Scalable synthesis of MOFs-derived ZnO/C nanohybrid: efficient electrocatalyst for oxygen evolution reaction in alkaline medium

One of the main goals of energy conversion research is to develop efficient, nonprecious, and stable electrocatalysts to replace deficient and unstable noble metal catalysts. Hence, this work described metal–organic frameworks (MOFs) derived ZnO/C hybrid via a hydrothermal route grown on the surface of conducting stainless steel substrate (SS). By using multiple physical techniques (XRD, FTIR, TEM, XPS, and EDX), we compared structural and morphological properties of ZnO/C hybrid and MOF-5 electrodes. The electrocatalytic behaviour of amiable and economical ZnO/C/SS catalyst was noticed in catalyzing oxygen evolution reaction (OER) in one mole KOH electrolyzer with low overpotential and excellent stability. Cyclic sweep voltammetry indicated that the ZnO/C/SS hybrid only needs an ultralow overpotential of 282 mV to achieve a current density of 10 mA cm⁻¹ for OER. In addition, ZnO/C/SS with a low Tafel slope of 39.3 mV/dec and higher 0.29 s⁻¹ turnover frequency can serve as a proficient electrocatalyst compared to commercial ZnO and MOF-5 electrodes. The stability of ZnO/C/SS hybrid electrocatalyst approaching minor chronoamperometric degradation after 55 h. The electrochemical response depicts that the successful synthesis of MOF-derived ZnO/C/SS catalyst provided abundant active centers and boosted an electron-rich environment to promote its future prosperity and facilitate practical applications for electrochemical water-splitting.