Interfacial engineering of hydrangea-like MnSe/NiSe heterostructure catalysts for methanol-assisted water splitting

Abstract

Replacing the oxygen evolution reaction (OER) with the methanol oxidation reaction (MOR) is an effective strategy for energy-saving production of hydrogen in the water splitting technique. In this work, we prepared hydrangea-like heterogeneous nanostructures composed of manganese selenide and nickel selenide (denoted as MnSe/NiSe), in which heterometallic nickel can be controllably introduced into manganese selenide to promote electron transfer from manganese selenide to nickel selenide. Electronic regulation optimizes the adsorption of water and methanol by heterojunction catalysts, forming dual active sites at the MnSe/NiSe heterointerface, thereby achieving excellent hydrogen evolution and methanol oxidation performance. The two-electrode cell utilizing MnSe/NiSe as a bifunctional catalyst necessitated electrolytic potentials of 1.53 V and 1.79 V to achieve current densities of 10 and 50 mA cm−2, respectively, which are clearly lower than those of the overall water splitting. This work offers an energy-saving method for hydrogen production.