脱合金制备纳米多孔双金属氧化物NiMoO_4及其电化学性能  

Preparation and Electrochemical Performance of Nanoporous NiMoO_4 by De-alloying

作　　者：周琦[1] 郑斌[1] 李志洋[1] 王亚飞[1] 冯基伟[1] 

机构地区：[1]兰州理工大学材料科学与工程学院,兰州730050

出　　处：《无机化学学报》2017年第8期1416-1422,共7页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.51661018)资助项目

摘　　要：采用快速凝固与脱合金相结合的方法制备纳米多孔Ni-Mo合金,然后退火获得三维双连续纳米多孔NiMoO_4,采用XRD、SEM、TEM对多孔NiMoO_4的成分、形貌和结构进行表征,并通过循环伏安、恒电流充放电等方法测试多孔NiMoO_4电极的电化学性能。结果表明,Ni_5Mo_5Al_(90)和Ni_(2.5)Mo_(2.5)Al_(95)经脱合金和退火均可获得纳米多孔NiMoO_4,Mo元素对脱合金具有钉扎作用,可减小多孔合金的骨架和孔隙尺寸,由Ni_5Mo_5Al_(90)合金获得纳米多孔NiMoO_4表现出更为优异的超电容性能,其在1 A·g^(-1)电流密度比容量达708 F·g^(-1),当电流密度增加20 A·g^(-1),其比容保持率达57.1%。在4 A·g^(-1)电流密度下循环充放电1 000次,其比容保持率达91.2%。Nanoporous Ni-Mo alloy was prepared by a method of rapid quenching and de-alloying, and the samples were annealed to synthesize the nanoporous NiMoO4 material. The composition, morphology and microstructure of NiMoO4 were analyzed by XRD, SEM and TEM. The electrochemical performance was investigated by cyclic voltammetry and galvanostatic charge-discharge. The results show that the 3D bicontinuous nanoporous NiMoO4 can be prepared by de-alloying and annealling of the Ni5Mo5Al90 and Ni2.5Mo2.5Al95 alloy. Molybdenum with a low surface diffusivity has a pinning effect on mobile Ni atoms, thus leading to the decrease of the skeleton and pore size. The specific capacitance of nanoporous NiMoO4 prepared by Ni5Mo5Al90 is 708 Fg-1 at current density of 1 Ag-1 and its retention ratio remains at 57.1% when the current density increases to 20 Ag-1. After galvanostatic charge-discharge 1 000 cycles at 4 Ag-1, the retention ratio of specific capacitance is 91.2%.

关 键 词：快速凝固 脱合金化 纳米多孔NiMoO4 超级电容器 

分 类 号：TG146.1[一般工业技术—材料科学与工程] TQ138.1[金属学及工艺—金属材料]