Ag/Nanodiamond/g-C3N4 heterostructures with enhanced visible-light photocatalytic performance

Efficient separation of photogenerated carriers and light harvesting are the two key factors for high photocatalytic performance. In this work, a novel double-heterojunction silver/nanodiamond/graphite-carbon nitride (Ag/ND/g-C3N4) structured photocatalyst has been synthesized. In comparison to single-heterojunction Ag/g-C3N4, the double-heterojunction Ag/ND/g-C3N4 photocatalyst presents with a 4.9-times enhancement in H2 evolution from water splitting and 2.4-times promotion in degrading organic pollution under visible-light irradiation. Furthermore, the Ag/ND/g-C3N4 exhibits good photostability after four-run test. The enhanced photocatalytic activity can be attributed to the synergetic effect of surface plasmon resonance from Ag, optical confinement from ND and suitable band alignment in the double-heterojunction structure, which boost the light absorption capacity and increase the photogenerated charge separation of g-C3N4. This study provides a reference for the development of efficient carbon based photocatalysts, which can be used not only for the production of H-2 from water splitting, but also for the photodegradation of pollutants under visible light irradiation.