Synergistic Coupling of MoS 2 with Electron-Rich MXene for CO 2 Conversion to Ethanol under Visible Light

The efficient photocatalytic CO 2 reduction to C 2 products remains a significant challenge due to sluggish multielectron transfer kinetics and C–C coupling. In this study, MoS 2 nanocrystal-decorated Ti 3 C 2 MXene heterostructured photocatalysts with varied loading concentrations have been synthesized using a facile hydrothermal method to enhance selective CO 2 reduction to ethanol under visible light. The optimized MS-TC-10 heterostructure exhibits enhanced ethanol production (1633.8 μmol/g), 1.8 times higher than that of bare MoS 2, along with improved selectivity (58.12%) and quantum efficiency (1.5%). The broadening of Raman peaks, shifts in Ti 2p, Mo 3d, and S 2p binding energies in the XPS spectrum and a hybrid magnetic signature (sharp and broad peaks at g = 2.013 and 1.94, respectively) in EPR suggest intimate interfacial coupling and electronic interaction between the MoS 2 and Ti 3 C 2 MXene. Further, CO 2 -TPD and FTIR studies provided insights into the CO 2 reduction pathway involving the formation of intermediates HCOO –, HCO 3 –, and carbonate species. CO 2 -TPD analysis of the MS-TC-10 heterostructure reveals two broad desorption peaks, corresponding to the weak and strong CO 2 adsorption sites. The prominent high-temperature desorption peak indicates strong CO 2 binding and thereby predominating C 2 H 5 OH formation. The overall improved activity is attributed to increased surface-active sites, broadened light harvesting, optimal band structure alignment, and efficient charge transfer across the MoS 2 –MXene interface. These factors collectively prolong charge carriers’ lifetime, eventually suppressing their recombinations and facilitating a multielectron pathway for C 2 product formation. In brief, these results suggest strong CO 2 adsorption, efficient photoinduced electron transfer from MoS 2 to Ti 3 C 2, and enhanced C–C coupling, enabling selective C 2 product formation. This work highlights electron-rich MXene–MoS 2 architectures as a promising photocatalyst platform for solar-driven CO 2 conversion to value-added chemicals.