In Situ Synthesis of TiO₂‑Doped Mesoporous Silica from Coal Fly Ash for the Photocatalytic Degradation of Dyes

TiO₂-doped mesoporous silica (TDMS) was synthesized in situ from coal fly ash for photocatalytic degradation of organic dyes. The prepared TDMS is mainly composed of SiO₂ and anatase TiO₂ and has a sponge-like mesoporous structure with a high specific surface area of 297 m²/g. In photocatalytic experiments, TDMS shows good performance in the removal of dyes. The decoloration rates of both rhodamine B and acid orange II reached 99.9% within 6 h at a TDMS dosage of 4 g/L, and the total organic carbon (TOC) removal efficiency reached 90.3 and 84.1%, respectively. Furthermore, whereas the dye decoloration rate of TDMS is comparable to that of commercial TiO₂ (anatase), it shows much better TOC removal efficiency. The results indicate that TDMS can be a potential and low-cost photocatalyst for treating water polluted with dyes.