In Situ Construction of CuTCPP/Bi 4 O 5 Br 2 Hybrids for Improved Photocatalytic CO 2 and Cr(VI) Reduction.

Global warming and heavy metal pollution pose tremendous challenges to human development, and photocatalysis is considered to be an effective strategy to solve these problems. Herein, copper(II) tetra (4-carboxyphenyl) porphyrin (CuTCPP) molecules were successfully in situ loaded onto Bi 4 O 5 Br 2 by a hydrothermal approach. A series of experimental results show that the light absorption capacity and photogenerated carrier separation efficiency were synchronously enhanced after the construction of CuTCPP/Bi 4 O 5 Br 2 composites. Hence, the as-prepared composites possess significantly improved photocatalytic ability for both CO 2 and Cr(VI) reduction. Specifically, CuTCPP/Bi 4 O 5 Br 2 -2 achieves a CO generation rate of 17.14 μmol g -1 under 5 h irradiation, which is twice as high as that of Bi 4 O 5 Br 2 (8.57 μmol g -1 ). Besides, the optimized CuTCPP/Bi 4 O 5 Br 2 -2 also exhibits a removal rate of 61.87% for Cr(VI) within 100 min under irradiation. Furthermore, the mechanism of CO 2 and Cr(VI) photoreduction was explored by in situ Fourier transform infrared spectroscopy and capture experiments, respectively. This work can be a reference toward the construction of photocatalysts with high activity for solar energy conversion.