Room Temperature Synthesis of Visible Light Active PANI/BiOBr <i>Z</i> ‐Scheme Heterojunction for the Photocatalytic Degradation of Rhodamine B

Abstract Photocatalytic degradation using freely available sun light is one of the crucial approaches in remediation of persistent organic pollutants, such as rhodamine B (RhB). Developing effective photocatalysts is one of the key challenges in meeting such sustainable development goals. In this study, a series of binary composite photocatalysts of bismuth oxybromide (BiOBr) with varying amounts of polyaniline (PANI) were synthesized at room temperature. The nanocomposite, with 9 wt % of PANI (PB‐70) displayed enhanced photocatalytic performance for the degradation of RhB dye when compared to bare PANI and BiOBr, under visible light. The degradation of 20 ppm RhB reached 100% in about 30 min using PB‐70 as the photocatalyst. Moreover, complete mineralization of RhB also could be achieved using PB‐70. Predominant involvement of superoxide ion (•O 2 ─ ) radicals along with lower contributions from holes (h + ) and hydroxyl (•OH) radicals was evident from the scavenger studies. Enhanced photophysical properties of PB‐70 were confirmed, when compared to PANI and BiOBr. Formation of a Z ‐scheme heterojunction between PANI and BiOBr in the PB‐70 was thus, found to be the reason for the enhanced photocatalytic activity.