CoTCPP integrates with BiOBr microspheres for improved solar-driven CO2 reduction performance

CO2 photoreduction into carbon-based chemicals has been considered as an appropriate way to alleviate the energy issue and greenhouse effect. Herein, the 5, 10, 15, 20-tetra (4-carboxyphenyl) porphyrin cobalt (II) (CoTCPP) has been integrated with BiOBr microspheres and formed the CoTCPP/BiOBr composite. The as-prepared CoTCPP/BiOBr-2 composite shows optimized photocatalytic performance for CO2 conversion into CO and CH4 upon irradiation with 300 W Xe lamp, which is 2.03 and 2.58 times compared to that of BiOBr, respectively. The introduced CoTCPP significantly enhanced light absorption properties, promoted rapid separation of photogenerated carriers and boosted the chemisorption of CO2 molecules. The metal Co2+ at the center of the porphyrin molecules also acts as adsorption center for CO2 molecules, accelerating the CO2 conversion into CO and CH4. The possible mechanism of CO2 photoreduction was explored by in-situ FT-IR spectra. This work offers a new possibility for the preparation of advanced photocatalysts.