Novel magnetic separable BiOBr@Fe3O4 p-n heterostructure with highly efficient photocatalytic property toward organic pollutants

Abstract

In this work, by considering good photocatalytic activity and p-type property but insufficient visible light absorbing property of BiOBr and excellent light absorption, n-type property of Fe3O4 that has poor photocatalytic property due to fast recombination of charge carriers having narrow bandgap, a solar light-active BiOBr@Fe3O4 p-n heterostructure was designed and synthesized for the first time using a versatile chemical precipitation method, combining the p-type BiOBr with the n-type Fe3O4. The developed photocatalyst underwent comprehensive investigation using various high-precision techniques. Its photocatalytic properties were assessed for the photodegradation of organic contaminants, such as Congo red (CR) and rhodamine B (Rh B), under solar light irradiation. The degree of mineralization of these pollutants by the BiOBr@Fe3O4 p-n heterostructure during photodegradation was also evaluated. Additionally, the photodegradation pathway was examined using LC-MS, and a possible mechanism were proposed. The findings reveal that the developed BiOBr@Fe3O4 p-n heterostructure exhibited exceptional photocatalytic performance, degrading 100 % and 81 % of Rh B and CR, respectively. Kinetic findings also indicate that the rate of photodegradations of the pollutants by the BiOBr@Fe3O4 heterostructure is approximately 7.2 and 3.4 times higher than that of pure Fe3O4 for the degradation of CR and Rh B, respectively. Besides, the developed heterojunction exhibited better photocatalytic performance than existing photocatalysts for photodegradation of CR and Rh B. The total organic carbon content (TOC) analysis further demonstrates the exceptional mineralization properties of the fabricated photocatalyst toward the pollutants. Therefore, the developed BiOBr@Fe3O4 p-n heterostructure shows promise in the treatment of these organic pollutants, contributing significantly to environmental remediation, particularly in photocatalysis.