Photocatalytic degradation of methylene blue by UV‐assistant TiO 2 and natural sericite composites

BACKGROUND In order to prepare an environmental‐friendly photocatalyst, natural mineral sericite is used as the substrate of photocatalysts. In this study, the TiO 2 ‐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 TiO 2 . The prepared composites are characterized by XRD, Raman, FTIR, UV‐vis, SEM, and BETanalysis. The effects of the molecular ratio of TiO 2 to sericite and the calcination temperature are also examined. RESULTS Sericite is not only served as a substrate for nano‐sized TiO 2 to fabricate the micro‐sized composite materials but also affect the formation of different crystalliniteTiO 2 . The characteristic results show that the addition of sericite can stabilize the crystal phase of TiO 2 ; therefore, the sericite can maintain the crystalline anatase of TiO 2 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 TiO 2 ‐sericite composite materials. It indicates that the synergetic effect of TiO 2 ‐sericite composites can facilitate the photocatalytic degradation of TiO 2 accompanied by the initial adsorption of methylene blue by sericite. Based on the presence of various radicals, including ·OH, ·O 2 − , and 1 O 2 , the mechanism of photocatalytic degradation of methylene blue via TiO 2 ‐sericite composites are successfully proposed. CONCLUSION The excellent activity reveals that TiO 2 ‐sericite composites are with potential employed as ecological‐friendly photocatalysts in the degradation of pollutants. © 2020 Society of Chemical Industry