A hybrid zeolitic imidazolate framework-derived ZnO/ZnMoO4 heterostructure for electrochemical hydrogen production

Abstract

Sustainable hydrogen fuel supply through electrochemical water splitting requires highly efficient, low-cost and robust electrocatalysts. Interface engineering is of key importance to improve the catalytic performance in a heterogeneous electrocatalytic system. Herein, a porous microcubic framework composed of a ZnO/ZnMoO₄ heterostructure (ZnO@ZnMoO₄) is prepared by a hybrid zeolitic imidazolate framework-derived oxidation method, and it shows much enhanced hydrogen evolution reaction (HER) activity in alkaline media. The overpotential (at 10 mA cm⁻²) for ZnO@ZnMoO₄ is significantly reduced by 30% and 20% compared with those for virgin ZnO (v-ZnO) and polycrystalline zinc molybdenum oxide (PZMO), respectively. The enhanced electrocatalytic activity should be attributed to the ZnO/ZnMoO₄ heterostructure, which can synergistically facilitate the charge transport. This work provides a more structured design strategy for electrocatalysts for future electrochemical energy conversion systems.