Suppressed Jahn–Teller Distortion in MnCo <sub>2</sub> O <sub>4</sub> @Ni <sub>2</sub> P Heterostructures to Promote the Overall Water Splitting
Jing Ge, Wen Zhang, Jun Tu, Tao Xia, Sanping Chen, Gang Xie
Abstract
Abstract Jahn–Teller distortion in cobalt based spinel electrocatalysts causes poor activity and stability in potentially promising catalysts for water splitting. Here, a novel strategy to resolve this problem by interface engineering is reported, in which, Jahn–Teller distortion in MnCo 2 O 4 is significantly suppressed by in situ growth Ni 2 P nanosheets onto the MnCo 2 O 4 . The significance of interface engineering in suppressing Jahn–Teller distortion of Mn 3+ is further investigated by X‐ray photoelectron spectroscopy, the resulting increased catalytic activity and the effects of suppressed distortion demonstrated by density functional theory calculations. The resulting MnCo 2 O 4 @Ni 2 P heterostructures exhibit superior electrocatalytic activity for the both oxygen evolution reaction and hydrogen evolution reaction with small overpotentials of 240 and 57 mV at 10 mA cm ‐2 , respectively. Furthermore, the heterogeneous composite electrode demonstrates a superior current density of 10 mA cm ‐2 at a voltage of 1.63 V with excellent durability in a water splitting cell.