2D/2D BiOBr/(001)-TiO2 heterojunction toward enhanced photocatalytic degradation activity of Rhodamine B

Highlights: • Novel BiOBr/(001)-TiO₂ composites were synthesized through the in-situ construction method. • 2D/2D heterojunction facilitates the separation of photogenerated carriers. • The BiOBr/(001)-TiO₂ (TB-10) displays a superior photocatalytic performance for RhB degradation under Xenon lamp and mercury lamp. • The photocatalytic mechanism is proposed and the superoxide radicals anions (·O₂^-) the main reactive species for RhB degradation. -- Abstract: Developing highly active photocatalyst to degrade organic pollutants is a green strategy to deal with the environmental crisis. Herein, the novel BiOBr/(001)-TiO₂ (TB-x) composites were synthesized via the in-situ construction method. The crystal structure, morphological structure, energy band structure and photoelectrochemical properties of TB-x were characterized, and the results show that the 2D/2D structure has a significant improvement in photo-generated carrier separation and visible light utilization. The optimal Rhodamine B (RhB) degradation reaction rate of TB-10 is 3.4 times and 2.1 times higher than pure (001)-TiO₂ under Xenon lamp and Mercury lamp (500 W), respectively. Meanwhile, the TB-10 displays an excellent cycling performance during photocatalytic reaction. Based on free radical trapping and the electron paramagnetic resonance (EPR) experiments, the pivotal active group is the superoxide radicals anions (·O₂^-) to degrade RhB. This study offers a conception for advancing the application of TB-x photocatalyst in environmental protection.