Stress-induced electronic structure modulation of manganese-incorporated Ni₂P leading to enhanced activity for water splitting

Abstract

The cornerstone of the emerging hydrogen economy is hydrogen production by water electrolysis with concomitant oxygen generation. Incorporating a third element in metal phosphides can tune the crystalline and electronic structure, hence improving the electrocatalytic properties. In this work, Mn-doped Ni₂P with varying ratios of Mn and Ni has been explored as excellent catalysts for water splitting. A complete cell made of the best catalyst Ni_1.5Mn_0.5P electrodes showed low voltage of 1.75 V at a current density of 10 mA cm^–2 due to enhanced electrical conductivity, induction of tensile stress, enhanced electrochemical surface area, and increased electric dipole upon Mn incorporation.