Unlocking solar energy: Photocatalysts design for tuning the CO2 conversion into high-value (C2+) solar fuels

Abstract

The carbon dioxide (CO₂) conversion to useful chemicals is a promising technique to address global environmental issues and ensure a renewable energy supply. Despite the efforts to enhance product yield with different catalysts, most studies focused on improving efficiency with less emphasis on the selectivity of higher hydrocarbon (C₂₊) products. Hence, CO, CH₄, and HCOOH are the commonly obtained products during CO₂ photoreduction according to most literature. C₂₊ hydrocarbons have a higher market value compared to C₁ products. Therefore, research on photocatalytic CO₂-to-C₂₊ conversion has received significant attention in recent years. This review discusses the progress of CO₂-to-C₂₊ photoconversions. First, the insights into CO₂ reduction, kinetics, critical challenges, and underlying mechanisms involved in the conversion of CO₂-to-C₂₊ are highlighted. Further, the progress on strategies such as defect engineering, heteroatom doping, cocatalysts deposition, single or dual-atom catalysts, heterostructured combinations, and morphological modulations to improve the selectivity of CO₂ reduction towards C₂₊ formation has been discussed. Factors affecting the performance of CO₂-to-C₂₊ are discussed throughout, focusing on aspects like the interaction of reactants with the catalyst surface, various reaction conditions, intermediate formation, *C₁ stabilization, and C–C coupling. Finally, a summary and outlook on recent trends in CO₂ utilization are discussed.