Bi₂O₄/Cu₂O based Visible-Light Responsive Z-Scheme Photocatalyst for Bisphenol A Degradation: Experimental Validation and DFT Analysis

Bisphenol A (BPA) is a well-known Endocrine Disruptor, showing substantial carcinogenic effects on human health and is abundantly found in wastewater discharged from epoxy resins. In this research, a visible light active photocatalyst Bi₂O₄ (BC0) is synthesized via hydrothermal technique and doped with Cu₂O (BCx, x = 0.5, 1, 1.5, & 2) via ultrasonic treatment. The composite is characterized by X-ray diffractometry, Scanning Electron Microscope (SEM), diffuse reflectance spectroscopy (DRS) to analyze the crystal structure, surface morphology and light absorption characteristics respectively. Photo degradation experiments revealed that BC1 composite is able to degrade BPA up to 99.4% within half an hour time. And this is achieved when photocatalytic experiments are performed under monochromatic blue light. Moreover, the photocatalytic activity reduced to 75% over five consecutive cycles, showing its great recycling potential. The mechanism proposed by the scavenging experiments and supported via density functional theory simulations indicated that the degradation of BPA is mainly carried out by the photo-induced holes accompanied by the superoxide radical. Given the high cost of artificial light sources (i.e. Hg-Xe lamps), the proposed photocatalyst seems to be highly suitable for decomposing emerging contaminants in impaired waters.