Anchored Cu(II) tetra(4-carboxylphenyl)porphyrin to P25 (TiO2) for efficient photocatalytic ability in CO2 reduction

The exploration of photocatalysts used in converting CO2 into applicable organic products is of significant importance for addressing the universal problems of both global warming and energy shortage. In this work, the sensitizer Cu(II) tetra(4-carboxylphenyl)porphyrin (CuTCPP) was successfully combined with hydroxylated commercial P25 (TiO2) by hydrothermal treatment (denoted as P25(m)). The as-prepared composite CuTCPP/P25(m) shows photocatalytic activity for CO2 reduction to give methane under UV-vis irradiation. The characterizations entailed in our work not only confirm the effective combination of the composite, but exhibit a stronger light absorption capability than P25(m). During the photocatalytic evaluation, the photocatalytic system employing 0.5% CuTCPP/P25(m) (CuTCPP account for 0.5% in the total amount) engendered approximately 46 times higher methane than generated by P25(m) alone. This impressive amelioration can be attributed to a strengthened capability of CuTCPP/P25(m) in light absorption and enhanced separation efficiency of photo-induce electrons and holes.