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

Abstract

Black TiO2 nanobelts/g-C3N4 nanosheets laminated heterojunctions (b-TiO2/g-C3N4) 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, N2 adsorption, and UV-visible diffuse reflectance spectroscopy, respectively. The results show that special laminated heterojunctions are formed between black TiO2 nanobelts and g-C3N4 nanosheets, which favor the separation of photogenerated electron-hole pairs. Furthermore, the presence of Ti3+ and g-C3N4 greatly enhance the absorption of visible light. The resultant b-TiO2/g-C3N4 materials exhibit higher photocatalytic activity than that of g-C3N4, TiO2, b-TiO2 and TiO2/g-C3N4 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-TiO2/g-C3N4 is ~9 times higher than that of pristine TiO2. Therefore, the high-efficient laminated heterojunction composites will have potential applications in fields of environment and energy.

Shape Controlled Synthesis of Copper Vanadate Platelet Nanostructures, Their Optical Band Edges, and Solar-Driven Water Splitting Properties

“…Photoelectrochemical (PEC) conversion of solar energy into chemical forms is a major scientific challenge and is extensively pursued in research due to its promising environmental energy sustainability. Owing to exceptional optical properties and ease in synthesis, numerous metal oxide semiconductors such as TiO 2 1 – 3 , Cu 2 O 4 , Fe 2 O 3 5 , ZnO 6 , WO 3 7 , and BiVO 4 8 etc. have been investigated as photoelectrode materials for solar-driven PEC water splitting.…”

Black Si-doped TiO2 nanotube photoanode for high-efficiency photoelectrochemical water splitting

“…22,49 Furthermore, the narrowed band gap could improve optical absorption. 31 Moreover, Si-doping favored the separation process of the photoinduced electrons and holes. 19,50 Once illuminated, the photogenerated holes would accumulate at the surface of the Ti-Si-O nanotubes for water oxidation (H 2 O + 2h + / 2H + + 1/2O 2 ).…”

g-C3N4-Based Nanomaterials for Visible Light-Driven Photocatalysis

“…Noble metal-promoted g-C3N4 offers improved UV and visible light harvesting, fast molecular diffusion, and a high density of photoactive sites [100][101][102]. TiO2/g-C3N4 heterojunctions have been fabricated by a two-step hydrothermal-calcination route from melamine, followed by an in-situ solid-state reaction [103]. The resulting TiO2/g-C3N4 g-C 3 N 4 has also been coupled with semiconductors and metal nanoparticles that exhibit visible light surface plasmon resonances to extend their spectral range.…”

“…Other g-C 3 N 4 nanocomposites were investigated with a range of materials and morphologies [39,82,91,, to access different charge transfer mechanisms between g-C 3 N 4 and the other components. These include a g-C 3 N 4 -based type II heterojunction [103], g-C 3 N 4 -based p-n heterojunction [91,129], g-C 3 N 4 -based Z-scheme heterojunction [113,130], g-C 3 N 4 /metal heterojunction [100,102], and a g-C 3 N 4 /carbon heterojunction [131]. The design of g-C 3 N 4 heterojunction photocatalysts is an attractive strategy to tune the electronic structure and redox potentials for visible-light absorption photocatalytic H 2 generation.…”