Synthesis of hierarchical transition metal oxyhydroxides in aqueous solution at ambient temperature and their application as OER electrocatalysts

作     者：Zongkun Chen Xingkun Wang Sascha Keßler Qiqi Fan Minghua Huang Helmut Cölfen Zongkun Chen;Xingkun Wang;Sascha Ke?ler;Qiqi Fan;Minghua Huang;Helmut C?lfen

作者机构：University of KonstanzPhysical ChemistryUniversitätsstraße 10Konstanz D-78457Germany School of Materials Science and EngineeringOcean University of ChinaQingdao 266100ShandongChina 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2022年第31卷第8期

页      面：89-97,I0003页

核心收录：

学科分类：081705[工学-工业催化] 08[工学] 0817[工学-化学工程与技术] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：funded by the Deutsche Forschungsgemeinschaft DFG and the Sino-German Center for Research Promotion(Grants GZ 1351 and CO 194/19-1) funded by a Chinese Scholarship Council stipend 

主　　题：Formation mechanism Hierarchical transition metal oxyhydroxides Aqueous solution Ambient temperature Oxygen evolution reaction 

摘      要：First-row(3 d)transition metal oxyhydroxides have attracted increasing attention due to their various *** investigating the oxidation mechanism and processing such materials into hierarchical architectures are greatly desired for their further development,it remains unclear how the oxidation state change occurs,and efforts to produce hierarchical oxyhydroxides in compliance with high ecological and economic standards have progressed ***,we describe a facile one-step coprecipitation route for the preparation of hierarchical CoOOH,NiOOH and MnOOH,which involves the diffusion of NH_(3)originating from ammonium hydroxide solution into an aqueous solution containing metal ion salts and K_(2)S_(2)O_(8).Comprehensive characterizations by scanning electron microscope,transmission electron microscopy,X-ray diffraction analysis,X-ray photoelectron spectroscopy,ultraviolet-visible spectroscopy and in situ p H measurement demonstrated that K_(2)S_(2)O_(8)induces the oxidation state change of metal ion species after the start of ***,it was found that,benefiting from the OH–concentration gradient created by the NH_(3)diffusion method and the suitable growth environment provided by the presence of K_(2)S_(2)O_(8)(high nucleation rate and secondary nucleation),the formation of hierarchical oxyhydroxide structures can be realized in aqueous solution at ambient temperature without the use of heat energy and additional structure-directing *** hierarchical CoOOH structures are performed as the electrocatalysts for the oxygen evolution reaction in alkaline media,which exhibit good activity with an overpotential of 320 m V at 10 m A cm^(-2)and a low Tafel slope of 59.6 m V dec^(–1),outperforming many congeneric ***,our study not only provides important insights to understand the formation mechanism of hierarchical oxyhydroxides,but also opens up new opportunities for the preparation of hierarchical oxyhydroxides via a f