Phase-transfer synthesis of α-Co(OH)_2 and its conversion to CoO for efficient electrocatalytic water oxidation  

作　　者：Dingyi Guo Fangfang Chen Wei Zhang Rui Cao 

机构地区：[1]School of Chemistry and Chemical Engineering,Shaanxi Normal University [2]Department of Chemistry,Renmin University of China

出　　处：《Science Bulletin》2017年第9期626-632,共7页科学通报（英文版）

基　　金：the Fundamental Research Funds for the Central Universities (GK201603037);the Starting Research Funds of Shaanxi Normal University;the National Natural Science Foundation of China (21101170,21503126 and 21573139);the ‘‘Thousand Talents Program" of China

摘　　要：Water splitting is an attractive way to produce recyclable hydrogen energy resource. The oxygen evolution reaction(OER) is the rate-determine step of water electrolysis. The exploring of low-cost, highly efficient and durable electrocatalysts for OER is thus extremely important. In this work, we developed a facile two-phase protocol to fabricate an α-Co(OH)_2 using sodium oleate as the phase-transfer surfactant.The crystallinity and structure of the α-Co(OH)_2 was regulated by heat treatments toward enhanced electrocatalytic OER activity. With the calcination of the as-prepared α-Co(OH)_2 at 200 °C, a networked and well-dispersed CoO nanoparticles were formed. The CoO sample afforded an OER current density of 10 mA cm^(-2) under a low overpotential of 312 mV in a 1 mol L^(-1) KOH aqueous solution. The high activity of the CoO material is believed to be associated with its ultra-small particle size and plentiful open spaces in the material, both of which can provide abundant surface catalytic sites.Water splitting is an attractive way to produce recyclable hydrogen energy resource. The oxygen evolu- tion reaction （OER） is the rate-determine step of water electrolysis. The exploring of low-cost, highly effi- cient and durable electrocatalysts for OER is thus extremely important. In this work, we developed a facile two-phase protocol to fabricate an α-Co（OH）2 using sodium oleate as the phase-transfer surfactant. The crystallinity and structure of the α-Co（OH）2 was regulated by heat treatments toward enhanced elec- trocatalytic OER activity. With the calcination of the as-prepared α-Co（OH）2 at 200 ℃, a networked and well-dispersed CoO nanoparticles were formed. The CoO sample afforded an OER current density of 10 mAcm-2 under a low overpotential of 312 mV in a 1 mol L KOH aqueous solution. The high activity of the CoO material is believed to be associated with its ultra-small particle size and plentiful open spaces in the material, both of which can provide abundant surface catalytic sites.

关 键 词：Water oxidation Cobalt oxide Cobalt hydroxide Oxygen evolution reaction ELECTROCATALYSIS 

分 类 号：TQ116.21[化学工程—无机化工]