Abstract
This study presents a facile one-pot synthesis method to fabricate BiFeO(3)-Bi(25)FeO(40)-Bi(2)O(3) heterojunction photocatalysts with controllable compositions and pure phases. Three different binary heterojunctions (BiFeO(3)/Bi(25)FeO(40), BiFeO(3)/Bi(2)O(3), and Bi(25)FeO(40)/Bi(2)O(3)) and a ternary BiFeO(3)/Bi(25)FeO(40)/Bi(2)O(3) 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 BiFeO(3)/Bi(25)FeO(40) 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 BiFeO(3)/Bi(25)FeO(40) was even over twice that of BiFeO(3) and Bi(25)FeO(40), and four times higher than that of Bi(2)O(3). The enhanced photocatalytic activity of the BiFeO(3)/Bi(25)FeO(40) 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 BiFeO(3)-Bi(25)FeO(40)-Bi(2)O(3) heterojunction materials, position them as highly promising candidates for applications in environmental remediation and solar energy conversion.