Quasi-1D/3D Bi2O4/phase-tuned C3N5 type-II heterostructure for the visible-light-driven photocatalytic degradation of resorcinol in wastewater: insights into the inhibitory effects of matrix interferences and phytotoxicity assessment

Abstract

Over the years, resorcinol (RCL) has been used to manufacture various pharmaceuticals and personal care products (PPCPs). Its extensive use in treating skin infections has made it ubiquitous in environmental matrices, raising a global threat owing to its endocrine-disrupting nature. In this regard, a novel quasi-1D/3D Bi₂O₄/PT-C₃N₅ photocatalyst (referred to as BCN hereafter) was synthesized employing a facile hydrothermal technique for the photocatalytic degradation of RCL. Benefiting from the enhanced visible light responsiveness and impeded charge carrier recombination, the as-fabricated BCN-10 (comprising 10% PT-C₃N₅) exhibited 94.3% RCL degradation after 180 min under optimal conditions. The BCN-10 photocatalyst was found to be chemically stable and demonstrated reusability up to 5 cycles with a minimal reduction in degradation efficiency. Thereafter, the impact of other emerging contaminants (ECs) and actual water matrices was analyzed to determine the practical applicability of the photocatalytic system. The charge transfer mechanism in BCN-10 was confirmed to follow a type-II pathway, where O₂˙⁻ and h⁺ were established as the key reactive species promoting RCL degradation. Furthermore, the seed germination assay performed for treated and untreated RCL solutions showcased a germination index (GI) of 82% indicating the treated RCL solution to be non-phytotoxic. This study helps in understanding the creation of heterojunction photocatalysts by using an emerging non-trivalent variant of bismuth oxide and N-rich phase-tuned graphitic carbon nitride for wastewater treatment.