Spatial Separation of Charge Carriers via Heterogeneous Structural Defects in Graphitic Carbon Nitride for Photocatalytic Hydrogen Evolution

Herein, a special mixed atmosphere of acetonitrile and hydrogen sulfide (H2S) is utilized to treat g-C3N4 nanosheets for engendering heterogeneous structural defects. In this strategy, a sulfur atom and a cyano group can be together introduced to the lattice of g-C3N4. It is also interesting that a small amount of nulvalent sulfur is produced to construct a binary composite via incomplete oxidization of H2S. The experimental and calculated results reveal that the sulfur atom and cyano group avail the efficient separation and shuttle the charge carriers across g-C3N4 nanosheets to prompt delocalization of redox active sites. Notably, the best photocatalytic rate of 1901 μmol·g–1·h–1 is attained for the S/g-C3+xN4+y nanophotocatalyst, 5.3 times faster than that of g-C3N4. In addition, AQEs of 33.5% and 13.1% are achieved under the irradiation of 405 and 420 nm, respectively. This work introduces S/g-C3+xN4+y as a highly active nanophotocatalyst that offers a potential application prospect for environmental remediation and energy storage and conversion.