Flaky cobalt phosphide-modified manganese iron oxide as a highly efficient OER catalyst

Abstract

Transition metal oxides with spinel structures prepared using the traditional method have defects, including a small specific surface area, large particle size and poor conductivity. These defects considerably limit their catalytic activity in oxygen evolution reactions (OERs). This study involves the preparation of manganese iron oxide modified using flaky cobalt phosphide. The obtained product exhibits good OER catalytic performance in a 1 M alkaline solution, which shows a low overpotential of 320 mV for the OER at 50 mA cm⁻². Furthermore, modified manganese iron oxide exhibits a low Tafel slope of 65.58 mVdec⁻¹. After the introduction of flaky cobalt phosphide, the increase of the active area and conductivity of manganese iron oxide significantly improves the OER performance of the sample. The OER performance of transition metal oxides with spinel structures can be further improved using the proposed method.