Preparation, Mechanism Study Of Photocatalytic Degradation SMZ Of Porous Materials-H₃PW₁₂O₄₀/Ag-TiO₂

In this paper, based on the advantages of POM/TiO2, TiO2 composite catalytic material, high efficientive heterogeneous photocatalytic porous material H3PW12O40/Ag-TiO2 is prepared by the method of combining sol-gel and hydrothermal treatment at a lower temperature. Composition, structure, optical absorption property, physicochemical properties, and surface morphology of the composite were characterized by the test technologies of XRD,Uv-vis/DRS,TEM,XPS.And under PLS-SXE300/300UV xenon lamp irradiation, sulfamethoxazole (SMZ) as a model of pollutant to simulate photocatalytic catalytic activity under sunlight and determine the optimum reaction conditions.while the photocatalytic degradates mechanism of sulfamethoxazole (SMZ) is discussed. Research shows that:Composite material H3PW12O40/Ag-TiO2 have the structure of anatase crystalline,with the composite H3PW12O40 uniformly dispersed in TiO2 lattice, and the Ag particles dispersed in the TiO2 surface in the form of single mass Ag0, and the size of the composites material is 10 nm. Composite materials not only at 200～380 nm have the absorption peak.but also at 400～600nm also have a strong absorption peak; Composite material have the structure of dual-pore,and the size of the micro-porosity and meso-porosity of porous material H3PW12O40/Ag-TiO2-0.7 and H3PW12O40/Ag-TiO2-1.6 are 0.43 nm and 3.8 nm,0.44 nm and 4.5 nm respectively. And the BET area are 172.8 m2/g,159.7 m2/g. The photocatalytic degradation activity.of composite materials H3PW12O40/Ag-TiO2-0.7 in the SMZ is highest under PLS-SXE300/300UV xenon lamp irradiation.The optimum reaction conditions of composite H3PW12O40/Ag-TiO2 to photodegrade SMZ are:the best loading of Ag is 0.7wt%, the amount of catalyst is 2.0g/L, the value of pH is 8.7,and the initial concentration is 20mg/L.Under this experimental conditions, the degradation of composite materials in the SMZ reached 99.9%.According to the photodegradation intermediates of SMZ can speculate that there may be three paths:active OH·radical respectively attack the SN bond and the NC bond,double bond and phenyl ring on the five-4C in the SMZ, and are completely mine into CO2, H2O and inorganic ion SO42-, NO3-, NH4+ finally.