Mixed-valence metallic compounds are a class of functional materials with peculiar electrochemical properties.Exploring the correlation between defects and corrosion resistance of mixed-valence metallic compounds is a...Mixed-valence metallic compounds are a class of functional materials with peculiar electrochemical properties.Exploring the correlation between defects and corrosion resistance of mixed-valence metallic compounds is a novel and interesting subject.Through an intelligently designed synergistic process of reduction and directed assembly,not only the directional generation of oxygen vacancies along the normal direction of the(010)crystal plane was achieved,but also the W_(18)O_(49)mixed-valence metal oxide(MVMO)with a single crystalline phase and an assembled ordered three-dimensional cluster structure of nanorods was obtained.Three attractive effects of oriented oxygen vacancies in W_(18)O_(49)MVMO were discovered.First,the oxygen vacancy channels realized the directional concentrated transport of oxygen atoms to form dense oxide passivation film.Second,the directional concentrated oxygen vacancies as active centers effectively solved the problem of difficult photoelectron leap and separation of pure-phase semiconductors,realizing photogenerated cathodic protection.Third,the high-energy vacancies endowed the material with antibacterial function,which contributed to the stable existence of the anti-corrosion system.The resistance value of W_(18)O_(49)MVMO as an anti-corrosion functional material was increased to more than 4.00 times that of the original metal protection layer.The experimental results obtained in this research were of great reference value for revealing the intrinsic mechanism of correlation between oxygen defect orientation of MVMOs and electrochemistry.展开更多
采用低温水热法一步制备出氧化物MO(M=Cu,Fe)与储氢合金La Ni_(3.81)Mn_(0.30)Co_(0.79)Al_(0.10)(AB_5合金)的复合材料.低温水热处理对合金的晶体结构没有影响,SEM-EDS照片显示氧化物均匀附着在合金颗粒表面.合金电极的电化学测试表明,...采用低温水热法一步制备出氧化物MO(M=Cu,Fe)与储氢合金La Ni_(3.81)Mn_(0.30)Co_(0.79)Al_(0.10)(AB_5合金)的复合材料.低温水热处理对合金的晶体结构没有影响,SEM-EDS照片显示氧化物均匀附着在合金颗粒表面.合金电极的电化学测试表明,Fe_2O_3@AB_5电极的最大放电容量为332.70 m Ah/g,Cu O@AB_5电极为342.61 m Ah/g,均大于未经处理的AB_5合金电极的323.62 m Ah/g.在1 500 m A/g的放电电流下,Fe_2O_3@AB_5电极和Cu O@AB_5电极的高倍率放电(HRD)分别比未处理的合金电极高13.61%和6.63%.在充放电循环250周期后,电极的容量保持率分别为S_(250)(Fe_2O_3@AB5)=63.17%,S250(Cu O@AB_5)=47.81%,S_(250)(AB_5)=61.33%.复合材料电极电化学性能改善的原因可能是生长在储氢合金表面的过渡金属氧化物具有催化活性并参与了电极充放电反应时的氧化还原反应.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.21878090)Opening Project of Material Corrosion and Protection Key Laboratory of Sichuan Province(No.2020CL04).
文摘Mixed-valence metallic compounds are a class of functional materials with peculiar electrochemical properties.Exploring the correlation between defects and corrosion resistance of mixed-valence metallic compounds is a novel and interesting subject.Through an intelligently designed synergistic process of reduction and directed assembly,not only the directional generation of oxygen vacancies along the normal direction of the(010)crystal plane was achieved,but also the W_(18)O_(49)mixed-valence metal oxide(MVMO)with a single crystalline phase and an assembled ordered three-dimensional cluster structure of nanorods was obtained.Three attractive effects of oriented oxygen vacancies in W_(18)O_(49)MVMO were discovered.First,the oxygen vacancy channels realized the directional concentrated transport of oxygen atoms to form dense oxide passivation film.Second,the directional concentrated oxygen vacancies as active centers effectively solved the problem of difficult photoelectron leap and separation of pure-phase semiconductors,realizing photogenerated cathodic protection.Third,the high-energy vacancies endowed the material with antibacterial function,which contributed to the stable existence of the anti-corrosion system.The resistance value of W_(18)O_(49)MVMO as an anti-corrosion functional material was increased to more than 4.00 times that of the original metal protection layer.The experimental results obtained in this research were of great reference value for revealing the intrinsic mechanism of correlation between oxygen defect orientation of MVMOs and electrochemistry.
文摘采用低温水热法一步制备出氧化物MO(M=Cu,Fe)与储氢合金La Ni_(3.81)Mn_(0.30)Co_(0.79)Al_(0.10)(AB_5合金)的复合材料.低温水热处理对合金的晶体结构没有影响,SEM-EDS照片显示氧化物均匀附着在合金颗粒表面.合金电极的电化学测试表明,Fe_2O_3@AB_5电极的最大放电容量为332.70 m Ah/g,Cu O@AB_5电极为342.61 m Ah/g,均大于未经处理的AB_5合金电极的323.62 m Ah/g.在1 500 m A/g的放电电流下,Fe_2O_3@AB_5电极和Cu O@AB_5电极的高倍率放电(HRD)分别比未处理的合金电极高13.61%和6.63%.在充放电循环250周期后,电极的容量保持率分别为S_(250)(Fe_2O_3@AB5)=63.17%,S250(Cu O@AB_5)=47.81%,S_(250)(AB_5)=61.33%.复合材料电极电化学性能改善的原因可能是生长在储氢合金表面的过渡金属氧化物具有催化活性并参与了电极充放电反应时的氧化还原反应.
