Reinforced AgFeO2-Bi4TaO8Cl p-n heterojunction with facet-assisted photocarrier separation for boosting photocatalytic degradation of ofloxacin

[Display omitted] •A novel 0D/2D dot-on-plate AgFeO2-Bi4TaO8Cl p-n heterojunction was constructed.•AgFeO2-Bi4TaO8Cl exhibits superior photocatalytic degradation activity towards ofloxacin antibiotic.•Facet-assisted charge separation was identified for n-type Bi4TaO8Cl.•The p-n heterojunction enhances light absorption and spatial charge separation.•The main reactive species for the photocatalytic mechanism were discussed. Accelerating charge transfer is believed to be a feasible strategy to improve the photocatalytic performance of heterojunctions. Herein, a novel dot-on-plate heterojunction was designed and constructed by anchoring p-type AgFeO2 nanoparticles on the surface of n-type Bi4TaO8Cl nanosheets via a facile ultrasound-assisted deposition combined with calcination process, which endows an intimate p-n heterointerface. The Bi4TaO8Cl nanosheets with mainly exposed {001} and {110} facets show unique facet-assisted charge carrier separation. After building up the p-n heterojunction, the established internal electric field further promotes the separation and migration of photogenerated charge carriers, and hinders the charge carrier backflow for recombination at the heterointerface. As a result, compared to pure AgFeO2 and Bi4TaO8Cl, AgFeO2-Bi4TaO8Cl p-n heterojunction exhibits greatly enhanced activity in the photocatalytic degradation of ofloxacin (OFL) antibiotic under visible light irradiation. This work could provide meaningful insights into the design of efficient p-n heterojunction for steering interfacial charge flow and applying in photocatalytic environmental remediation.