Controllable construction 2D-CN photocatalyst for degradation MBT and mechanism insights

A nonmetal two-dimensional carbon nitride (2D-CN) with different thickness is constructed via the facile hy-drothermal (adjusting the solution pH to 4.0, 7.0 and 10.0) and calcination method. The 2D-CN-7.0 displays the dramatically enhanced photocatalytic activity (82%) for degrading 2-mercaptobenzothiazole (MBT), originating from the ultrathin 2D structural improved transfer efficiency of charge carriers, greatly decrease the diffusion path of electrons/holes to MBT, accelerating the reaction rate. More importantly, we find that there are no rules can be followed between the band gap and the thickness of CN by density functional theory (DFT) computation theoretically and experimentally. Also, the possible mechanism for the enhancement of photocatalytic perfor-mance, the degradation pathway of MBT, photogenerated carrier transfer behaviors are also discussed in depth. This research provides a new strategy to control the thickness of CN to improve photocatalytic activity.

Automated summary

A nonmetal two-dimensional carbon nitride (2D-CN) with different thickness was synthesized by a facile hydrothermal and calcination method. The 2D-CN-7.0 exhibited significantly enhanced photocatalytic activity (82%) for degrading 2-mercaptobenzothiazole (MBT), attributed to the ultrathin 2D structure that improved the transfer efficiency of charge carriers and reduced the diffusion path to MBT, resulting in accelerated reaction rates. Density functional theory (DFT) computation and experimental results showed no correlation between band gap and CN thickness. The research also discussed the possible mechanisms for the enhanced photocatalytic performance, degradation pathway of MBT, and photogenerated carrier transfer behaviors in detail. This study provides a novel strategy to control the thickness of CN for improved photocatalytic activity.