Efficient hydrogen evolution with ZnO/SrTiO3 S-scheme heterojunction photocatalyst sensitized by Eosin Y.

Developing efficient, stable, and cheap photocatalysts for H 2 production has aroused great interest among researchers. Herein, noble-metal-free ZnO/SrTiO 3 composite photocatalysts have been successfully prepared by hydrothermal method. X-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffusion spectroscopy, and photoluminescence spectroscopy are used to characterize the obtained samples. The photocatalytic water splitting for H 2 production by ZnO/SrTiO 3 has been studied under simulated sunlight irradiation by using triethanolamine as a sacrificial agent and Eosin Y (EY) dye as a sensitizer. The orthogonal experiments are designed to optimize the photocatalytic reaction conditions for practical purposes. The influencing extents and trends of the factors have been investigated, including the catalyst composition and dosage, pH value of the solution, triethanolamine, and EY addition. Under the optimum conditions, the H 2 production rate with ZnO/SrTiO 3 is up to 16006.12 μmol g−1 h−1. The excellent performance of ZnO/SrTiO 3 is attributed to the formation of a step-scheme (S-scheme) heterojunction, which promotes the separation of photocarriers and reduces their recombination probability. • ZnO/SrTiO 3 S-scheme photocatalysts are prepared by hydrothermal method. • The maximum hydrogen production rate of 16006.12 μmol g−1 h−1 is achieved. • Orthogonal experiments are designed to optimize the reaction conditions. • The photocatalytic mechanism of hydrogen production is proposed. [ABSTRACT FROM AUTHOR]