Phosphating-induced charge transfer on CoO/CoP interface for alkaline H2 evolution

Abstract Designing non-noble metal electrocatalysts toward alkaline hydrogen evolution reaction (HER) with high performance at a large current density is urgent. Herein, a CoO/CoP heterostructure catalyst (termed POZ) was designed by a phosphating strategy. The strong electron transfer on the interface of CoO/CoP was experimentally and theoretically proven. POZ showed a low overpotential of 236 mV at 400 mA/cm2, which was 249 mV lower than non-phosphated sample. It also exhibited a remarkable solar-to-hydrogen conversion efficiency of 10.5%. In this work, the construction of CoO/CoP interface realized by a simple phosphating strategy could provide an important reference to boost the HER performance on those materials not merely metal oxides.