| The photocatalytic oxidation technique have been paid more attention foradvantages of less energy cost, mild reaction conditions,easy operation,less secondarypollution, and so on. Recent years,cuprous become a hot spot of research ofphotocatalytic activity of ht semiconductor. Its narrow band gap (2.0eV) that can takefull advantage of sunlight in visible light.But its too narrow band gap also led to itshigh photo-electron-hole recombination rate and low photocatalytic activity. Therefore,it’s too important to improve the cuprous oxide’s photocatalytic research of the visiblelight activity.Paper prepared pure and modification cuprous oxide by chemical precipitation,use hydrazine hydrate as reducing agent; And take XRD、UV-VIS、FL、FT-IR、XPS、TG-DSC、 TEM systems characterize the samples.Methylene blue as the targetcompounds，Investigated the photocatalytic effect and rule of those samples;(1) Take CuSO4, NaOH as raw material, use hydrazine hydrate as reducing agent,prepared by chemical precipitation of pure Cu2O and N-Cu2O. By XRD we found thatthe particle size of nano-Cu2O is57.7nm, the N-Cu2O reduced14nm, now is43.7nm;the UV-VIS shows that the different doping Cu2O get blue shift, with gap widens,indicating that the N-Cu2O have stronger absorption of light at600~800nm; except thefluorescence intensity on a downward trend, the FL showed the spectrum level ofN-Cu2O is basically the same with Cu2O; from the FT-IR we can found the absorptionpeak of stretching vibration of N-Cu bond at1000-1250cm-1;The XPS proved that thenitrogen mix in the cuprous oxide’s lattice. As the temperature from0°C to1300°C,TG-DSC showed that the weight gain of Cu2O is12%, maybe have the cuprous oxidegenerated in the heating process, the desorption of Surface water and surface hydroxylgroups lead to weight loss45%of N-Cu2O; TEM shows that the crystal plane spacingof N-Cu2O is0.313nm.(2)The photocatalytic experiments were carried out by using Cu2O and N-Cu2O.The results showed that Cu2O has seldom significant photocatalytic effect onmethylene blue, but the photocatalytic effect obviously of N-Cu2O; the1.8%N-Cu2Othat the degradation of methylene blue can reach to73%is the best; with the initialconcentration of methylene blue40mg/L, the highest degradation rate is79.7%; everysolution50mL with catalyst0.2g, the degradation rate reach to94.5%; with illumination time increasing the degradation of methylene blue increased,4h later,therate can reach to94.5%,the exposure time maybe controlde in the4~5h; the Xenonlamp can induced N-Cu2O’s best catalytic activity. the rate is100%.(3) Take the same preparation as N-Cu2O to produce the Ce-Cu2O. By XRD wefound that the particle size of nano-Cu2O is57.7nm, the Ce-Cu2O increased7.4nm,now is65.1nm; the UV-VIS shows that the different doping Cu2O get blue shift, withgap widens, indicating that the Ce-Cu2O have stronger absorption of light at600~800nm; except the fluorescence intensity on a downward trend, the FL showedthe spectrum level of Ce-Cu2O is basically the same with Cu2O; from the FT-IR we canfound the absorption peak of stretching vibration of Ce-Cu bond at1100cm-1getincreased; the XPS proved that the cerium mix in the cuprous oxide’s lattice; as thetemperature from0°C to1300°C, TG-DSC showed that the weight loss of Ce-Cu2Ois70%, relatively stable at200℃; TEM shows that the crystal plane spacing ofCe-Cu2O is0.312nm.(4) The photocatalytic experiments were carried out by using Ce-Cu2O. Theresults showed that Ce-Cu2O has a significant photocatalytic effect on methylene blue,1.5%Ce-Cu2O that the degradation of methylene blue can reach to70%is the best;with the initial concentration of methylene blue20mg/L, the highest degradation rateis72.6%; every solution50mL with catalyst0.05g, the degradation rate reach to85%;with illumination time increasing the degradation of methylene blue increased,3.5hlater, the rate can reach to86%,the exposure time maybe controled above3.5h; thatthe degradation rate of Fluorescent lamp can reach to the best is86.6%. |
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