Silver cyanamide nanoparticles decorated ultrathin graphitic carbon nitride nanosheets for enhanced visible-light-driven photocatalysis

Abstract

Metal cyanamide compounds are an emerging class of photoactive materials for solar energy applications. Although silver cyanamide (Ag₂NCN) applied in visible-light-driven photocatalysis has been demonstrated, the photocatalytic performance is unsatisfactory. Herein, a composite of Ag₂NCN nanoparticles supported on ultrathin carbon nitride (g-C₃N₄) nanosheets is synthesized by combining thermal annealing and an in situ precipitation method. Due to the band alignment between Ag₂NCN and g-C₃N₄, a type-II semiconductor heterojunction is built up to improve the photocatalytic activity of pristine Ag₂NCN. The as-prepared nanocomposites exhibit enhanced photocatalytic activity for organic dye decolorization under visible light irradiation compared with pure Ag₂NCN and pristine g-C₃N₄ nanosheets. The enhancement of photocatalytic performance can be ascribed to the synergistic effects between Ag₂NCN and g-C₃N₄, which include improved light absorption, superior charge separation, uniform dispersion and smaller size of Ag₂NCN loaded on high surface area g-C₃N₄ nanosheets. The kinetics model and degradation mechanism of the nanocomposites are also proposed.