An S-scheme heterojunction formed using orthorhombic NiNb2O6 and discrete TiO2 nanospheres enhances the rate of photocatalytic hydrogen evolution from aqueous glycerol solution

초록

This study presents the successful synthesis of orthorhombic NiNb2O6 nanoparticles and monodispersed titania nanospheres utilizing ethanol-assisted solvothermal method. The presence of alcohol facilitated the formation of hydrogen bonds with nuclei, promoting nanosphere growth. Then the titania-nanospheres were seamlessly integrated with NiNb2O6 nanoparticles. This integration resulted in the establishment of S-scheme heterojunction at the interface of TiO2 and NiNb2O6. As loading of NiNb2O6 nanoparticles increased, the photocatalytic activity exhibited an initial surge before subsequently decreasing. To further profound understanding of the materials, we employed EPR and VB-XPS analysis to unveil the exhibited mechanism and band edge positions of TiO2 and NiNb2O6. In addition to addressing catalytic activity, this study delves into the impact of various parameters such as glycerol, time on stream, catalyst loading and reusability, which led to the identification of optimal experimental conditions, under which the photocatalyst delivered significant H2 production rate of 114 mmol h- 1.g- 1 Furthermore, solar-to-H2 conversion efficiency also computed.

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