Rational construction of high-active CO_(3)O_(4) electrocatalysts for oxygen evolution reaction

Rational construction of high-efficiency electrocatalysts for oxygen evolution reaction(OER)is critical for renewable-energy technologies,but it is highly challenging to rationally regulate their surface structures to improve the OER performance.Herein,we proposed a“model-etching”strategy to investigate chemical etching of CO_(3)O_(4).The cubic CO_(3)O_(4)nanocrystals enclosed by well-defined facets are synthesized as model crystals,whose uniform surface structures allow us to study the etching mechanism at atomic level.Etching kinetics study together with DFT calculations discloses that{111}facets,the highly active facets for OER,serve as etch-stop facets in the etching reaction and H_(2)SO_(4)molecules play a special role in creating surface Co2^(+),the active center of OER.These results direct us to rationally optimize the surface structures of CO_(3)O_(4) to develop highly active OER electrocatalysts.The favorable performance of overpotential(η)and the Tafel slope decrease even to 268 mV@10 mA·cm−2 and 74 mV·dec−1,respectively.In general,our study shows that chemical etching of model crystals could help us rationally construct high-efficiency electrocatalysts.