Preparation and characterization of graphene oxide/Ag2CO3 photocatalyst and its visible light photocatalytic activity

Abstract

Graphene oxide (GO) was firstly fabricated from graphite powder by Hummers method. Then a series of GO/Ag2CO3 composite photocatalysts (0.1% GO/Ag2CO3, 0.5%GO/Ag2CO3, 1%GO/Ag2CO3, 4%GO/Ag2CO3) were synthesized by a facile liquid deposition process. The produced products were characterized by powder X-ray diffraction (XRD), N2 physical adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscope (FT-IR), Raman spectra and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). The photocatalytic activity of the samples was evaluated by photocatalytic degradation of methyl orange (MO) under visible light irradiation. The influence of GO concentration on the photocatalytic activity of GO/Ag2CO3 was investigated. The results showed that GO can be easily dispersed into Ag2CO3, producing well contacted GO/Ag2CO3 composite. Coupling of trace GO largely enhanced the visible light absorption. Moreover, GO could suppress the growth of Ag2CO3 grain crystals. With optimum GO content (0.5%), the degradation rate of MO is 85.37% after 120min light irradiation, which Exhibits 1.53 times activity of that of pure Ag2CO3. More importantly, a large improvement in stability was obtained over the composite. The increase in photocatalytic activity and stability could be mainly attributed to the coupling of GO which increased the surface area and suppressed the recombination rate of e−/h+ pairs.