Co-vacancy induced Pt filling combines defective Co3O4 enabling electrocatalytic hydrogen evolution

Abstract

It is crucial to design economically active and stable electrocatalysts for hydrogen evolution reactions (HER). Herein, we present a novel and efficient Ar plasma-assisted strategy for the construction of octahedral Co-vacancy induced heteroatom Pt-filling and oxygen vacancy enriched dual-deficient Co₃O₄ spinel nanosheets arrays (D-Pt-Co₃O₄) to enhance HER performance. The Ar plasma technique can efficiently generate vacancies on the oxide surface. This induces the formation of Pt-filling and oxygen vacancy. Theoretical calculations show that the synergistic effect of filling Pt atoms with oxygen vacancies effectively improves the electronic conductivity and optimizes the energy barriers. Meanwhile, the Pt atoms and Co atoms (mainly octahedral Co sites) act as active sites, contributing to the improved performance. A low overpotential of 27 mV is required for the D-Pt-Co₃O₄ at 10 mA cm^-2 in alkaline HER, outperforming that of the commercial Pt/C, and the turnover frequency under alkaline conditions is significantly improved. The present method highlights the concept of differential adsorption sites in vacancy-enhanced noble metal atom filling metal oxide catalysts for boosting hydrogen evolution.