Study On The Photocatalysis Performance Of Metal Oxide And Metal Sulfide

A large amount of containing Cr and dye wastewater is discharged with the rapid development of global economy and increasement of population.Hence,the efficient removal of pollutant to is a critical issue.In the paper,the pollution present situation of heavy metals and dye,their harm and the common processing methods were introduced in briefly.The photocatalysis technology were focused.Then the synthesis and application of different types metal oxide or sulfide were carried out.The research contentsinclude as follows:First,g-C3N4/SnS2@SnO2 nanocompositeswereprepared under gentle solvothermal conditions.The photocatalysis behaviors of Cr(?)on g-C3N4/SnS2@SnO2 were studied.The SEM,TEM,and DRS of g-C3N4/SnS2@SnO2 displayed that hexagonal structure of SnS2@SnO2deposited on the porosity structure of g-C3N4;The value of band gap of g-C3N4/SnS2@SnO2 are approximately 2.35~2.60 eV.The effects of temperature,duration time,proportion,photocatalysis condition were optimized.It was found that the ratio of SnS2@SnO2 and g-C3N4(3:1)had a maximum rate constant 0.02475 min-1.Compared with pure g-C3N4 or SnS2@SnO2,photo-reaction rate of Cr(VI)on the as formedcompositecan be improved 39.7-and 5.9-time,respectively.The role of ethanol(0.2 mol L-1)as a hole scavenger in the reduction of Cr(VI)can effective remove toxic Cr(VI)ions via photo-reduction mechanism.Second,SrTiO3@Bi2O3 nanocomposites were synthesized by hydrothermal and high temperature calcination method.The photocatalytic activity in degradation different types of dye were also investigated under the illumination of UV and visible light.Different characterization testing technology showed that porosity of nanocomposite with narrow bandgap(2.1~3.1 eV).The composite with 30 wt% Bi2O3 content calcinated at 600 ?,5 h could photocatalytic degrade 50mgL-1RhB within 40 min under the exposure of Xe lamp(420 nm).Compared with photooxidization single MO solution(180 min),the photo-reaction rate can be improved 1-time after adding RhB solution,which may ascribed to dye sensitization.Finally,the effect of related synthesis condition variation such as temperature,duration time,titanium precursor on TiO2 photocatalysis properties were investigated.The results suggests that the material fabricated by Ti(OBu)4,TiCl4 processed higer photo-oxidization rate(10 mgL-1,60 min,100%),while the material degradation efficiency fabricated by TTIP reached 20%.There was no difference in photoredox Cr(VI)with the usage of the three types of titanium precursor.In addition,the effect of synthesis temperature on photocatalysis properties were also different when using different titanium precursor.