Carbon dioxide reduction to methanol with water using visible light-activated organic photocatalysts selected based on DFT calculations

Photocatalytic reduction of CO 2 is a viable approach to achieve carbon neutrality. In this study, density functional theory (DFT) calculations predicted that polycyclic aromatic hydrocarbons, picene, 5,8-dicyanopicene (CN-picene), 2,7-dicyanopyrene (CN-pyrene), and 9,10-dicyanoanthracene (CN-anthracene), as photocatalysts for CO 2 reduction driven by UV or visible light exposure. Notably, CN-anthracene was predicted to be the most effective photocatalyst under visible light irradiation. Therefore, photocatalytic performance of CN-anthracene in converting CO 2 into methanol by visible light exposure in an aqueous medium was examined. Methanol production was observed upon irradiation CN-anthracene with visible light, involving CO 2 and H 2 O. Reusability experiments showed that CN-anthracene can facilitate stable methanol production even after three cycles of photocatalytic activity. Photocatalytic reduction of CO 2 performed using D 2 O, instead of H 2 O, confirmed that the produced methanol results from water, without involving the decomposition of the photocatalyst. In conclusion, CN-anthracene demonstrates high efficiency and stability as a photocatalyst for CO 2 reduction under visible light irradiation. • Picene photocatalyst reduce CO 2 to CH 3 OH under UV light irradiation • CN-picene, as a picene derivative, reduce CO 2 even under visible light irradiation • CN-anthracene effectively reduce CO 2 to CH 3 OH under visible light irradiation • Hydrogen from water is used to produce CH 3 OH from CO 2