A MOF-Derived Co3O4/Ni-Co Sulphide Heterojunction for Ultra-Stable Sulphur Oxidation

Abstract

Replacing the sluggish oxygen evolution reaction (OER) with the thermodynamically favourable sulphur oxidation reaction (SOR) offers a promising route for energy-efficient H2 production coupled with environmental remediation. However, the practical deployment of SOR is hindered by rapid anode deactivation caused by sulphur poisoning and polysulphide corrosion. Herein, we report a robust hierarchical heterostructure comprising Ni-Co sulphide nanosheets anchored on a ZIF-L derived porous Co3O4 scaffold (Co3O4/NCS) to surmount this stability challenge. Leveraging the high surface area and structural stability of the metal-organic framework precursor, the conductive oxide backbone provides a mechanically stable interface that optimizes the electronic structure of the active sulphide phase. Consequently, the Co3O4/NCS electrode exhibits exceptional SOR performance, delivering a current density of 100 mA cm -2 at a low potential of 0.303 V vs. RHE and achieves an extraordinary operational lifetime of over 300 hours, significantly outperforming state-of-the-art catalysts. This work highlights the design of stable oxide/sulphide interfaces as a robust strategy for energy-saving H2 production coupled with environmental remediation.