Few-layered MoS2 anchored on 2D porous C3N4 nanosheets for Pt-free photocatalytic hydrogen evolution

The Pt-free photocatalytic hydrogen evolution (PHE) has been the focus in the photocatalytic field. The catalytic system with the large accessible surface and good mass-transfer ability, as well as the intimate combination of co-catalyst with semiconductor is promising for the promotion of the application. Here, we have reported the design of the two-dimensional (2D) porous C3N4 nanosheets (PCN NS) intimately combined with few-layered MoS2 for the high-effective Pt-free PHE. The PCN NS were synthesized based on peeling the melamine-cyanuric acid precursor (MC precursor) by the triphenylphosphine (TP) molecular followed by the calcination, mainly due to the matched size of the (100) plane distance of the precursor (0.8 nm) and the height of TP molecular. The porous structure is favorable for the mass-transfer and the 2D structure having large accessible surface, both of which are positive to promote the photocatalytic ability. The few-layered MoS2 are grown on PCN to give 2D MoS2/PCN composites based on anchoring phosphomolybdic acid (PMo12) cluster on polyetherimide (PEI)-modified PCN followed by the vulcanization. The few-layered MoS2 have abundant edge active sites, and its intimate combination with porous PCN NS is favorable for the faster transfer and separation of the electrons. The characterization together with the advantage of 2D porous structure can largely promote the photocatalytic ability. The MoS2/PCN showed good PHE activity with the high hydrogen production activity of 4,270.8 mu mol.h(-1).g(-1) under the simulated sunlight condition (AM1.5), which was 7.9 times of the corresponding MoS2/bulk C3N4 and 12.7 times of the 1 wt.% Pt/bulk C3N4. The study is potentially meaningful for the synthesis of PCN-based catalytic systems.