Development of a crystalline n-AgBr/p-NiO binary heterojunction for photocatalytic degradation of organic contaminants with accompanying mineralization, adsorption, and antimicrobial studies†

Abstract

A highly effective and unique AgBr–NiO binary heterojunction was developed using an effective one-pot sol–gel method. The physicochemical properties of the produced materials were carefully examined using analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis-DRS), Fourier transform infrared spectroscopy (FTIR), and photoluminescence (PL). The mesoporous nature and high surface properties of AgBr–NiO were revealed by the BET analysis. The AgBr–NiO composite showed greater photocatalytic degradation efficiency than bare AgBr and NiO when exposed to visible light for the colored anionic dye rhodamine B (RhB) and bisphenol A (BPA), a colorless endocrine-disrupting contaminant (EDC), resulting in high photocatalytic activity for the degradation of RhB (97.6% in 11 min) and BPA (85% in 120 min). Additionally, a notable decrease in TOC over time was observed under similar reaction conditions in the photo-mineralization examination of both model pollutants. Trapping tests were conducted to determine which reactive oxygen species (ROS) were involved in the degradation process. A plausible Z-scheme mechanism for this n–p heterojunction was proposed to explain the formation of e⁻/h⁺ pairs induced by visible light. The proposed work facilitates the development of a recyclable photocatalyst characterized by high biological activity and low toxicity.