Synthesis of Bi2O3/Sb2S3 Nanocomposite for Photocatalytic Degradation of Rhodamine-B and Tetracycline

Abstract

The application of photocatalytic decomposition has garnered significant interest as a viable approach to mitigate water contamination and environmental pollution. In the face of expanding industrial development and rapid population increase, water pollution poses a grave threat to the ecosystem and human well-being. This study employs a hydrothermal technique to synthesize the photocatalyst by varying the mole ratios of Bi2O3 and Sb2S3. Loading Sb2S3 onto Bi2O3 enables broad-spectrum solar light absorption, efficient segregation of charges, and enhanced surface area. The characteristics of the elements were thoroughly examined through XRD and XPS techniques, enabling analysis of the crystal structure, chemical valence, and surface chemical makeup. The formation of smaller Sb2S3 nano-rods, effectively deposited onto bigger Bi2O3 nano-rods, was visually confirmed via SEM and TEM images. The EDS spectra evidenced the even dispersion of elements. PL and UV–DRS spectroscopy provided evidence of low charge recombination and a narrow band gap, indicating appropriate traits for photocatalysis. Furthermore, BET analysis revealed the photocatalyst's extensive surface area and mesoporous nature. Remarkable decomposition efficiencies were achieved, with a 98.2% degradation rate (rate constant = 0.03149 min-1) observed for Rhodamine-B and a 91.5% degradation rate (rate constant = 0.01749 min-1) achieved for Tetracycline. These impressive results were obtained using 0.3 g/L of the 13BOSBS photocatalyst under sunlight illumination for 120 min. Reusability studies confirmed the catalyst's impressive stability, with approximately 74.4% degradation of Rh-B maintained even after seven consecutive runs. Scavenger experiments highlighted the crucial role of •OH radicals in the photodecomposition mechanism. For the RhB dye, the 13BOSBS catalyst demonstrated remarkable 90.2% and 85% reductions in COD and TOC, respectively. The commercially available TC powder substantially reduced 84% in COD and 80% in TOC. Owing to its excellent attributes and simple synthesis method, the fabricated heterojunction holds great potential for ecosystem rehabilitation.