Modified Graphitic Carbon Nitride Nanosheets for Efficient Photocatalytic Hydrogen Evolution

Considerable research efforts have been devoted to develop noble-metal-free cocatalysts coupled with semiconductors for highly efficient photocatalytic H-2 evolution as part of the challenge toward solar-to-fuel conversion. Herein, a new cocatalyst with excellent activity in the electrocatalytic H-2 evolution reaction (HER) that is based on Co sheathed in N-doped graphitic carbon nanosheets (Co@NC) was fabricated by a surfactant-assisted pyrolysis approach and then coupled with g-C3N4 nanosheets to construct a 2 D-2 D g-C3N4/Co@NC composite photocatalyst by a simple grinding method. As a result of advantages in effective electrocatalytic HER activity, suitable electronic band structure, and rapid interfacial charge transfer brought about by the 2 D-2 D spatial configuration, the g-C3N4/Co@NC photocatalyst that contained 4 wt % Co@NC presented a high photocatalytic H-2 generation rate of 15.67 mu mol h(-1) under visible-light irradiation (lambda >= 400 nm), which was 104.5 times higher than that of pristine g-C3N4. The optimum g-C3N4/Co@NC photocatalyst showed a high apparent quantum efficiency of 10.82 % at lambda=400 nm.