Copper porphyrin modified BiOBr/BiSBr for efficient CO photoreduction.

The insufficient solar light response ability of the photocatalyst, rapid recombination of interface charges, and lack of active sites significantly inhibit the efficiency of photocatalytic CO reduction. Addressing these challenges simultaneously is a very challenging task. Herein, an interface engineering coupled surface polarization strategy is proposed to optimize the CO photoreduction performance. The copper tetracarboxyphenylporphyrin (CuTCPP) modified BiOBr/BiSBr (BBS) heterostructure was developed. The built-in electric field formed between BiOBr and BiSBr interfaces induces the effective interfacial charge separation, while the surface polarization of CuTCPP induces the transfer of electrons from the conduction band (CB) of BBS to the CB of CuTCPP. Benefiting from this unique configuration and abundant active sites in CuTCPP, greatly improved photocatalytic CO reduction performance can be realized. Without adding cocatalysts and sacrificial agents, the optimized CO generation performance of CuTCPP-BiOBr/BiSBr (BBS-CT) is 3.5 times higher than that of BBS. This work provides valuable insights of interface engineering coupled surface polarization strategy for collaborative improve the photocatalytic CO reduction performance.