A self-assembled 2D/2D-type protonated carbon nitride-modified graphene oxide nanocomposite with improved photocatalytic activity

Abstract A surface charge modified g-C 3 N 4 was successfully prepared by protonation of nitric acid. Combination of the protonated g-C 3 N 4 (pCN) and graphene oxide (GO) layers created a 2D/2D-type composite (pCN/GO) under the synergistic effect of sonication-exfoliation and self-assembly. The obtained 2D nanostructure of pCN/GO was explored by electron microscopy analysis. The photocatalytic degradation of rhodamine B (RhB) and ciprofloxacin (CIP) showed a distinctly high efficiency of pCN/GO-5% with excellent stability, which is superior not only to that of g-C 3 N 4 , pCN and g-C 3 N 4 /GO-5% nanocomposites we prepared, but also to what was reported previously. The optimized combination of GO and pCN afforded the pCN/GO composite intimate interfacial contact within the heterojunction, which promoted the separation of photogenerated electron-hole pairs as evidenced by zeta potential, photoluminescence and photocurrent measurements. A visible-light photocatalytic degradation mechanism associated with pCN/GO nanocomposites was also proposed.