Black TiO2 nanobelts/g-C3N4 nanosheets Laminated Heterojunctions with Efficient Visible-Light-Driven Photocatalytic Performance

Abstract

Abstract Black TiO 2 nanobelts/g-C 3 N 4 nanosheets laminated heterojunctions (b-TiO 2 /g-C 3 N 4 ) as visible-light-driven photocatalysts are fabricated through a simple hydrothermal-calcination process and an in - situ solid-state chemical reduction approach, followed by the mild thermal treatment (350 °C) in argon atmosphere. The prepared samples are evidently investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, N 2 adsorption, and UV-visible diffuse reflectance spectroscopy, respectively. The results show that special laminated heterojunctions are formed between black TiO 2 nanobelts and g-C 3 N 4 nanosheets, which favor the separation of photogenerated electron-hole pairs. Furthermore, the presence of Ti 3+ and g-C 3 N 4 greatly enhance the absorption of visible light. The resultant b-TiO 2 /g-C 3 N 4 materials exhibit higher photocatalytic activity than that of g-C 3 N 4 , TiO 2 , b-TiO 2 and TiO 2 /g-C 3 N 4 for degradation of methyl orange (95%) and hydrogen evolution (555.8 μmol h −1 g −1 ) under visible light irradiation. The apparent reaction rate constant (k) of b-TiO 2 /g-C 3 N 4 is ~9 times higher than that of pristine TiO 2 . Therefore, the high-efficient laminated heterojunction composites will have potential applications in fields of environment and energy.