Construction of Sn3O4–Ag–Ag2O Z-scheme heterojunction on TiO2 nanotube arrays: Photocatalytic dye degradation and H2 evolution

Abstract

Taking advantage of efficient photoelectron transfer and high redox capacity, the indirect Z-scheme heterojunction was constructed by the hydrothermal deposition of Sn3O4–Ag–Ag2O nanoparticles on TiO2 nanotube arrays (TiO2 NTs). The morphology, microstructure and photocatalytic property of samples were adjusted by the Ag+ concentration, and the Ag-0.8 sample prepared with 0.8 mmol AgNO3 exhibited the attractive photocatalytic dye degradation and H2 evolution. The as-prepared samples displayed outstanding photocatalytic capacity and stability toward organic dye degradation and Cr(VI) removal, and the visible light-driven photocatalytic H2 production rate achieved as high as 55.79 μmol cm−2 h−1. The indirect Z-scheme electron transfer mechanism was investigated based on the photocatalytic data and electron spin resonance (ESR) signal, which provided the guidance to explain the enhanced optical and photocatalytic property. The Z-scheme heterojunction construction would exhibit intense attraction in the photocatalyst design and application.