Crystal Design and Photoactivity of TiO₂ Nanorod Template Decorated with Nanostructured Bi₂S₃ Visible Light Sensitizer

In this study, TiO₂-Bi₂S₃ composites with various morphologies were synthesized through hydrothermal vulcanization with sputtering deposited Bi₂O₃ sacrificial layer method on the TiO₂ nanorod templates. The morphologies of decorated Bi₂S₃ nanostructures on the TiO₂ nanorod templates are controlled by the duration of hydrothermal vulcanization treatment. The Bi₂S₃ crystals in lumpy filament, nanowire, and nanorod feature were decorated on the TiO₂ nanorod template after 1, 3, and 5 h hydrothermal vulcanization, respectively. Comparatively, TiO₂-Bi₂S₃ composites with Bi₂S₃ nanowires exhibit the best photocurrent density, the lowest interfacial resistance value and the highest photodegradation efficiency towards Rhodamine B solution. The possible Z-scheme photoinduced charge separation mechanism and suitable morphology of Bi₂S₃ nanowires might account for the high photoactivity of TiO₂ nanorod-Bi₂S₃ nanowire composites.