Simple one-pot, high-yield synthesis of 2D graphitic carbon nitride nanosheets for photocatalytic hydrogen production.

2-Dimensional (2D) graphitic carbon nitrate (g-C 3 N 4 ) nanosheets are particularly interesting photocatalytic materials because of their large surface area and excellent photoelectric properties. However, it remains challenging to synthesize 2D g-C 3 N 4 nanosheets with high yield and high activity simultaneously. In this work, a urea-assisted one-pot method was developed in which the decomposition of urea released NH 3 gas which exfoliated bulk g-C 3 N 4 into thin nanosheets and generated pores and wrinkles on their surface. The product g-C 3 N 4 nanosheets therefore possessed abundant surface active sites for interaction with reactants and showed enhanced light utilization efficiency, giving rise to their improved hydrogen production activity which was 3.36 times higher than that of their bulk counterpart. Importantly, the yield of g-C 3 N 4 nanosheets using this method was almost doubled compared to a previously reported ammonium chloride (NH 4 Cl) assisted method. Given that g-C 3 N 4 nanosheets are building blocks for various photocatalysts, the current synthetic method which produces g-C 3 N 4 nanosheets with high yield and high activity shall pave the way for high-performance photocatalytic applications such as hydrogen production and more.