Construction of ultrathin 2D/2D g-C_3N_4/In_2Se_3 heterojunctions with highspeed charge transfer nanochannels for promoting photocatalytic hydrogen production

摘要

Reinforcing the photo-induced carrier separation and interfacial charge transfer are the pressing issue to elevate the photocatalyic hydrogen evolution efficiency of g-C3N4-based catalysts. To this end, a binary nanohybrid heterojunction of two-dimensional (2D) g-C3N4 and In2Se3 g-C3N4/In2Se3-X) was designed and used as the visible light photocatalyst. Benefited from the intimate 2D/2D heterojunction interface and the spontaneous polarization characteristic of ultrathin In2Se3 nanosheet, the g-C3N4/In2Se3 heterojunction could generate numerous high-speed charge transfer channels, and the vertical intrinsic electric field of In2Se3 would considerably inhibit the recombination of photogenerated charge. By taking advantage of these features, the 2D/2D g-C3N4/In2Se3 heterojunction nanosheets exhibited remarkably intensified visible-light-driven photocatalytic activity, the optimal g-C3N4/In2Se3 heterojunction nanosheets exhibit a hydrogen evolution rate of 4.8 mmol.g(-1).h(-1) that greatly higher than pure g-C3N4 (0.94 mmol.g(-1).h(-1)) and In2Se3. The photocatalytic mechanism and highspeed channels of interface charge transfer were investigated and discussed. This work can provide a possibility for design and construction of photocatalysts with high efficient separation of photoinduced carriers.