Characterization of SBA-16 supported nanocomposites and their evaluation for photocatalytic applications

The removal of synthetic dyes from wastewater is a pressing environmental challenge, as these pollutants are highly persistent, toxic and resistant to conventional treatment methods. Photocatalysis offers a sustainable, energy-efficient solution and the development of stable, high-performance catalysts is critical for practical applications. To this aim, this study reports the synthesis, characterization and photocatalytic performance of MoO3@Fe3O4@SBA-16 nanocomposites for methylene blue (MB) degradation under UV-A irradiation. SBA-16 mesoporous silica was functionalized with Fe3O4 and subsequently impregnated with varying MoO3 loadings (10–30 wt%). Comprehensive characterization (XRD, FTIR, SEM, BET, UV-Vis DRS) confirmed the successful integration of Fe3O4 and MoO3, resulting in enhanced textural properties, light absorption and suppressed charge carrier recombination. Photocatalytic performance was evaluated under a low-power 32 W UV-A lamp at natural pH. Among synthesized catalysts, the 20% MoO3@Fe3O4@SBA-16 composite achieved 94.40% photocatalytic degradation in 120 minutes. Process optimization using central composite design (CCD)-based response surface methodology (RSM) identified reaction time (60–180 min) as the most influential parameter, followed by catalyst dosage (25-75 mg) and dye concentration (10-20 ppm). Predictive modeling with RSM, artificial neural networks (ANN) and adaptive neuro-fuzzy inference system (ANFIS) revealed ANFIS as the most accurate (R2= 0.992, MAE= 0.240). Kinetic analysis confirmed pseudo-first-order behavior, and the catalyst maintained high efficiency over multiple cycles, retaining over 90% of its initial PE% after six consecutive runs (declining from 94.40% in the first cycle to 94.09% in the sixth). These results highlight MoO3@Fe3O4@SBA-16 as a promising, stable and reusable photocatalyst for sustainable wastewater treatment applications.