Spatial Separation of Charge Carriers via Heterogeneous Structural Defects in Graphitic Carbon Nitride for Photocatalytic Hydrogen Evolution
Xinyu Zhang, Chengwu Yang, Zhe Xue, Chunxiang Zhang, Jiaqian Qin, Riping Liu
Abstract
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.