Synthesis and optimization of silver-modified BiOCl/CuBi2O4 heterostructure composite as an efficient visible light photocatalyst against reactive green 5 and turquoise blue dyes.

Abstract

Reactive green 5 (RG 5) and turquoise blue (TB), widely used dyes, pose significant risks to water sources and human health, underscoring the need for effective removal techniques. A more environmentally sustainable approach is heterogeneous photocatalysis, which utilizes semiconductors. However, enhancing the efficacy of photocatalysts remains a challenge. This research aims to develop a potential Bismuth oxychloride (BOC) heterojunction with copper bismuth oxide (CBO) through a hydrothermal method, followed by treatment with silver décor (Ag@BOC/CBO) to enhance its properties for the environmental remediation of RG 5 and TB dyes. The synthesized composites were analyzed using DLS, UV-visible spectroscopy, SEM/EDX, FT-IR, XRD, AAS, and PL techniques. The results indicated that the Ag@BOC/CBO has a z-average of 140 ± 5 nm, a band gap of 2.5 eV, a hierarchical morphology, and tetragonal structures. The Ag@BOC/CBO composite achieved a 5.4% improvement in RG 5 degradation efficacy (98.4%) at pH = 4, with a catalyst concentration of 20 mg/L, dye concentration, and contact exposure of 20 mg L^-1 for 60 min, and a 6.5% increase for TB (99.3%) at pH = 5, with a catalyst concentration of 20 mg L^-1, dye concentration, and contact exposure of 20 mg L^-1 for 60 min. The effective breakdown of dyes into non-toxic substances was confirmed through FT-IR analysis. Kinetic investigations revealed that the Behnajady-Modirshahla-Ghanbery (BMG) model effectively fits the experimental data. The Ag@BOC/CBO demonstrated strong recyclability after five cycles of RG 5 and TB dye degradation while also exhibiting effective broad-spectrum antibacterial activity against E. coli and S. aureus, emphasizing its potential as a photocatalytic material for the oxidation of organic contaminants in water to enhance environmental protection.