Three-dimensional flower-like phosphorus-doped g-C3N4 with a high surface area for visible-light photocatalytic hydrogen evolution†
Abstract
Flower-like P-doped graphitic carbon nitride (g-C3N4) with a high surface area and porosity has been prepared via a facile, template-free, cost-effective and thermal copolymerization route, using phosphoric acid as the phosphorus source and a cyanuric acid–melamine complex as the supramolecular precursor. It could be found that phosphoric acid could stabilize the three-dimensional character of the as-prepared P-doped g-C3N4 and the g-C3N4 micro-flower consisted of ultrathin nanosheets which possessed abundant mesopores. The unique structure, combined with phosphorus heteroatom doping, promoted the utilization of visible light and improved the separation and mobility of photogenerated charges. The obtained P-doped g-C3N4 exhibited prominent photocatalytic performance in the water splitting for the hydrogen evolution reaction under visible light irradiation. The hydrogen evolution rate reached 256.4 μmol h−1, almost 24 times higher than that of pristine g-C3N4. Meanwhile, a possible mechanism for photocatalytic hydrogen evolution was proposed according to the results.