Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ioni...Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ionic bridge in CN/BMO catalysts can boost the rapid transfer of photogenerated electrons from Bi2MoO6to g-C_(3)N_(4).And the synergy effect of g-C_(3)N_(4)and Bi2MoO6components remarkably enhance CO_(2)adsorption capability.CN/BMO-2 catalyst has the best performances for visible light-driven CO_(2)reduction compared with single Bi2MoO6and g-C_(3)N_(4),i.e.,its amount and selectivity of CO product are 139.50μmol g-1and 96.88%for 9 h,respectively.Based on the results of characterizations and density functional theory calculation,the photocatalytic mechanism for CO_(2)reduction is proposed.The high-efficient separation efficiency of photogenerated electron-hole pairs,induced by variable valence Mo^(5+)/Mo^(6+)ionic bridge,can boost the rate-limiting steps(COOH*-to-CO*and CO*desorption)of selective visible light-driven CO_(2)conversion into CO.It inspires the establishment of efficient photocatalysts for CO_(2)conversion.展开更多
采用碳酸盐共沉淀法和高温烧结工艺将一定量的Mo^(6+)掺杂到Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料中。利用XRD、SEM、EDS和恒流测试仪研究Mo^(6+)掺杂对Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料的晶体结构、...采用碳酸盐共沉淀法和高温烧结工艺将一定量的Mo^(6+)掺杂到Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料中。利用XRD、SEM、EDS和恒流测试仪研究Mo^(6+)掺杂对Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料的晶体结构、微观形貌和电化学性能的影响。结果显示,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)表现出更低的阳离子混排和优异的电化学性能。经过Mo^(6+)掺杂后的正极,由于Li^(+)高速的迁移速率,使得首次不可逆容量损失降低,并展现出更好的高倍率性能和优异的循环稳定性。在0.5C倍率下循环100周后,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)的容量保持率达到92.2%,远远大于Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的87.5%。另外,当放电倍率增大到5C时,Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的放电比容量要比Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)低21.0 m A·h/g。因此,采用Mo^(6+)掺杂改性Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料,可以有效提高锂电池的循环保持率和高倍率放电性能。展开更多
Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and 6% Mo super austenitic in acidified 3% NaCl solution at room tempe...Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and 6% Mo super austenitic in acidified 3% NaCl solution at room temperature.Potentiodynamic results showed that 6% Mo alloy possessed a remarkable resistance to crevice corrosion compared with 316L alloy when they are tested in the same solution. The breakdown potential at which passivity broke down for 316L alloy was 0.00 mV （SCE）. The corresponding value for 6% Mo alloy could not reach up to the potential value of 700 mV （SCE）. 316L alloy suffered extremely from crevice corrosion at room temperature （about 25℃）, which indicates that the critical crevice corrosion temperature, below which crevice corrosion does not occur, was lower than the test temperature. For 6% Mo alloy, the critical crevice corrosion temperature was higher than the testing temperature. Electrochemical parameters indicated that 6% Mo alloy exhibited higher crevice corrosion resistance than 316L alloy.展开更多
基金supported by the National Natural Science Foundation of China(21972166)the Beijing Natural Science Foundation(2202045)the National Key Research and Development Program of China(2019YFC1907600)。
文摘Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ionic bridge in CN/BMO catalysts can boost the rapid transfer of photogenerated electrons from Bi2MoO6to g-C_(3)N_(4).And the synergy effect of g-C_(3)N_(4)and Bi2MoO6components remarkably enhance CO_(2)adsorption capability.CN/BMO-2 catalyst has the best performances for visible light-driven CO_(2)reduction compared with single Bi2MoO6and g-C_(3)N_(4),i.e.,its amount and selectivity of CO product are 139.50μmol g-1and 96.88%for 9 h,respectively.Based on the results of characterizations and density functional theory calculation,the photocatalytic mechanism for CO_(2)reduction is proposed.The high-efficient separation efficiency of photogenerated electron-hole pairs,induced by variable valence Mo^(5+)/Mo^(6+)ionic bridge,can boost the rate-limiting steps(COOH*-to-CO*and CO*desorption)of selective visible light-driven CO_(2)conversion into CO.It inspires the establishment of efficient photocatalysts for CO_(2)conversion.
文摘采用碳酸盐共沉淀法和高温烧结工艺将一定量的Mo^(6+)掺杂到Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料中。利用XRD、SEM、EDS和恒流测试仪研究Mo^(6+)掺杂对Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料的晶体结构、微观形貌和电化学性能的影响。结果显示,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)表现出更低的阳离子混排和优异的电化学性能。经过Mo^(6+)掺杂后的正极,由于Li^(+)高速的迁移速率,使得首次不可逆容量损失降低,并展现出更好的高倍率性能和优异的循环稳定性。在0.5C倍率下循环100周后,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)的容量保持率达到92.2%,远远大于Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的87.5%。另外,当放电倍率增大到5C时,Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的放电比容量要比Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)低21.0 m A·h/g。因此,采用Mo^(6+)掺杂改性Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料,可以有效提高锂电池的循环保持率和高倍率放电性能。
文摘Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and 6% Mo super austenitic in acidified 3% NaCl solution at room temperature.Potentiodynamic results showed that 6% Mo alloy possessed a remarkable resistance to crevice corrosion compared with 316L alloy when they are tested in the same solution. The breakdown potential at which passivity broke down for 316L alloy was 0.00 mV （SCE）. The corresponding value for 6% Mo alloy could not reach up to the potential value of 700 mV （SCE）. 316L alloy suffered extremely from crevice corrosion at room temperature （about 25℃）, which indicates that the critical crevice corrosion temperature, below which crevice corrosion does not occur, was lower than the test temperature. For 6% Mo alloy, the critical crevice corrosion temperature was higher than the testing temperature. Electrochemical parameters indicated that 6% Mo alloy exhibited higher crevice corrosion resistance than 316L alloy.
