Ag₂CrO₄ nanoparticles loaded on two-dimensional large surface area graphite-like carbon nitride sheets: Simple synthesis and excellent photocatalytic performance

Graphite-like carbon nitride (g-C₃N₄) with a large surface area was prepared through thermal condensation of guanidine hydrochloride at 650 °C. Various amounts of silver chromate (Ag₂CrO₄) nanoparticles with small size were highly loaded on the g-C₃N₄ by a simple co-precipitation method at room temperature. The chemical constituents, surface structure and optical properties of the resultant Ag₂CrO₄/g-C₃N₄ composites were thoroughly characterized. And the photocatalytic performances were evaluated by degradation of Rhodamine B (RhB) and phenol, the experimental results indicated that the as-prepared Ag₂CrO₄/g-C₃N₄ composites presented excellent photocatalytic activity under visible-light irradiation. With the mass ratio of Ag₂CrO₄ to g-C₃N₄ at 1:2, the Ag₂CrO₄/g-C₃N₄ composites exhibited optimal photocatalytic activity for degrading RhB, approximately 6.1 and 10.4 times higher than those on pure g-C₃N₄ and bare Ag₂CrO₄ particles. The improved photocatalytic activity was mainly attributed to the combined effect including the larger surface area, highly dispersed smaller Ag₂CrO₄ nanoparticles, stronger visible absorption and higher charge separation efficiency of the Ag₂CrO₄/g-C₃N₄ composites. Moreover, the possible mechanism for the photocatalytic activity was tentatively proposed.