Boosting oxygen evolution reactivity by modulating electronic structure and honeycomb-like architecture in Ni2P/N,P-codoped carbon hybrids

Abstract

Oxygen evolution reaction (OER) as the foremost stumbling block to generate cost-effective clean fuels has received extensive attention in recent years. But, it still maintains the challenge to manipulate the geometric and electronic structure during single reaction process under the same conditions. Herein, we report a simple self-template strategy to generate honeycomb-like Ni2P/N,P–C hybrids with preferred electronic architecture. Experiments coupled with theoretical results revealed that the synthesized catalyst has two characteristics: firstly, the unique honeycomb-like morphology not only enables the fully utilization of catalytic active sites but also optimizes the mass/electron transportation pathway, which favor the diffusion of electrolyte to accessible active sites. Secondly, N,P–C substrate, on the one hand, largely contributes the electronic distribution near Fermi level (EF) thus boosting its electrical conductivity. On the other hand, the support effect result in the upshift of d-band center and electropositivity of Ni sites, which attenuates the energy barrier for the adsorption of OH− and the formation of ∗OOH. In consequence, the optimized Ni2P/N,P–C catalysts feature high electrocatalytic activity towards OER (a low overpotential of 252 mV to achieve 10 mA cm−2) and 10 h long-term stability, the outstanding performance is comparable to most of transition metal catalysts. This work gives a innovative tactics for contriving original OER electrocatalysts, inspirng deeper understanding of fabricating catalysts by combining theoretical simulation and experiment design.