自模板法制备壳核结构NiCo_(2)O_(4)及其电催化性能研究

Preparation of core-shell structured NiCo2O4 by self-template method and its electrocatalytic performance

一种低成本、环保、容易制备的氧还原、氧析出双功能催化剂在环境保护和能源储存与转换方面至关重要。通过一步水热法制备了NiCo-甘油酸盐纳米球,并以其为前驱体,通过控制后续热处理过程中的加热速率,利用前驱体的非均匀收缩得到了单层壳核和双层壳核两种结构的NiCo_(2)O_(4)。结果表明:两种结构的材料其壳和核都是由纳米颗粒的NiCo_(2)O_(4)晶体组成,并且双层壳核结构的材料具有更高的比表面积。故其在碱性电解液中表现出优异的氧还原及氧析出双功能电催化性能和导电性。电化学测试结果表明,双层壳核结构的NiCo2O4具有5.58mA/cm^(2)的氧还原(ORR)极限电流密度,并且其氧析出(OER)在10mA/cm^(2)处的过电位仅为400.6mV。

A low cost,environmental protection,easily preparable dual-function catalyst for oxygen reduction and oxygen precipitation is very important in environmental protection and energy storage and conversion.In this paper,NiCo-glycerate nanospheres were prepared by one-step hydrothermal method.Using the nanospheres as precursors,NiCo_(2)O_(4) with single and double core-shell structures was obtained by controlling the heating rate during subsequent heat treatment and utilizing the non-uniform shrinkage of the precursor.The results showed that the shells and cores of both materials were composed of NiCo_(2)O_(4) crystals of nanoparticles,and the materials with double shell-core structure had higher specific surface area.Therefore,they exhibited excellent dual-function electrocatalytic performance and electrical conductivity for oxygen reduction and oxygen precipitation in alkaline electrolyte.The electrochemical test results indicated that the double core-shell NiCo_(2)O_(4) had an ORR limiting current density of 5.58mA/cm^(2),and the oxygen precipitation(OER)overpotential at OER 10mA/cm^(2) was only 400.6mV.