Triple-mechanism driven Fe-doped n-n hetero-architecture of Pr6O11-MoO3 decorated g-C3N4 for doxycycline degradation and bacterial photoinactivation

Photocatalysis is a clean technology that can be applied to water treatment processes. In this study, we have constructed n-n heterojunction between Fe-doped Pr6O11-MoO3 and g-C3N4 with a flower-on-sheet morphology (Fe/Pr6O11-MoO3@g-C3N4 NCs). The fabricated nanomaterials were characterized using XRD, XPS, SEM, TEM, SAED, EDX, elemental mapping, PL, DRS, BET, EIS and ESR. The photogenerated charge carriers were produced through three routes - internal electric field caused by n-n heterojunction, dynamic cycling of Fe3+/Fe4+ and Pr3+/Pr4+ metal-oxidation states due to photo-Fenton processes, and the interstitial defect states caused by Fe doping. Interestingly, 30-FPMG NCs attained 98% doxycycline degradation in 280 min and 95% S. epidermis bacterial photoinactivation at 50 mg/L dosage. Here, OH was the primary ROS involved in the photocatalytic process. The effects of NPs dosage, drug concentration, pH and ions were tested. The stability was examined for six consecutive cycles. The photodegradation intermediates were predicted using GC–MS and ECOSAR software was used to assess their toxicity.