Electron Density Modulation of MoO2/Ni to Produce Superior Hydrogen Evolution and Oxidation Activities

Hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR) have aroused great interest, but the high price of platinum group metals (PGMs) limits their development. The electronic reconstruction at the interface of a heterostructure is a promising strategy to enhance their catalytic performance. Here, MoO2/Ni heterostructure was synthesized to provide effective HER in an alkaline electrolyte and exhibit excellent HOR performance. Theoretical and experimental analyses prove that the electron density around the Ni atom is reduced. The electron density modulation optimizes the hydrogen adsorption and hydroxide adsorption free energy, which can effectively improve the activity of both HER and HOR. Accordingly, the prepared MoO2/Ni@NF catalyst reveals robust HER activity (eta(10) = 50.48 mV) and HOR activity (j(0) = similar to 1.21 mA cm(-2)). This work demonstrates an effective method to design heterostructure interfaces and tailor the surface electronic structure to improve HER/HOR performance.

Automated summary

By synthesizing the MoO2/Ni heterostructure and electronically reconstructing at the interface, the study effectively improved the catalytic performance of hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR).