2D porous graphitic C3N4 nanosheets/Ag 3PO4 nanocomposites for enhanced visible-light photocatalytic degradation of 4-chlorophenol

Abstract

A novel visible-light-activated photocatalyst consisting of porous graphitic C3N4 nanosheets and Ag3PO4 nanoparticles were synthesized through a tunable in situ deposition method. The morphology and microstructure of the C3N4/Ag 3PO4 nanocomposites were carefully characterized by scanning electron microscope, TEM, X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectra, and so on. The porous C 3N4/Ag3PO4 nanocomposites were featured by the typical platelet-like morphology, with an average crystallite size of about 39 nm. The coexistence of porous graphitic C3N 4 nanosheets and Ag3PO4 nanoparticles is confirmed via the XRD and EDX results. Owing to its narrower band gap of Ag 3PO4, the nanocomposites displayed a significant redshift of UV-Vis spectral absorption edge together with expanded light absorption in comparison with g-C3N4 nanosheets. The photocatalytic activity of the prepared C3N4/Ag3PO4 nanocomposites is demonstrated by the photodegradation of 4-chlorophenol (4-CP). The C3N4/Ag3PO4 nanocomposites displayed higher photocatalytic activity than pure C 3N4 or Ag3PO4, which could be attributed to the interfacial effect of the nanocomposites in inhibiting the unfavorable recombination of photogenerated electrons and holes. Electron spin resonance spin-trap study implied that the generation of hydroxyl radicals plays the key role in the photodegradation of 4-CP by the C3N 4/Ag3PO4 nanocomposites under visible light irradiation.