Impregnation of porous TiO2/ZnO into MCM-41 synthesized from coal fly ash for enhanced photocatalytic activity of TiO2/ZnO@MCM-41 composites in methylene blue removal
Ardi Lukman Hakim, Inzus Etika Sari, Bunga Jasmine Nur Sabrina, Zanna Allia Nurkhalizah, Ecce Kamila Ajeng Zahabiya, Aditya Nur Hidayat, Dety Oktavia Sulistiono, R. Nida Sopiah, Yuly Kusumawati, Ratna Ediati
Abstract
MCM-41 was synthesized from coal fly ash and used as a support for TiO₂/ZnO nanoparticles in methylene blue removal. The composite was prepared using alkali fusion and hydrothermal methods, yielding MCM-41 with a surface area of 1013.73 m 2 /g, which decreased to 457.81 m 2 /g upon TiO 2 /ZnO impregnation. Characterization confirmed the hexagonal mesoporous structure, uniform dispersion of TiO 2 /ZnO, and enhanced light absorption. Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS) results revealed a band gap reduction from 3.22 eV (TZ) to 2.77 eV (TZM), improving photocatalytic activity under UV and visible light irradiation. The 35TiO 2 /65ZnO@MCM-41 composite achieved 99.21% MB degradation in 140 min.