Carbonyl Linked Carbon Nitride Loading Few Layered MoS2 for Boosting Photocatalytic Hydrogen Generation

Pristine graphitic carbon nitride g-C3N4 materials, as a novel metal-free photocatalyst with moderate activity, have attracted intense interest. However, its fast photogenerated carriers recombination always induces a relative low performance. Herein, we for the first time report one new =C=O group linked g-C3N4 (CO-C3N4) through CO2-assisted thermal polymerization of urea. It is found that the edge =C=O groups work as the photogenerated electrons collection sites and then promote the carriers separation. The visible-light photo-tatalytic hydrogen evolution performance of our synthesized samples shows 1.85 times higher than that of the reference g-C3N4. To get a considerable visible-light driven photocatalytic hydrogen generation, a new few layered MoS2 with a small size (ca. 20 nm) is prepared through a liquid exfoliation and then is loaded onto the CO-C3N4. The optimal MoS2/CO-C3N4 sample gives the photocatalytic hydrogen evolution of 1990 and 1440 mu mol/(g*h) under the lambda > 400 and 420 illumination, higher than the reported values in the literature. The sample also shows a considerable excellent photocatalytic activity of 44.3 mu mol/(g*h) under LED-600 condition.