Template free fabrication of porous g-C₃N₄/graphene hybrid with enhanced photocatalytic capability under visible light

Abstract

Graphene modified porous g-C3N4 (porous g-C3N4/graphene) with efficient photocatalytic capability under visible light irradiation was fabricated by means of calcinations without extra templates. We expected that the photocatalytic capability of this hybrid photocatalyst could be enhanced by the efficient visible light absorption owing to the porous structure and efficient photogenerated charge separation owing to the heterojunction built between porous g-C3N4 and graphene. Scanning electron microscopy images demonstrated that the as prepared photocatalyst is composed of graphene and porous g-C3N4. The ultraviolet–visible diffuse reflectance spectrum shows that optical absorption for porous g-C3N4/graphene is more intensive than for pristine g-C3N4/g-C3N4/graphene/porous g-C3N4. The enhanced generation of photocurrent under visible light irradiation (λ>400 nm) is observed using the porous g-C3N4/graphene. The results of photocatalytic experiments under visible light irradiation reveal that the pseudo first order kinetic constant of photocatalytic degradation of methylene blue using the porous g-C3N4/graphene is six times as great as that in pristine g-C3N4, showing the advantage of the unique structure in the porous g-C3N4/graphene for efficient photocatalysis.