Progress in heterostructures for photoelectrocatalytic reduction of carbon dioxide into fuels and value-added products

Carbon capture and utilization (CCU) technology offers a sustainable option to simultaneously address both energy crisis and environmental pollution such as catalytic reduction of carbon dioxide (CO₂) into value-added fuel products (e.g., C₁–C₃). Among diverse CCU strategies, the light-irradiated photoelectrocatalytic (PEC) approach is recognized as a cutting-edge option for efficient CO₂ reduction reaction (RR) through the integration of photocatalysis and electrocatalysis within a one-stage hybridized catalytic system. Therefore, this review is meticulously structured to elucidate the potential utility of advanced composite catalysts (e.g., titanium dioxide, metal-organic frameworks, and organic/miscellaneous heterostructure materials) in PEC-CO₂RR. It also examines the factors and processes governing their PEC-CO₂RR activites in relation to their reduction pathways, electronic structures, charge-carrier dynamics, types of electrolytes, mass transfer, light-adsorption potential, and the viability of active sites. The fundamental principles and working mechanisms of diverse catalytic materials in PEC-CO₂RR are also outlined to help establish the advanced catalytic systems based on performance assessments (e.g., in terms of CO₂ conversion rate, quantum yield, and space-time yield). Overall, this review is expected to deliver the new path for the construction of the next-generation PEC-CO₂RR systems that are upscalable, stable, and reusable with enhanced catalytic activity.