Surfactant-driven modifications to AlFeO3 for degradation of emerging antibiotic contaminants

We show that residues of unused antibiotics Sulfamethoxazole (SMZ) and tetracycline (TC) in wastewater can be treated by photocatalytic degradation. Here, a magnetic photocatalyst known as aluminum ferrite (AlFeO₃) is employed to assess the degradation of SMZ and TC under visible light conditions. The structural and functional properties of co-precipitated AlFeO₃ with four different surfactants are examined. The little-known relevance of surfactant usage in AlFeO₃ synthesis, its characteristics, and its impact on emergent particle morphology for SMZ and TC degradation is reported. The results indicate that the catalyst can completely (100 %) degrade SMZ and TC in ∼60 mins. We propose a distinct degradation pathway for the same. Significantly, AlFeO₃ can decompose TC and SMZ to yield rather small compounds (m/z ∼ 60), thereby showing potential for practical use. Also, the use of different surfactants indicates that surface potential plays a significant role in photocatalytic degradation. Despite the large size and low surface area, AlFeO₃ performed well due to the surface potential of the catalyst. Findings suggest that using bulk catalysts with adjusted surface potentials offers sufficient performance, thereby bypassing the need for nano-sizing and concern about nano-toxicity. Further, the magnetic property of AlFeO₃ facilitates the recovery and reuse of the catalyst post-degradation.