Construction of novel TiO2/Bi4Ti3O12/MoS2 core/shell nanofibers for enhanced visible light photocatalysis

TiO2/Bi4Ti3O12 hybrids have been widely prepared as promising photocatalysts for decomposing organic contaminations. However, the insufficient visible light absorption and low charge separation efficiency lead to their poor photocatalytic activity. Herein, a robust methodology to construct novel TiO2/Bi4Ti3O12/MoS2 core/shell structures as visible light photocatalysts is presented. Homogeneous bismuth oxyiodide (BiOI) nanoplates were immobilized on electrospun TiO2 nanofiber surface by successive ionic layer adsorption and reaction (SILAR) method. TiO2/Bi4Ti3O12 core/shell nanofibers were conveniently prepared by partial conversion of TiO2 to high crystallized Bi4Ti3O12 shells through a solid-state reaction with BiOI nanoplates, which is accompanied with certain transition of TiO2 from anatase to rutile phase. Afterwards, MoS2 nanosheets with several layers thick were uniform decorated on the TiO2/Bi4Ti3O12 fiber surface resulting in TiO2/Bi4Ti3O12/MoS2 structures. Significant enhancement of visible light absorption and photo-generated charge separation of TiO2/Bi4Ti3O12 were achieved by introduction of MoS2. As a result, the optimized TiO2/Bi4Ti3O12 /MoS2-2 presents 60% improvement for photodegrading RhB after 120 min irradiation under visible light and 3 times higher of apparent reaction rate constant in compared with the TiO2/Bi4Ti3O12. This synthetic method can also be used to establish other photocatalysts simply at low cost, therefore, is suitable for practical applications. (C) 2019 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.