A facile one-step fabrication of holey carbon nitride nanosheets for visible-light-driven hydrogen evolution

Two-dimensional polymeric carbon nitride (PCN) nanosheets have evoked considerable attention as functional photocatalyst with unique physicochemical properties and potentials in the applications. Despite significant advances in the fabrication of PCN nanosheets, it remains a considerable challenge to prepare PCN nanosheets by an inexpensive and high-yield method. Here we illustrated a new effort to synthesize PCN nanosheets by adding reusable ammonia decomposition catalyst in the thermal condensation process. The melamine was used as the precursor, which will slowly release ammonia during thermal polymerization. The industrial catalyst (Z204, Ni species as active component on Al2O3) is used to decompose ammonia then promote the sluggish ammonia release during the polymerization, leading to the successful fabrication of holey carbon nitride nanosheets (CNS). The resultant holey CNS exhibits a higher Brunauer-Emmett-Teller (BET) surface area, which is 15.8 folds of bulk PCN. The enlarged BET surface area with more exposed active edges and sites, and significantly promoted charge transfer ability, combining with a stronger thermodynamic driving force, led to a remarkably boosted solar driven H2 evolution performance.