A Simple One-Pot Method for the Synthesis of BiFeO3/Bi25FeO40 Heterojunction for High-Performance Photocatalytic Degradation Applications

Abstract

This study presents a facile one-pot synthesis method to fabricate BiFeO3-Bi25FeO40-Bi2O3 heterojunction photocatalysts with controllable compositions and pure phases. Three different binary heterojunctions (BiFeO3/Bi25FeO40, BiFeO3/Bi2O3, and Bi25FeO40/Bi2O3) and a ternary BiFeO3/Bi25FeO40/Bi2O3 heterojunction were formed, all exhibiting significantly enhanced photocatalytic performance for the degradation of methylene blue (MB) and phenol under visible light irradiation, outperforming the individual compositions. Notably, the BiFeO3/Bi25FeO40 heterojunction achieved the highest degradation efficiency (93.68% and 83.3% for MB and phenol, respectively) as well as excellent stability. Impressively, the phenol degradation efficiency of BiFeO3/Bi25FeO40 was even over twice that of BiFeO3 and Bi25FeO40, and four times higher than that of Bi2O3. The enhanced photocatalytic activity of the BiFeO3/Bi25FeO40 heterojunction is primarily attributed to the advantageous S-scheme band alignments that facilitate efficient charge separation and enhance redox capabilities. While other heterojunctions also exhibited improved MB and phenol degradation efficiency, each unique combination of materials led to distinct electronic structures and diverse reaction mechanisms. The simplicity and scalability of the synthesis method, combined with the remarkable photocatalytic performance of these BiFeO3-Bi25FeO40-Bi2O3 heterojunction materials, position them as highly promising candidates for applications in environmental remediation and solar energy conversion.