Owing to polluted water remediation, semiconductor nano photocatalysis has been considered a promising methodology. However, low reaction rates and high electron-hole recombination have impeded their large-scale applications. Therefore, heterogeneous nano photocatalysts are required for promoting their functional applications. Here, sol-gel-based mesoporous titania nanoparticles (TNPs) and silica-titania nanocomposite (STNC) are synthesized and supported with CdTe (CdTe/STNC) for photocatalytic applications. Vapor pressure scanning electron microscopy (VPSEM) exhibited the porous and colonial nanostructure of CdTe supported STNC catalyst. The high-resolution transmission electron microscopy (HRTEM) possessed a spherical morphology with particle size 5.6 nm of TNPs, 2.6 nm of STNC, and 2.1 nm of CdTe/STNC. Moreover, the CdTe/STNC catalyst exhibited a large surface area (S_BET) ∼ 410 m²/g and pore size distribution ∼ 1.8 nm. The CdTe/STNC exhibited high photocatalytic activity with methylene blue degradation of 95% (k = 0.01 min⁻¹) after 180 min of ultraviolet radiation.