Synthesis Of Graphene Oxide-supported Phosphotungstic Acid Complexes And Properties In The Catalysis

With the rapid development of industry, large amount of pollutant is discharged that results in seriously water pollution, which poses a great threaten to our daily life, so it is imperative to deal with it. Herein, we tried to couple Polyoxometalates(POMs), an environment-friendly material with the properties of oxidation as well as good photocatalytic activity, with graphene oxide(GO) to synthesize the POM/GO hybrid material, for utilizing the functional groups and the unique structure of GO to support POM as well as enhance the properties of oxidation and photocatalysis, which can extand the application of POM to water pollution treatment.The main contents of this paper are as follows:1. PW12/GO-NH2 hybrid has been synthesized by anchoring H3PW12O40(PW12) on 3-aminopropyltriethoxysilane modified graphene oxide(GO-NH2) using a facile impregnation method. The structure of the obtained hybrid was characterized by elemental analysis, X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy(XPS), transmission electron microscopy(TEM), UV-vis diffuse reflectance spectroscopy(DRS), photoluminescence spectroscopy(PL), electrochemical impedance spectroscopy(EIS) and photocurrent responsed. The results show that PW12 was successfully anchored to GO-NH2, the Keggin structure of PW12 is still preserved in PW12/GO-NH2 and interactions occur between PW12 anions and GO-NH2 sheets, which is benefit for the enhancement of oxidation and photocatalysis of PW12.2. The removal efficiency for methyl orange(MO) of PW12/GO-NH2 was conducted. The results show that about 61.8% of MO is adsorbed onto the PW12/GO-NH2 hybrid upon 2 h of mixing, and after 2 h of irradiation under a 100 W high-pressure mercury lamp, MO is further decreased to 17.7%. The adsorption capacity of PW12/GO-NH2 hybrids is enhanced as compared with GO-NH2, and the photocatalytic activity is better than the homogenous photocatalyst PW12(1.36 times). Furthermore, the photocatalytic degradation mechanism of MO over the PW12/GO-NH2 hybrid under irradiation is carried out, revealing that the oxidation of MO by O2?-and ?OH plays a major role in the photocatalytic degradation process.3. The catalytic oxidative desulfurization of model oil with PW12/GO-NH2 is performed in the presence of H2O2 oxidant. The effects of temperature, the dose of catalysts, H2O2/DBT molar ratio and solvents were investigated in detail. It reveals that, PW12/GO-NH2 exhibit the best catalytic activity compared with PW12, GO-NH2 as well as the mixture of them, the sulfur removal in n-octane phase can reach to 100% when react 2 h with the temperature of 60 oC. The efficiency for the removal of DBT is still preserved with 90% after four cycles.