A P-doped BiOBr nanosheet for enhanced photocatalytic CO2 reduction efficiency

Abstract

The photocatalytic CO2 reduction efficiency of BiOBr is constrained by its insufficient ability to effectively absorb visible light, as well as its rapid photogenerated electron-hole complexation. Modulating the band gap and charge transfer kinetics of photocatalysts through heteroatom doping is an effective solution. P-doped BiOBr photocatalysts were synthesized through a one-step hydrothermal method to promote the photocatalytic reduction of CO2 in this investigation. The photocatalytic reduction of CO2 to CO using an 8 % P-BiOBr catalyst achieved a rate of 9.13 µmolg−1h−1, which is 3.3 times greater than that observed with the pure BiOBr catalyst. XPS, UV-Vis DRS and Mott-Schottky analyses revealed that P-BiOBr had a narrower forbidden bandwidth and a more negative conduction band, which improved the absorption of visible light and the reduction ability of CO2. Furthermore, The transient photocurrent response, electrochemical impedance spectroscopy (EIS), and photoluminescence (PL) spectra signify that the doping of phosphorus (P) enhances the separation and mobility of the carriers generated by light in BiOBr. This research offers a straightforward approach for doping with P, which enhances photocatalytic reduction of CO2 by semiconductor.