Single-Layered Graphene Oxide-Ni-ZIF Composite as an Effective Electrocatalyst for CO₂ Reduction and Selective 4-Nitrophenol Reduction

Electrochemical CO2 reduction (ECR) is a promising strategy for mitigating greenhouse gas emissions, where CO2 is transformed to valuable chemicals. In this study, we report the preparation of a Ni/Zn-Im@SLGO composite-based electrocatalyst, synthesized through a facile sol–gel method, for efficient ECR and 4-nitrophenol reduction. The synergistic interplay among nickel, the zinc-imidazole framework, and single-layered graphene oxide (SLGO) creates abundant active sites, facilitating rapid electron transfer and enhancement in the electrocatalytic performance. The composite exhibited exceptional selectivity toward syngas production, achieving a maximum faradaic efficiency of 48% for CO and 32% for H2 at −1.1 V. Notably, it also demonstrated remarkable stability under tested conditions. Furthermore, the catalyst exhibited excellent activity for hydrogen evolution and formic acid generation at specific potentials, attributed to the catalytic properties of nickel. In addition to CO2 reduction, the Ni/Zn-Im@SLGO composite effectively converted 4-nitrophenol to high-value 4-aminophenol under galvanostatic electrolysis with remarkable efficiency (80% product conversion and 94% faradaic efficiency). These results demonstrate the catalyst’s potential for the economically and sustainably viable synthesis of essential molecules.