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

• Published in: ChemistrySelect (Weinheim) Vol. 6; no. 40; pp. 10817 - 10826
• Main Authors: Li, Taishan, Jiang, Ao, Di, Yuli, Zhang, Dafu, Zhu, Xiaodong, Deng, Lin, Ding, Xiaoyu, Chen, Shanhua
• Format: Journal Article
• Language: English
• Published: 27.10.2021
• Subjects: BaSnO3/TiO2@HNTs composite; Halloysite nanotubes; Perovskite BaSnO3; Photocatalysis; TiO2 nanoparticles
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202102834

The novel BaSnO3/TiO2@HNTs photocatalysts were successfully synthesized by co‐precipitation peroxide and sol‐gel methods. Microstructures, morphologies, compositions, optical and electrochemical properties of the composites were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), fourier‐transform infrared spectroscopy (FT‐IR), UV‐vis diffuse reflectance spectroscopy (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 concentration 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 heterojunction 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). Furthermore, the capture experiments verified that ⋅OH, h+ and ⋅O2− were the main active substances during the photo‐catalytic reaction, and a possible degradation mechanism was suggested for their photocatalytic degradation in the presence of BaSnO3/TiO2@HNTs. Under simulated sunlight irradiation, the photocatalyst of BaSnO3/TiO2@HNTs showed higher photodegradation activity than pure BaSnO3, pure TiO2 and BaSnO3/TiO2. Compared with TiO2, the conduction band potential of BaSnO3 is higher than that of TiO2, which is beneficial to the transfer of photogenerated carriers and reduces the composite efficiency of electron hole pairs, thus improving the photocatalytic performance of the composites.