Design of pH-universal NiCoP nanowire electrocatalysts with tunable charge distribution

Abstract

It is desirable to develop highly active and stable electrocatalysts for industrial overall water splitting. Tailoring the d-band center is thought to be an effective strategy to promote the electrocatalytic activity. However, the current catalysts usually present the high absorption energy for water molecules. To solve this issue, we report heterogeneous Cr-doped NiCoP electrocatalysts. Due to the high conductivity of Cr ions, the prepared catalysts possess excellent hydrogen evolution performance in wide pH ranges. For alkaline environment, the overpotential is only 50.9 mV. Meanwhile, Cr–NiCoP-0.45 samples possess the overpotential of 279 mV@50 mA cm−2 for oxygen evolution reaction. They deliver a cell voltage of 1.70 V at 50 mA cm−2 for water splitting. Density functional theory calculation results confirm that Cr doping can not only promote the charge transfer but also reduce the d-band center.