Preparation And Photocatalysis Of Tin Dioxide Composites Photocatalysts

With more concerned about environment quality nowadays,dyeing wastewater that has the characteristic of large quantity,strong color,high chemical oxygen demand(COD),should be treated with more environmentally friendly technology.Photocatalytic technology is a good choice to deal with dyeing wastewater.SnO2 has excellent photoelectronic properties and it was applied in batteries,gas sensors and photocatalysis area.In this study,three different SnO2 composites were synthesized with other materials and the photocatalytic performance of these composites was researched through degrading methyl orange in different conditions.The Kaolin clay/SnO2/Sn2+ composites were synthesized via hydrothermal method,and the morphology and photocatalytic properties were characterized by different analysis.Results showed that kaolin clay recombined with SnO2/Sn2+successful,Sn2+ existed in the composites,and the morphology was of randomness and assembly,the lattice corresponds to(110)plane of SnO2.The band gap of SnO2/Sn2+ became lower after modifying with kaolin clay,and the 4%kaolin clay/SnO2/Sn2+ has the band gap of 2.62eV.The 4%kaolin clay/SnO2/Sn2+has the optimal photocatalytic activity in degrading methyl orange under 500W xenon lamp irradiation,10mg/L methyl orange degradation efficiency reached 98.2%within 120 minute when photocatalyst dosage of 50mg.With the photocatalyst dosage increased,the methyl orange degrading process became better in acidic condition.The methyl orange degrading process became slowly after the methyl orange became higher,however,the total amount of degrading methyl orange became more.The SnO2/SnWO4 composites of different mole ratio were synthesized.The composites consisted of random nano slice which assembled together slightly.SnO2 and SnWO4 were combined successfully following mole ratio.The band gap of SnO2/SnWO4 was lower than of the pure SnO2,and SnO2/SnWO4 has the photocatalytic activity in degrading methyl orang when illuminated by visible light.Methyl orange degradation reached 58.7%when catalyzed by SnO2/SnWO4(1:2)photocatalyst,and only7.0%under SnWO4 photocatalyst.It has the optimal photocatalytic activity in degrading methyl orange when photocatalyst dosage of 75mg,and acidic condition was good for degrading methyl orange.The degradation reached 50.0%after SnO2/SnWO4(1:2)photocatalyst was reused 5 times.The magnetic Ni0.5Zn0.4Cu0.1Fe2O4/SnO2 composites of different mass ratio were synthesized via hydrothermal method.The partical size of Ni0.5Zn0.4Cu0.1Fe2O4 was 10nm-30nm,and it was consist of nanosphere.Ni0.5Zn0.4Cu0.1Fe2O4/SnO2 had bigger size than Ni0.5Zn0.4Cu0.1Fe2O4.Ni0.5Zn0.4Cu0.1Fe2O4/SnO2 composites had great magnetism,it was regained easily.It had excellent photocatalytic activity under mercury lamp.20mg/L methyl orange degradation efficiency reached 68.8%within 60 minute when Ni0.5Zn0.4Cu0.1Fe2O4/SnO2(1:1)photocatalyst dosage of 50mg.It remained good photocatalytic activity after using 3 times.