))for starvation therapy while the H_(2)O_(2)supply promotes the production of highly toxic·OH to achieve effective chemodynamic therapy(CDT).Under a 1064 nm light irradiation,the photothermal effect of M-FS-GOx enhances the enzyme activity of GOx for improved starvation therapy.Furthermore,both tumor-associated antigens released during the process of ICD and the intrinsic immunoadjuvant property of M-FS-GOx stimulate dendritic cell maturation to activate antitumor immune responses.This work provides a promising strategy for the construction of Janus nanoparticles to achieve enhanced cancer immunotherapy through combination therapy-amplified ICD.

关键词： Janus nanoparticles immunogenic cell death cancer immunotherapy

Facile synthesis of rutile TiO2/carbon nanosheet composite from MAX phase for lithium storage

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Journal of materials Science & technology 2019年第9期35卷 1977-1981页

作者： Zhaoruxin Guan Xiaoxue Wang Tingting Li Qizhen Zhu Mengqiu Jia Bin Xu State key laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for Materials Beijing University of Chemical Technology

Titanium oxide(TiO2),with excellent cycling stability and low volume expansion,is a promising anode material for lithium-ion battery(LIB),which suffers from low electrical conductivity and poor rate capability.Combining nano-sized TiO2 with conductive materials is proved an efficient method to improve its electrochemical properties.Here,rutile TiO2/carbon nanosheet was obtained by calcinating MAX(Ti3AlC2)and Na2C03 together and water-bathing with HC1.The lamellar carbon atoms in MAX are converted to 2D carbon nanosheets with urchin-like rutile TiO2 anchored on.The unique architecture can offer plentiful active sites,shorten the ion diffusion distance and improve the conductivity.The composite exhibits a high reversible capacity of 247 mA h g^-1,excellent rate performance(38 mA h g^-1 at 50 C)and stable cycling performance(0.014%decay per cycle during 2000 cycles)for lithium storage.

关键词： TiO2/C Composite Anode Lithium ion battery MAX

Effect of Particle Size on Target Sintering Behavior of Cubic ITO Nanopowders

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Journal of Wuhan University of technology(materials Science) 2020年第6期35卷 1098-1103页

作者： ZHAI Xiaoyu PENG Xiang MA Yunqian LIU Ting 刘家祥 Beijing Key Laboratory of Electrochemical Process and Technology for Materials College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China

The effect of particle size on the density and resistivity of ITO green bodies and targets was systematically investigated.The experimental results show that the relative density of ITO green bodies decreases with the increase of ITO particle size.When the particle size is 10.7 nm,the relative density of ITO green bodies rises to the maximum value of 56.6%.The resistivity declines exponentially with the increase of particle size,which satisfies the exponential equation of R=exp(-41.823 × d).When the particle size is 41.6 nm,the resistivity reaches the minimum value of 0.8 Ω·cm.The relative density of ITO target decreases with the increase of particle size.Fine particles can increase the driving force of densification in initial stage.Electron mobility,caused by grain boundary scattering,will increase due to the increase of particle size or the decrease of grain boundary potential.When the particle size is 10.7 nm,the target with compact grain stacking and low porosity shows a maximum relative density of 99.25%,and the resistivity reaches the minimum value of 0.34×10^-3 Ω·cm.

关键词： indium tin oxide nanoparticles particle size indium tin oxide target relative density resistivity

In-situ construction of hybrid artificial SEI with fluorinated siloxane to enable dendrite-free Li metal anodes

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Journal of Materiomics 2023年第2期9卷 318-327页

作者： Lei Wei Zhaoqing Jin Jianhao Lu Yang Guo Zilong Wang Gaoping Cao Jingyi Qiu Anbang Wang Weikun Wang State key laboratory of NBC Protection for Civilian Beijing102205China Research Institute of Chemical Defense Beijing100191China Beijing Key Laboratory of Electrochemical Process and Technology for Materials Beijing University of Chemical TechnologyBeijing100029China

Lithium(Li)metal anode holds great promise for high-energy-density rechargeable batteries.However,it suffers from the Li dendrites growth and uncontrollable side reactions with electrolyte due to the unstable solid electrolyte interphase(SEI)layer.Herein,we propose a facile strategy for the in-situ fabricate of organic-inorganic composite artificial SEI layers on Li surfaces,which consist of organic fluorinated siloxane and inorganic LiF-rich phases.The hybrid artificial SEI endows high mechanical strength(13.1 GPa)and Liþtransfer number(0.62).Such robust SEI protective layers can not only guide uniform nucleation and deposition of Li metal by facilitating uniform Li-ion distribution,but also prevent unfavourable side reactions.Accordingly,the protected metallic lithium anode(PMTFPS-Li)anode enables stable Li plating/stripping performance in symmetric cells for more than 300 h at 4 mA$h/cm^(2)under a high areal capacity of 4 mA/cm^(2).Moreover,the PMTFPS-Li/S cells could maintain more than 300 stable cycles at 0.5C and the PMTFPS-Li/LFP cells present excellent cycling performance(400 cycles at 1C)and enhanced rate capability(110.4 mA$h/g at 3 C).This work will inspire the design of artificial SEI on Li anodes for advanced Li metal batteries.

关键词： Fluorinated siloxane Lithium metal anode Dendrite growth Artificial SEI In-situ reaction