Achieving high carrier separation over Bi4O5I2 through Ni doping for improved photocatalytic CO2 reduction

Abstract Photocatalytic CO 2 reduction is considered to be an appealing way of alleviating environmental pollution and energy shortages simultaneously under mild condition. However, the activity is greatly limited by the poor separation of the photogenerated carriers. Ion doping is a feasible strategy to facilitate the charge transfer. In this work, Ni-doped Bi 4 O 5 I 2 photocatalyst is successfully fabricated using a one-pot hydrothermal method. A few doping levels appear in the energy band of Bi 4 O 5 I 2 after Ni doping, which are used as springboards for electrons transition, thus promoting photoexcited electrons and holes separation. As a consequence, a remarkably enhanced yield of CO and CH 4 (6.2 and 1.9 μ mol g −1 h −1 ) is obtained over the optimized Bi 4 O 5 I 2 -Ni15, which is approximately 2.1 and 3.8 times superior to pure Bi 4 O 5 I 2 , respectively. This work may serve as a model for the subsequent research of Bi-based photocatalysts to implement high-performance CO 2 photoreduction.