POME-derived Ag/Bi2MoO6/TiO2 ternary nanocomposite: Structural design, optical properties, and multifunctional photocatalytic performance

Abstract

The development of visible-light-responsive, multifunctional photocatalysts is critical for advancing solid-state materials for environmental and antimicrobial applications. Conventional Ag/TiO2 photocatalytic systems offer a promising solution for visible-light responsiveness and antimicrobial properties, but often suffer from poor stability and recovery, as well as complex synthesis routes. In this work, a ternary Ag/Bi2MoO6/TiO2 (ABMOT) heterojunction photocatalyst was synthesized via a green, microwave-assisted approach using palm oil mill effluent (POME) as a natural reducing and stabilizing agent, thereby addressing waste valorization alongside material fabrication. Structural, morphological, and optical properties were systematically investigated using FTIR, XRD, PL, XPS, TEM, SEM-EDX, and UV–Vis DRS, thereby confirming the successful formation of a heterojunction and the enhancement of visible-light absorption. The ABMOT nanocomposite achieved 97.2% degradation of oxytetracycline under visible light irradiation at an optimal dosage of 0.6 g/L, attributed to its strong adsorption capacity, pollutant tolerance, and structural stability over four successive cycles. In addition, ABMOT imparted notable antibacterial activity against Escherichia coli and Staphylococcus aureus, demonstrating its multifunctional nature. To overcome the recovery limitations of slurry photocatalysts, ABMOT was immobilized in polyacrylonitrile (PAN) membranes via the phase inversion, resulting in improved hydrophilicity, porosity, water flux, and pollutant rejection. This study presents a sustainable approach to designing multifunctional ABMOT ternary photocatalysts with enhanced optical and physicochemical properties, providing insights into circular-economy-driven solid-state materials for advanced separation and photocatalytic technologies.