Photocatalytic carbon dioxide reduction to value-added hydrocarbons products

The photocatalytic reduction of CO 2 into multi-carbon (C 2+ ) products using solar energy is a promising yet complex area of research. Compared to single-carbon products (C 1 ), C 2+ compounds have higher added value and broader application potential. This review focuses on various catalyst modification strategies—such as morphology regulation, doping, and bimetallic synergy—aimed at enhancing the efficiency of multi-carbon product formation. Special emphasis is placed on the mechanisms of carbon-carbon coupling reactions, which play a critical role in generating C 2+ products. Additionally, the pathways for producing different C 2+ products, especially ethylene and ethanol, are summarized to offer insights into their formation. This review provides a detailed examination of catalyst design, product regulation, and reaction pathways, aiming to facilitate further research and exploration in the field. • Elucidation of core C–C coupling mechanisms driving selective photocatalytic CO₂ reduction to multicarbon (C₂ + ) products. • Catalyst platforms and strategies: light absorption, charge separation, active-site exposure, coupling barriers. • Integration of in situ XANES/EXAFS, FT-IR, Raman, and 13 C-NMR techniques to map intermediates and reaction mechanisms.