Interface catalysis by Pt nanocluster@Ni3N for bifunctional hydrogen evolution and oxygen evolution

Abstract

Due to their importance for practical applications in energy conversion, resolving the kinetic issues of water-dissociation in alkaline media for Pt-based electrocatalysts remains an ongoing challenge. Herein, the electronic properties of Pt could be modified with a nickel nitride (Ni₃N) support through forming an interface of a low ratio of Pt nanoclusters (Pt NCs) via a simple impregnation approach combined with nitridation. 1.5Pt@Ni₃N-360 can offer excellent bifunctional performance for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) which is competitive with commercial IrO₂ and Pt/C catalysts under alkaline media. It shows a low overpotential at 10 mA cm⁻² (285 and 71 mV) and a small Tafel slope (57 and 48 mV dec⁻¹) for OER and HER, respectively. The excellent bifunctional electrochemical activity of 1.5Pt@Ni₃N-360 is due to the interface and synergetic effect between Ni₃N and dispersed Pt clusters, which changes the electron distribution of the material, so that the hydrogen adsorption energy tends to the optimal value (ΔG_H* ∼ 0). It is believed that the utilization of low-ratio Pt as an co-electrocatalyst with a variety of metal nitrides opens new horizons and opportunities to fabricate more efficient electrocatalysts for broad applications in energy-related devices.