Enhancing hydrogen evolution of water splitting under solar spectra using Au/TiO2 heterojunction photocatalysts

An effective improvement of hydrogen evolution from water splitting under solar light irradiation was investigated using quantum dots (QDs) compounds loaded onto a Au/TiO2 photocatalyst. First, Au/TiO2 was prepared by the deposition-precipitation method, and then sulfide QDs were loaded onto the as-prepared Au/TiO2 by a hydrothermal method. QDs were loaded onto Au/TiO2 to enhance the energy capture of visible light and near infrared light of the solar spectrum. The results indicated that the as-prepared heterojunction photocatalysts absorbed the energy from the range of ultraviolet light to the near infrared light region and effectively reduced the electron-hole pair recombination during the photocatalytic reaction. Using a hydrothermal temperature of 120 degrees C, the as-prepared (ZnS-PbS)/Au/TiO2 photocatalyst had a PbS QDs particle size of 5 nm, exhibited an energy gap of 0.92 eV, and demonstrated the best hydrogen production rate. Additionally, after adding 20 wt % methanol as a sacrificial reagent to photocatalyze for 5 h, the hydrogen production rate reached 5011 mmol g(-1) h(-1). (C) 2021 The Author(s). Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

Automated summary

The hydrogen evolution from water splitting under solar light irradiation was effectively improved by loading quantum dots (QDs) compounds onto a Au/TiO2 photocatalyst. The results showed that the as-prepared heterojunction photocatalysts absorbed energy from a wide range of light spectrum and minimized electron-hole pair recombination, leading to enhanced hydrogen production rate.