Layered potassium cobalt pyrophosphate dihydrate (K2Co3(P2O7)2·2H2O): A novel efficient electrocatalyst for oxygen evolution reaction

Abstract

Alkali metal cobalt phosphates show great potential as electrocatalysts for oxygen evolution reaction (OER). Herein, a kind of layered potassium cobalt pyrophosphate dehydrate, i.e., K2Co3(P2O7)2·2H2O, was prepared by a simple hydrothermal method, and was proved to be a novel OER electrocatalyst for the first time. The as-developed K2Co3(P2O7)2·2H2O features a layered structure, large specific surface area, and special zigzag CoO6 octahedral chains, all of which contribute to the highly efficient OER performance. In specific, it achieves 10 mA cm−2 at an overpotential of only 296 mV and a Tafel slope of 40.2 mV dec−1 in 1.0 M KOH. Thus, this present work has opened a new pathway to develop alkali metal cobalt phosphates towards efficient and stable electrocatalytic oxygen evolution reaction.