High visible light responsive ZnIn2S4/TiO2-x induced by oxygen defects to boost photocatalytic hydrogen evolution

Photocatalytic H 2 evolution provides an upcoming route for the production of clean fuel via the conversion of solar energy. TiO 2 , as a potential semiconductor material, is restricted by its faint absorption of visible light, thus limiting its application in water splitting. Herein, high visible light responsive ZnIn 2 S 4 /TiO 2-x nanotube arrays for photocatalytic hydrogen evolution were fabricated by two-step reaction. ZnIn 2 S 4 /TiO 2-x nanotube arrays exhibited the photo response from UV to visible-light region due to the introduction of oxygen vacancies and visible-light driven ZnIn 2 S 4 . Moreover, the heterojunction improved the separation of photogenerated carriers and boosted the electron transfer from ZnIn 2 S 4 to TiO 2-x , thereby increasing the longevity of active electrons, which enhanced the photocatalytic activity for hydrogen evolution. An outstanding H 2 production rate of 581.1 μmol h −1 g −1 was obtained and an apparent quantum yield (AQY) up to ∼ 1.42% was achieved. This work demonstrates that the defect-induced bandgap engineering of semiconductor photocatalysts is a potential way to extend the optical absorption property of TiO 2 to visible light even or NIR and enhance the photocatalytic activity.