Cobalt-tuned nickel phosphide nanoparticles for highly efficient electrocatalysis

Abstract

The development of high-efficiency nonprecious electrocatalysts based on inexpensive and earth abundant elements is of great significance for renewable energy technologies. Here, Co-tuned nickel phosphide electrocatalysts have been prepared by a facile co-precipitation, oxidation, and phosphidation method by regulating the atomic ratio of Co/Ni. Co species could modulate the electronic state behaviors of NixPy and the hierarchically nanostructured Ni/Co-P shows highly electrochemical activity with a small Tafel slope of 45 mV dec−1 and an overpotential of 148 mV to reach the current density of 10 mA cm−2 in 0.5 M H2SO4 for hydrogen evolution reaction (HER). In 1.0 M KOH, an overpotential of 360 mV is required to achieve the current density of 10 mA cm−2 for oxygen evolution reaction (OER). Our research results suggest that doping metal is a useful route to improve the catalytic activity and our method may open up facile avenues to design other catalysts.