Enhancing the electrochemical conversion of carbon dioxide to value-added products on zinc oxide-MXene nanocomposite

Developing efficient and sustainable catalysts for CO2 electroreduction is critical to addressing the rising atmospheric CO2 levels and mitigating climate change. This study presents a novel ZnO-MXene (Ti2C) nanocomposite as a high-performance electrocatalyst for CO2 conversion, offering a strategic approach for generating valuable carbon-based feedstocks. The ZnO-MXene nanocomposites were synthesized via the wet impregnation method and comprehensively characterized using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). Electrochemical performance was assessed through linear sweep voltammetry (LSV), cyclic voltammetry (CV), and controlled potential coulometry, with gas chromatography employed for product quantification. ZnO-MX10 and ZnO-MX2.5 exhibited high selectivity for CH4 (79.3 % Faradaic efficiency, FE) at −0.56 VRHE and CO (76.8 % FE) at −0.78 VRHE, while significantly suppressing competing H2 evolution. The synergistic interaction between ZnO and MXene enhances charge transfer, increases active sites, and improves surface area, leading to superior electrochemical performance. Overall, this work introduces a novel ZnO-MXene nanocomposite with dual selectivity for CO and CH4, enhanced electroactive surface, and long-term stability. Unlike conventional Zn-based catalysts, which exhibit either limited selectivity or rapid degradation, our composite achieves 79.3 % Faradaic efficiency for CH4 and 76.8 % for CO, while suppressing H2 evolution. This unique tunability and stability make ZnO-MXene an attractive alternative to noble metal-based electrocatalysts.