Template-assisted synthesis of accordion-like CoFe(OH)x nanosheet clusters on GO sheets for electrocatalytic water oxidation

Developing highly efficient, low-cost and stable electrocatalysts for oxygen evolution reaction (OER) is momentous to achieve the conversion and storage of sustainable energy. Herein, the CoFe(OH)x/GO composites with accordion-like CoFe(OH)x nanosheets clusters dispersed on graphene oxide (GO) sheets are prepared via a template-assisted route. It is found that the OER performance of the CoFe(OH)x/GO composites strongly depends on the content of GO and the mole ratio of Co/Fe. The optimized CoFe(OH)x/GO composites exhibit remarkably enhanced OER electrocatalytic activity in 1 M KOH with a low overpotential of 294 mV at 10 mA cm-2 and a small Tafel slope of 63.4 mV dec-1, which are far superior to the corresponding Co(OH)2/GO and bare CoFe(OH)x. The enhanced electrocatalytic activity can be ascribed to the regulated electronic structure surrounding the active metal sites by introducing Fe, the improved conductivity by GO for faster charge transfer, and the accordion-like hierarchical structure with increased accessible active sites. This work demonstrates a comprehensive strategy to improve the electrocatalytic performance of transition metal hydroxide based OER catalysts.

Automated summary

The study developed CoFe(OH)x/GO composites with optimized OER performance, showing significantly enhanced electrocatalytic activity in 1 M KOH. The enhanced activity is attributed to the improved electronic structure surrounding the active metal sites by introducing Fe, the enhanced conductivity by GO, and the hierarchical structure of the composites providing increased accessible active sites.