Polythionine Coated on Au/Co3O4 Enhances the Performance for Hydrogen Evolution Reaction

Abstract

Developing a general, green and effective strategy to improve the hydrogen evolution reaction (HER) electrocatalyst is urgently needed but challenging. Herein, we report a novel conducting polymer/metal/metal oxide composite as HER catalyst prepared by a two-step strategy, in which the Au/Co3O4 is synthesized by a one-pot hydrothermal method, subsequently, cyclic voltammetry is employed to electropolymerize polythionine on the Au/Co3O4. It is demonstrated that the HER electrocatalytic activity of Au/Co3O4 is effectively improved by the coating polythionine layer. The optimal polythionine/Au/Co3O4 displays an excellent electrocatalytic ability towards HER with an overpotential of 168[Formula: see text]mV at [Formula: see text] and low Tafel slope of 79[Formula: see text]mV[Formula: see text]dec[Formula: see text] in 0.5[Formula: see text]M H2SO4, which is greatly superior to those of the Au/Co3O4 (an overpotential of 300[Formula: see text]mV at [Formula: see text] and tafel slope of [Formula: see text]. Interestingly, the HER performance of N-doped reduced graphene (N-rGO) can also be significantly boosted by the coating polythionine layers, indicating the multifunctionality of polythionine in the enhancement of HER performance of nano electrocatalysts.