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 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, boosting the CO₂ convert 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 advance photocatalysts.