Facile solvothermal synthesis of Exfoliated-Corrugated g-C3N4@BiOBr heterojunction for fast visible light Photocatalyst: A structural and optical study

A novel and versatile strategy to increase the photoreactivity (PR) of catalytic systems is to modulate the coupling between two dimensional (2D) semiconductors. Herein, a 2D heterojunction of graphitic carbon nitride (g-C3N4) and bismuth oxobromide (BiOBr), g-C3N4@BiOBr, was carefully synthesized by a solvothermal method at different molar ratios. The optical, morphological, structural, and electronic properties were characterized for the heterojunction and compared with pure 2D BiOBr and g-C3N4. The photocatalytic degradation kinetics of rhodamine B showed that the molar composition (1:2) of g-C3N4@BiOBr produces the largest activity under visible light. Radical scavenger studies showed that the (1:2) heterojunction in an oxygen-saturated environment induces superoxide and hole radicals that actively participate in the photodegradation, while the contribution of hydroxyl radicals is negligible. The optimized PR derives from the perfect coupling between (0 0 1) crystalline planes of BiOBr with (0 0 2) planes of g-C3N4 as evidenced by HRTEM and XRD. To prove the photocatalytic efficiency, tests were carried out on the degradation of different dyes, their reuse cycles, and the degradation capacity of emerging contaminants, particularly for the antibiotic sulfadiazine, obtaining excellent promising results for the development of future commercial applications for the treatment of wastewater.