| ZnO has many advantages,including low price,high stability,non-toxic environmental protection and so on.However,ZnO also has some defects,such as only responding to ultraviolet light,high photoelectron-hole composite rate,photocatalytic process accompanied by photocorrosion,etc.In order to solve these problems,a large number of scholars have done a lot of research to explore the modification of ZnO,among which semiconductor composite is an effective photocatalyst modification method.CeO2 is a stable rare earth metal oxide with strong oxygen storage capacity and good photocatalytic performance and anti-photocorrosion ability.The composite of CeO2 and ZnO to prepare CeO2/ZnO composite material can effectively promote the separation of photoelectron-hole and improve the photocatalytic activity of the material.In the process of exploring the photocatalytic mechanism of CeO2/ZnO composite material,it was found that the introduction of Ag could further improve the photocatalytic performance of CeO2/ZnO composite material.Noble metal doped semiconductor can better promote the photocarrier separation,which not only inhibits the effective electron and hole recombination,but also further inhibits the photocorrosion of ZnO,so that the photocatalytic activity and stability can be significantly improved.GO is an excellent carrier material with two-dimensional plane structure,with excellent electron conductivity and large specific surface area.CeO2/ZnO and GO are further combined to prepare CeO2/ZnO/GO composite material,which is more conducive to the migration and separation of photocarriers,and further improves the photocatalytic performance of composite semiconductor.The research contents of this paper are as follows:Using ultrasonic of ZnO/CeO2 composite materials prepared by microwave,Ag doped ZnO/CeO2 composite materials,CeO2/ZnO/GO composites,Methods such as XRD,SEM,BET,TEM,PL were used to characterize the preparation of the materials were characterized,and through the visible light degradation of AF to evaluate the photocatalytic properties of the samples.(1)ZnO is a flower-shaped spherical structure formed by interpenetration of nano-sheets,and its surface is attached with nano-CeO2 particles with good dispersion.ZnO/CeO2 composite photocatalyst with a molar ratio of 20:1 showed good photocatalytic activity under visible light,and the photodegradation rate of AF reached 96.44% after 90 min of light,which was significantly higher than that of pure phase ZnO and CeO2.The stability of ZnO/CeO2 was good,and the photodegradation rate of AF was still 93.53% after 6 uses.Mechanism studies have found that ·O2-is the main active species in photocatalytic degradation of AF.(2)The doping of Ag has an influence on the morphology of ZnO.With the continuous increase of Ag doping in THE CeO2/ZnO composite material,the spherical structure of ZnO gradually disperses and breaks down into thin sheets.When the Comtent of Ag in the composite was 1%,the photodegradation effect of Ag doped CeO2/ZnO composite photocatalyst was the highest,indicating that the degradation rate of AF reached 98.83% after 90 min of light.(3)The absorption edge of CeO2/ZnO/ GO composite photocatalyst is significantly redshifted compared with that of CeO2/ZnO composite photocatalyst,and the absorption intensity in the visible region is greatly improved.The CeO2/ZnO/GO composite photocatalyst prepared under the condition of adding 4 wt%GO had the highest photocatalytic activity,and the degradation rate of AF reached99.30% after 90 min of visible light irradiation.Compound ZnO and CeO2,and further modify the photocatalyst by means of doping and loading,effectively improve the photocatalytic performance of the photocatalyst,and extend the spectrum available to the visible region of the photocatalyst,improve the utilization ratio of the photocatalytic material to sunlight,with good stability. |
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