Photocatalytic degradation of methylene blue by UV‐assistant TiO<sub>2</sub> and natural sericite composites
Chao‐Wei Huang, Min‐Chien Wu
Abstract
Abstract 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