Enhanced photocatalytic efficiency of a novel GO/Bi2SO5/AgBr ternary heterojunction for the degradation of tetracycline and rhodamine B
Adewumi Olufemi Oluwole, Tunde L. Yusuf, Shepherd M. Tichapondwa, Michael O. Daramola, Samuel A. Iwarere
Abstract
Water contamination by pharmaceuticals and organic dyes requires advanced photocatalysts to degrade these pollutants effectively. This study used an in-situ precipitation method to synthesize a novel GO/Bi 2 SiO 5 /AgBr heterojunction photocatalyst and thoroughly analysed it for its structure, optical properties, and photocatalytic performance. Characterization techniques confirmed the successful integration of GO, Bi 2 SiO 5 , and AgBr, with BET analysis showing a significant surface area increase from 20.50 m 2 /g to 47.44 m 2 /g. Incorporating GO and AgBr extended visible-light absorption and improved charge separation, as demonstrated by UV-Vis DRS, PL spectra, EIS, and Mott-Schottky measurements. As a result, the photocatalyst achieved high degradation efficiencies of 95.83 % for tetracycline in 60 min and 97.02 % for Rhodamine B in 30 min under visible light. This improvement is attributed to the surface plasmon resonance (SPR) effect of Ag in AgBr and the electron-accepting ability of GO, which enhances charge transfer. Additionally, the photocatalyst showed excellent stability and reusability over five cycles. Quenching experiments confirmed that h⁺ and •O 2 ⁻ radicals were key in pollutant degradation. This study provides a promising strategy for designing efficient, visible-light-driven photocatalysts for sustainable water treatment. • Heterojunction composites of GO/Bi 2 SiO 5/ AgBr synthesized via in-situ precipitation. • GO/Bi 2 SiO 5 /AgBr composites achieved ∼96 % tetracycline degradation in 60 minutes. • 97 % Rhodamine B degradation in 30 minutes was achieved with optimal performance. • Material maintained stability after five cycle runs. • Scavenging experiment shows h + and •O 2 – are dominant reactive species for degradation.