Synthesis of TiO2/g-C3N4 nanocomposites as efficient photocatalysts dependent on the enhanced photogenerated charge separation

•Different TiO2/bulk g-C3N4 nano-composites are synthesized by a wet chemical method.•Coupling with TiO2 obviously promotes photogenerated charge separation of bulk g-C3N4.•Promoted charge separation leads to the enhanced photoactivities for producing H2.•An efficient TiO2/nanosheet g-C3N4 photocatalyst is developed by the similar strategy.

We have synthesized different mass ratios of effectively-contacted TiO2/bulk g-C3N4 composites (T/CN) by a wet chemical method, and evaluated their photocatalytic activities for degrading acetaldehyde and producing H2. It is clearly demonstrated by means of surface photovoltage responses and photoluminescence spectra that the photogenerated charge carriers in the T/CN nanocomposites with a proper mass ratio of T display much higher separation in comparison to CN alone. This is well responsible for the enhanced photocatalytic activities of CN after coupling with nanocrystalline anatase TiO2. Interestingly, it is also applicable to the resulting CN nanosheet (about 3 nm) with higher photoactivity than the bulk one. As a result, the TiO2/CN-nanosheet composites as efficient photocatalysts have been successfully developed. Moreover, it is confirmed that the enhanced photoactivity for resulting nanocomposites are attributed to the promoted charge transfer and separation from CN to TiO2.

Graphical abstractCharge separation of g-C3N4 is enhanced after coupling TiO2, leading to the improved photoactivities for degrading pollutants and producing H2.Figure optionsDownload full-size imageDownload as PowerPoint slide