Synthesis and characterization of cadmium sulfide and titania photocatalysts supported on mesoporous silica for optimized dye degradation under visible light

This research presents a new and improved photocatalyst based on the synergistic effect of three components, CdS, TiO₂, and MCM-41, applying statistical techniques to fine-tune degradation parameters for efficient Methylene Blue (MB) degradation. By creating a library of CdS/TiO₂ nanoparticles systematically loaded onto the mesoporous structure of MCM-41, with different loading percentages (5, 10, 15, 20, and 25% w/w), nanocomposites with high surface area and maximized optical properties were designed and analyzed using material characterization techniques including XRD, FTIR, XPS, UV-Vis DRS, TEM, FESEM, EDS, PL, and BET. Ideal performance was achieved from CdS/TiO₂/MCM-41 (CTM) with a 15% w/w loading, which shows high photocatalytic performance at a neutral pH, reaching 45.6% MB degradation with only two 60-W lamps in 30 min. Furthermore, TOC analyses confirmed the effective degradation of MB and its intermediate. The reduction of the TOC (63%, 90 min), indicating successful mineralization of the pollutant. Response surface methodology was used to identify key factors that boost degradation performance, including pH, airflow, and photocatalyst concentration. This model, with a correlation coefficient of R² = 0.991 and a precision of 47.65, confirmed CTM's potential as a scalable solution for wastewater treatment and pollution control.