Achieving high carrier separation over Bi₄O₅I₂through Ni doping for improved photocatalytic CO₂reduction

Photocatalytic CO₂reduction 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 Bi₄O₅I₂photocatalyst is successfully fabricated using a one-pot hydrothermal method. A few doping levels appear in the energy band of Bi₄O₅I₂after 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 CH₄(6.2 and 1.9μmol g^-1h^-1) is obtained over the optimized Bi₄O₅I₂-Ni15, which is approximately 2.1 and 3.8 times superior to pure Bi₄O₅I₂, respectively. This work may serve as a model for the subsequent research of Bi-based photocatalysts to implement high-performance CO₂photoreduction.