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amorphous and nano-crystalline structures of mechanically-alloyed Al-24.4%Fe(mole fraction) powder mixture

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中国有色金属学会会刊：英文版 1999年第4期9卷 747-752页

作者：黄斌 Shanghai Jiao Tong Univ Sch Mat Sci & Engn Shanghai 200030 Peoples R China Kyoto Univ Grad Sch Energy Sci Kyoto 606 Japan

Elemental powders of Al-24. 4 % Fe (mole fraction) alloy were mechanically-alloyed using a conventional type ball-milling. Not only Fe particles gradually disperse in Al matrix but also Al and Fe crystal grains are refined to the order of ten nanometers after ball-milling for 180 h. The am0rphization starts at the early stage of ball milling and proceeds gradually. Complete amorphization is confirmed by ball-milling for 720h. The amorphization of the Powders after ball-milled for 180 h can be promoted by heating up to 673 K,which suggests a possibility of producing amorphous material by appropriate ball-milling and subsequent heating.

关键词： crystal and amorphous structure mechanical alloying Al-Fe alloy

amorphous M0S2 confined in nitrogen-doped porous carbon for improved electrocatalytic stability toward hydrogen evolution reaction

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Nano Research 2019年第12期12卷 3116-3122页

作者： Shaojie Lu Wenjing Wang Shengshuang Yang Wei Chen Zhongbin Zhuang Wenjing Tang Caihong He Jiajing Qian Dekun Ma Yun Yang Shaoming Huang Key Laboratory of Carbon Materials of Zhejiang Province College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China State Key Lab of Organic-Inorganic Composites and Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China

Developing non-precious metal catalysts with high activity and stability for electrochemical hydrogen evolution reaction(HER)is of great significance in both scie nee and tech no *** this work,N-doped CMK-3,which was prepared with a casting method using SBA-15 as thehard template and ammonia as the nitrogen source,has been utilized to hold MoS2 and restrict its growth to form MoS2@N-CMK-3 *** a result,M0S2 was found to have poorly crystallized and the limited space of porous N-CMK-3 made its size much *** there are moreactive sites in ***,MoS2@N-CMK-3 has exhibited good electrocatalytic performance toward HER in acids with a quite small Tafelslope of 32 mV·dec^-*** more importantly,compared to MoS2@CMK-3,its stability has been greatly improved,which can be attributedto the interaction between M0S2 and nitrogen atoms avoiding aggregation and mass *** work provides an idea that doping a porouscarbon support with nitrogen is an effective way to enhance the stability of the catalyst.

关键词： M0S2 amorphous N-doped CMK-3 hydrogen evolution reaction(HER) stability

amorphous phase stability of NbTiAlSiNx high-entropy films

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Rare Metals 2018年第8期37卷 682-689页

作者： Wen-Jie Sheng Xiao Yang Jie Zhu Cong Wang Yong Zhang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083China Center for Condensed Matter and Materials Physics Departmentof Physics Beihang University Beijing 100191 China

In this study, high-entropy films with the compo- sition of NbTiA1SiNx were prepared by a reactive direct current （DC） magnetron sputtering technique, with different nitrogen flow rates （0, 4 and 8 ***^-1）. The microstructures and properties were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, high-resolution transmission electron microscopy （HRTEM）, nano-indenter and spectrophotometer. All of the as-deposited NbTiA1SiNx films are shown to have an amorphous structure, and the films exhibit high thermal stability up to 700℃. The maximum hardness and modulus values of the films reach 20.5 GPa （4 ***-1） and 206.8 GPa （0 ***^-l）, respectively. The films exhibit high absorption of the solar energy in the wavelength of 0.3-2.5 pm, which indicates that NbTiA1SiNx nitride film is a potential candidate solar selective absorbing coating for high-temperature photo-thermal conversion in the concentrated solar power project.

关键词： High-entropy film Sputtering amorphous Photo-thermal conversion Phase stability

amorphous and humidity caking: A review

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Chinese Journal of Chemical Engineering 2019年第6期27卷 1429-1438页

作者： Mingyang Chen Dejiang Zhang Weibing Dong Zhilong Luo Chao Kang Haichao Li Gang Wang Junbo Gong School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China College of Chemistry and Chemical Engineering QingHai Nationalities UniversityXining 810007China Xi'an Modern Chemistry Research Institute Xi'an 710000China Key Laboratory Modern Drug Delivery and High Efficiency in Tianjin University Tianjin 300072China The Co-Innovation Center of Chemistry and Chemical Engineering of Tianjin Tianjin 300072China

Caking of products is a common and undesired phenomenon in food, chemical, pharmaceutical, and fertilizer industries which leads to extra cost and irregular quality. In general, caking processes could be identified as amorphous caking or humidity caking. In this review, history of studying caking, formation, methods, and prospects of these two caking processes are summarized and discussed. The relevant studies from the 1920 s to today are mentioned briefly. According to the different properties(i.e. hygrocapacity, hygrosensitivity, mechanical properties, and diffusion behavior) of amorphous powders and crystals, the conditions and mechanisms of amorphous and humidity caking are discussed. It is summarized that glass transition, moisture sorption, quantitative methods characterizing caking, accelerated caking tests, and simulation of caking behaviors are the main aspects that should be studied for a caking process. The methods for these five aspects are reviewed. Potential research points are proposed including caking of mixed particles, caking with phase transition or polymorph transition,non-homogenous caking, and simulation of caking.

关键词： Agglomeration Particle Powder technology amorphous caking Humidity caking

amorphous carbon-based materials as platform for advanced highperformance anodes in lithium secondary batteries

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Nano Research 2021年第7期14卷 2053-2066页

作者： Jianwei Nai Xinyue Zhao Huadong Yuan Xinyong Tao Lin Guo College of Materials Science and Engineering Zhejiang University of TechnologyHangzhou 310014China School of Chemistry Beijing Advanced Innovation Center for Biomedical EngineeringBeihang UniversityBeijing 100191China

The growing concern for the exhaustion of fossil energy and the rapid revolution of electronics have created a rising demand for electrical energy storage devices with high energy density,for example,lithium secondary batteries(LSBs).With high surface area,low cost,excellent mechanical strength,and electrochemical stability,amorphous carbon-based materials(ACMs)have been widely investigated as promising platform for anode materials in the *** this review,we firstly summarize recent advances in the synthesis of the ACMs with various morphologies,ranging from zero-to three-dimensional ***,the use of ACMs in Li-ion batteries and Li metal batteries is discussed respectively with the focus on the relationship between the structural features of the as-prepared ACMs and their roles in promoting electrochemical ***,the remaining challenges and the possible prospects for the use of ACMs in the LSBs are proposed to provide some useful clews for the future developments of this attractive area.

关键词： amorphous carbon nanomaterials lithium secondary batteries energy storage

amorphous NiFeB nanoparticles realizing highly active and stable oxygen evolving reaction for water splitting

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Nano Research 2018年第3期11卷 1664-1675页

作者： Guang Liu Dongying He Rui Yao Yong Zhao Jinping Li Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization Research Institute of Special Chemicals Taiyuan University ofTechnology Taiyuan 030024 China

The development of highly efficient and inexpensive catalysts for oxygen evolving reactions （OERs） is extremely urgent for promoting the overall efficiency of water splitting. Herein we report the fabrication of a series of amorphous NiFeB nanoparticles with varying atomic ratios of Fe to （Ni ＋ Fe）（XFe） by a facile chemical-reduction method. The amorphous NiFeB （XFe=0.20） nanoparticles, combining the merits of in situ formation of borate-enriched NiFeOOH catalytic surface layers, intrinsic amorphous nanostructures, and an optimized degree of Fe doping, displayed highly active electrocatalytic performance towards the OER in a broad range of pH values （from alkaline to neutral conditions）. The catalyst exhibited a relatively low overpotential of 216 mV with a Tafel slope of 40 mWdec on Ni foam and 251 mV with a Tafel slope of 43 mV/dec on glassy carbon at 10 mA/cm2 in a 1 M KOH solution, demonstrating much greater OER efficiency than that of commercial RuO2. Long-term stability testing of the OER performance of NiFeB （XFe = 0.20） by chronoamperometry （overpotential （η） = 320 mV） over 200 h revealed no evidence of degradation. Facile, scalable synthesis and highly active water oxidation make the NiFeB nanoparticles very attractive for OER electrocatalysis.

关键词： amorphous NiFeB electrocatalyst oxygen evolving reaction water splitting

amorphous FeCoNi-S as efficient bifunctional electrocatalysts for overall water splitting reaction

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Chinese Chemical Letters 2023年第2期34卷 576-581页

作者： Runze He Chunyan Wang Ligang Feng School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

Developing bifunctional electrocatalysts for overall water splitting reaction is still highly desired but with large challenges. Herein, an amorphous Fe Co Ni-S electrocatalyst was developed using thioacetamide for the sulfuration of Fe Co Ni hydroxide during the hydrothermal process. The obtained catalyst exhibited an amorphous structure with hybrid bonds of metal-S bond and metal-O bonds in the catalyst system. The optimized catalyst showed a largely improved bifunctional catalytic ability to drive water splitting reaction in the alkaline electrolyte compared to the Fe Co Ni hydroxide. It required an overpotential of 280 m V and 80 m V(No-IR correction) to offer 10 m A/cm^(2)for water oxidation and reduction respectively;a low cell voltage of 1.55 V was required to reach 10 m A/cm^(2)for the water electrolysis with good stability for12 h. Moreover, this catalyst system showed high catalytic stability, catalytic kinetics, and Faraday efficiency for water splitting reactions. Considering the very low intrinsic activity of Fe Co Ni hydroxide, the efficient bifunctional catalytic ability should result from the newly formed hybrid active sites of metallic metal-S species and the high valence state of metal oxide species. This work is effective in the bifunctional catalytic ability boosting for the transition metal materials by facile sulfuration in the hydrothermal approach.

关键词： Bifunctional electrocatalyst amorphous Overall water splitting FeCoNi hydroxide Sulfuration

amorphous porous sulfides nanosheets with hydrophilic/aerophobic surface for high-current-density water splitting

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Chinese Chemical Letters 2023年第7期34卷 230-235页

作者： Xiaoli Wu Sheng Zhao Lijie Yin Luqi Wang Linlin Li Feng Hu Shengjie Peng Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China

The rational construction of electrocatalysts with desired features is significant but challenging for superior water splitting at high current density. Herein, amorphous Co Ni S nanosheets are synthesized on nickel foam(NF) through a facile structure evolution strategy and present advanced performance at high current densities in water splitting. The high catalytic activity can be attributed to the sufficient active sites exposed by the flexible amorphous configuration. Moreover, the hydrophilicity and aerophobicity of a-CoNiS/NF promote surface wettability of the self-supporting electrode and avoid the aggregation of bubbles, which expedites the diffusion of electrolyte and facilitates the mass transfer. As a result, the optimized electrode demonstrates low overpotentials of 289 and 434 m V at 500 m A/cm^(2) under alkaline conditions for hydrogen evolution reaction(HER) and oxygen evolution reaction(OER), respectively. Impressively, an electrolytic water splitting cell assembled by bifunctional a-Co Ni S/NF operates with a low cell voltage of 1.46 V@10 mA/cm^(2) and reaches 1.79 V at 500 mA/cm^(2). The strategy sheds light on a competitive platform for the reasonable design of non-precious-metal electrocatalysts under high current density.

关键词： Electrocatalysts Metal-organic frameworks amorphous High current density Overall water splitting

amorphous silicon from low-temperature reduction of silica in the molten salts and its lithium-storage performance

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Chinese Chemical Letters 2021年第2期32卷 598-603页

作者： Xi Huang Xuyun Guo Yicheng Ding Run Wei Shengnan Mao Ye Zhu Zhihao Bao Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology School of Physics Science and EngineeringTongji University.Shanghai 200092China Department of Applied Physics Research Institute for Smart EnergyHong Kong Polytechnic UniversityHong KongChina

amorphous silicon(a-Si) is one of the most promising anode-materials for the lithium-ion battery owing to its large capacity and superior fracture ***,a-Si is usually fabricated with the sophisticated chemical vapor deposition or pulse laser deposition in a limited *** this work,we have succes s fully pre pared a-Si spheres(~200 nm) by reducing the TiO2-coated silica spheres with Al powders in the molten salts at 300℃.The coated TiO2 layer acts as a protective layer for structural maintenance during the reduction and a precursor for *** doped Ti element may suppress the crystal growth of Si to facilitate the formation of *** observation with in-situ transmission electron microscopy(TEM) further reveals that lithiation kinetics of the synthesized a-Si is controlled by the interfacial *** Li^(+) diffusivity in a-Si determined from the observation is in the order of 10^(-14) cm^(2)/*** anode of a-Si spheres together with crystalline Si nanoparticles exhibits excellent electrochemical performance,delivering a reversible capacity of 1604 mAh/g at 4 A/g and a capacity retention of 78,3%after 500 *** low temperature reduction process reported in this study provides a low-cost method to fabricate a-Si nanostructures as high-capacity durable anode materials.

关键词： amorphous Molten salt Lithium-ion battery Silicon anode Doping