BACKGROUND In order to prepare an environmental‐friendly photocatalyst, natural mineral sericite is used as the substrate of photocatalysts. In this study, the TiO2‐sericite composite materials are synthesized by a facile sol‐gel process, followed via a calcination treatment that can improve the crystallinity of the nano‐sized TiO2. The prepared composites are characterized by XRD, Raman, FTIR, UV‐vis, SEM, and BETanalysis. The effects of the molecular ratio of TiO2 to sericite and the calcination temperature are also examined. RESULTS Sericite is not only served as a substrate for nano‐sized TiO2 to fabricate the micro‐sized composite materials but also affect the formation of different crystalliniteTiO2. The characteristic results show that the addition of sericite can stabilize the crystal phase of TiO2; therefore, the sericite can maintain the crystalline anatase of TiO2 even after the calcination at 700 °C and 900 °C. Accordingly, the adsorption test and the photocatalytic degradation of methylene blue are conducted to verify the photocatalytic performance of the TiO2‐sericite composite materials. It indicates that the synergetic effect of TiO2‐sericite composites can facilitate the photocatalytic degradation of TiO2 accompanied by the initial adsorption of methylene blue by sericite. Based on the presence of various radicals, including ·OH, ·O2−, and 1O2, the mechanism of photocatalytic degradation of methylene blue via TiO2‐sericite composites are successfully proposed. CONCLUSION The excellent activity reveals that TiO2‐sericite composites are with potential employed as ecological‐friendly photocatalysts in the degradation of pollutants. © 2020 Society of Chemical Industry