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

In the work, visible-light-driven ZnIn 2 S 4 /TiO 2-x nanotube arrays were fabricated by defect-induced bandgap engineering, leading to high visible light responsive, and combining ZnIn 2 S 4 cocatalyst to improve separation of photogenerated carriers, thus enhancing photocatalytic H 2 production. [Display omitted] • A visible-light-driven ZnIn 2 S 4 /TiO 2-x nanotube arrays for fabricating the highly efficient photocatalysts is proposed. • The in-plane oxygen vacancies induce the high visible light responsive of TiO 2-x. • ZnIn 2 S 4 /TiO 2-x nanotube arrays prompt synergistic regulations of both absorption and separation benefits. • ZnIn 2 S 4 /TiO 2-x nanotube arrays exhibit high and stable 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. [ABSTRACT FROM AUTHOR]