Engineering Z-scheme charge flow in polymeric carbon nitride/BiOBr0.5I0.5 Photocatalyst: Synergistic ROS Cascade for rapid BPA degradation

A direct Z -scheme heterojunction was constructed between carbon nitride and BiOBr 0.5 I 0.5 ultrathin nanosheets. • The optimized composite achieved 84% BPA removal efficiency under visible light irradiation within 40 min. • The internal electric field at the heterointerface drives a direct Z-scheme charge transfer pathway. • The h + , •O 2 − , and •OH were identified as dominant active species via ESR and scavenging experiments. • Enhanced spatial carrier separation and preserved redox ability synergistically boost photocatalytic degradation activity. Bismuth oxyhalide-based solid solutions have excellent visible light absorption and oxidation capabilities, but limited charge separation efficiency hinders their applications. In this study, a Z-scheme heterojunction involved ultrathin polymeric carbon nitride (CN) and BiOBr 0.5 I 0.5 solid solution (BOBI) nanosheets was synthesized for BPA photodegradation. The well-matched energy bands and work function difference between CN and BOBI promote efficient separation and transfer of photogenerated carriers. Meanwhile, CN/BOBI retains the strong reduction capacity of CN and the strong oxidation capacity of BOBI, which is conducive to the generation of more reactive oxygen species (ROS, •OH and •O 2 − ) and holes. Based on these advantages, CN/BOBI exhibits excellent bisphenol A (BPA) removal performance. The optimized CN/BOBI-2 composite achieves an 84% BPA removal efficiency under visible light irradiation. This work establishes a scalable strategy for modulating solid solution photocatalysts via heterojunction engineering, which can be applied to sustainable environmental remediation. Download: Download high-res image (213KB) Download: Download full-size image