Construction of rutile/anatase TiO2 homojunction and metal-support interaction in Au/TiO2 for visible photocatalytic water splitting and degradation of methylene blue

Homojunction structure could present synergetic effect of an enhanced charge transfer and decreasing the electron-hole recombination. In this investigation, rutile/anatase TiO2 homojunction was prepared by sol-gel synthesis with nitric acid (HNO3) as peptizing agent. Au/TiO2 was prepared by photoreduction deposition process. The photocatalytic performance for water splitting and the degradation of methylene blue (MB) was evaluated. 1% Au/TiO2-HNO3 possessed good photocatalytic activity with hydrogen evolution rate of 8.77 mmol/h/g, and MB degradation efficiency of about 69.70% under visible light irradiation. The results indicated TiO2-HNO3 conceived optimum composition ratio of rutile and anatase phases to construct the homojunction structure enhancing charge transfer and decreasing the electron-hole recombination favorable for photocatalytic performance. Further, the strong metal-support interaction as well as the localized surface plasmon resonance (LSPR) of Au species accounted for the results of Au/TiO2 especially Au/TiO2- HNO3 possessing higher hydrogen evolution and degradation of MB performance than TiO2.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The study investigates the photocatalytic performance of Au/TiO2 and TiO2-HNO3 for water splitting and the degradation of methylene blue (MB). The results show that 1% Au/TiO2-HNO3 exhibits good photocatalytic activity with high hydrogen evolution rate and MB degradation efficiency under visible light irradiation. The TiO2-HNO3 homojunction structure enhances charge transfer and decreases the electron-hole recombination, while the strong metal-support interaction and localized surface plasmon resonance (LSPR) of Au species contribute to the superior performance of Au/TiO2.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.