Cu doping induced lattice distortion and oxygen vacancy formation in PbBiO2Br: Band structure modulation enhances photocatalytic nitrogen fixation and pollutant degradation performance

Abstract

Photocatalytic nitrogen fixation has emerged as a sustainable alternative for ammonia synthesis, playing a crucial role in alleviating energy shortages and environmental pollution. In this study, PbBiO 2 Br was applied to photocatalytic nitrogen fixation for the first time, and its photocatalytic performance was effectively enhanced through Cu doping. The catalyst was synthesized via a simple reduction method, and its morphology, structure, and physicochemical properties were systematically investigated using various characterization techniques and density functional theory calculations. The results revealed that the incorporation of Cu 2+ partially replaced Pb 2+ , inducing lattice distortion in PbBiO 2 Br, promoting the formation of oxygen vacancies, and modifying its electronic band structure. Specifically, Cu doping led to a slight bandgap narrowing, a reduction in work function, and a significant upward shift in the conduction band position. These changes enhanced light absorption, facilitated charge carrier migration and separation, and improved the reduction ability of photogenerated electrons. Moreover, Cu doping promoted N 2 adsorption and activation. Consequently, the photocatalytic nitrogen fixation performance of Cu-doped PbBiO 2 Br was significantly enhanced, achieving an optimal nitrogen fixation rate of 293 μmol L -1 g -1 h -1 , which is 3.6 times higher than that of pristine PbBiO 2 Br. Additionally, Cu-PbBiO 2 Br also showed good activity in the photocatalytic degradation of RhB, with a degradation rate 4.6 times higher than that of PbBiO 2 Br. This work offers new insights into the application of PbBiO 2 Br in photocatalytic nitrogen fixation and offers valuable guidance for the development of highly efficient nitrogen fixation materials in the future. Cu doping modulates the electronic structure and surface defects of PbBiO 2 Br, which is applied to photocatalytic nitrogen fixation for the first time, achieving significantly enhanced N 2 fixation and pollutant degradation performance. • Cu doping induced lattice distortion, promoted oxygen vacancy formation, and modified the electronic band structure. • Cu doping facilitated N 2 adsorption and activation and improved charge separation efficiency. • Cu-PbBiO 2 Br achieved a 3.6-fold higher nitrogen fixation rate than pristine PbBiO 2 Br. • Cu-PbBiO 2 Br also exhibited a 4.6-fold enhancement in RhB degradation rate over PbBiO 2 Br.