Novel BaSnO3/TiO2@HNTs Heterojunction Composites with Highly Enhanced Photocatalytic Activity and Stability

摘要

The novel BaSnO3/TiO2@HNTs photocatalysts were successfully synthesized by co-precipitation peroxide and sol-gel methods. Microstructures, morphologies, compositions, optical and elec- trochemical properties of the composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), fourier-transform infra- red spectroscopy (FT-IR), UV-vis diffuse reflectance spectro- scopy (DRS), photoluminescence spectroscopy (PL), Brunauer- Emmett-Teller (BET), electrochemical impedance spectroscopy (EIS) and ion chromatography (IC) methods. The effects of different mass ratios of BaSnO3 and TiO2@HNTs, initial concen- tration and pH of methylene blue (MB) on the photocatalytic degradation performance of the composites were studied via photodegradation of MB under simulated sunlight irradiation. The characterization results showed that BaSnO3/TiO2 hetero- junction and halloysite nanotubes (HNTs) enhanced the electron-hole pairs separation. The BaSnO3/TiO2@HNTs (BTH- 0.6) composites presented the highest specific surface area (67.957 m2 /g), photocatalytic activity (92%), and MB (Ct = 40 mg/L, pH 7) degradation efficiency (2-4 times that of TiO2, BaSnO3 and BaSnO3/TiO2).