Enhanced CO2 photoreduction by a graphene–porphyrin metal–organic framework under visible light irradiation

Abstract

A photocatalyst consisting of a porphyrin-based metal–organic framework (Al/PMOF) and amine-functionalized graphene (NH₂-rGO) has been designed to reduce CO₂. The structure of the hybrid MOF is investigated as a function of weight percentage of NH₂-rGO added to the Al-PMOF. Also, the graphene-based MOF significantly enhances CO₂ photoreduction compared with the Al-PMOF and the porphyrin ligand. This type of photocatalyst exhibits excellent visible light-driven CO₂ to formate (HCOO⁻) formation. The formate evolution rate on NH₂-rGO (5 wt%)/Al-PMOF is 685.6 μmol g_cat.⁻¹ h⁻¹ with almost 100% selectivity in the presence of TEOA as the sacrificial agent and hydrogen source, which is the highest value compared to those reported in other studies.