Tuneable Functionalization of Glass Fibre Membranes with ZnO/SnO₂ Heterostructures for Photocatalytic Water Treatment: Effect of SnO₂ Coverage Rate on the Photocatalytic Degradation of Organics

• Main Authors: Vincent Rogé, Joffrey Didierjean, Jonathan Crêpellière, Didier Arl, Marc Michel, Ioana Fechete, Aziz Dinia, Damien Lenoble
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Catalysts
• Subjects: photocatalysis; ZnO; SnO₂; atomic layer deposition
• Online Access: https://www.mdpi.com/2073-4344/10/7/733

The construction of a ZnO/SnO₂ heterostructure is considered in the literature as an efficient strategy to improve photocatalytic properties of ZnO due to an electron/hole delocalisation process. This study is dedicated to an investigation of the photocatalytic performance of ZnO/SnO₂ heterostructures directly synthesized in macroporous glass fibres membranes. Hydrothermal ZnO nanorods have been functionalized with SnO₂ using an atomic layer deposition (ALD) process. The coverage rate of SnO₂ on ZnO nanorods was precisely tailored by controlling the number of ALD cycles. We highlight here the tight control of the photocatalytic properties of the ZnO/SnO₂ structure according to the coverage rate of SnO₂ on the ZnO nanorods. We show that the highest degradation of methylene blue is obtained when a 40% coverage rate of SnO₂ is reached. Interestingly, we also demonstrate that a higher coverage rate leads to a full passivation of the photocatalyst. In addition, we highlight that 40% coverage rate of SnO₂ onto ZnO is sufficient for getting a protective layer, leading to a more stable photocatalyst in reuse.