Fabrication of copper porphyrin-ruthenium pincer complex coupled polymer/Cs0.33WO3 Z-scheme composite photocatalyst for highly efficient CO2 conversion

Abstract

The photocatalytic system that simulates the principle of photosynthesis is considered one of the most promising technologies for converting CO2 into chemical fuels. Herein, copper tetra(4-carboxyphenyl)porphyrin (CuPor)-ruthenium 2,6-bis(5-amino-benzimidazol-2-yl)pyridine pincer complex (RuN3) coupled polymer (CuPor-RuN3) is in-situ polymerized on hexagonal tungsten bronze Cs0.33WO3 (CsWO) nanoparticles to construct a novel CuPor-RuN3/CsWO composite photocatalyst with cascade charge transfer mechanism, where the inorganic–organic Z-scheme heterojunction at the CuPor-RuN3/CsWO interface and the Z-scheme molecular junction (-[CuPor-RuN3]-) within the polymer facilitate photoexcited electrons transferring from CuPor units to RuN3 ones, and finally enriching on Ru sites for boosting the CO2 reduction reaction (CO2RR). Under visible light irradiation and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole serving as electron donor, the resultant CuPor-RuN3/CsWO delivers average CO/CH4 yields up to 4645/89 μmol g-1h−1, corresponding to an overall photoactivity of 10002 μmol g-1h−1, which is 20 times higher than that of the single polymer. These results provide new ideas for exploring high-performance artificial photosynthesis system to convert CO2 into chemical fuels.