| Semiconductor photocatalysis has its own unique characteristics and advantages,such as non-toxic and harmless, no pollution to the environment, the good stability andcan be recycled repeatedly, improving the efficiency of recycling. Therefore the functionof photocatalytic degradation for semiconductor has extensive application in environ-mental pollution treatment, including wastewater treatment, reduction of heavy metals,and air purification. Transition metal oxides and mixed oxides are the most common ma-terials in the current photocatalytic field. Many highly reactive compounds are fruitful interms of environmental management and pollution degradation. Due to its excellent opti-cal and electrical performance, ZnO won the favour of the researchers.The internal and surface defects of ZnO which can affect its band and change thecrystal structure, will affect the photocatalytic property of the ZnO materials. In additionthe particle size, morphology can also affect its catalytic degradation ability. As a result,much research work have been done to the crystal structure, intrinsic and introducing de-fects of ZnO. Element doping has been considered to be a effective method to adjust theenergy band, crystal structure, and defects, finally to improve the photocatalytic perfor-mance.At first, we prepared the pure ZnO powders respectively through the hydrothermalmethod and sol-gel method in this paper. The sample prepared by the hydrothermal me-thod is anisotropic, having very good photocatalytic performance. More defects are in-troduced and the high intensity of visible light emission in the visible light region couldbe found. The sample prepared by the sol-gel method has good ultraviolet luminescenceperformance, and high quality of crystallization, could be used in Uv laser equipments.The sol-gel method is simple to operate and easy to control, has less side effects, anddoes not need expensive equipment, so it has the potential to realize the industrializedproduction. On this basis, we chose the the sol-gel method to synthesis the Nd-doped ZnO (Zn0.97Nd0.03O) and the Eu-doped ZnO (Zn0.97Eu0.03O), which realized the adjust-ment to the band gap and crystal structure. Nd-doping obviously improves the photocata-lytic degradation performance of the sample, and the Eu-doping improves the perfor-mance of ultraviolet light-emitting.Considering that the photocatalytic performance of the sample prepared by hydro-thermal method is better than the sol-gel method, while the effect of Nd-doping is supe-rior to Eu-doping, we prepared the Zn1-xNdxO（x=0.01,0.03,0.05）samples to get moreefficient catalyst. The intensity of the DL emission reaches maximum at the concentra-tion of x=0.03, which is about21.8times of the UV emission. The enhanced visibleemission can be explained by the induced defects like antisite oxygen OZnand interstitialoxygen Oi. The doping of Nd increases the electron-hole pairs.Allow for that Nd-doping can enhance the visible emission, while Eu-doping can getthe ultraviolet light emission improved, we hope to realize the improve both of the visibleemission and the Uv emission by doping the two kinds element together. Because no so-lution was dumped in the sol-gel experiment process, and the highest temperature wasonly130℃, while the hydrothermal method was relatively difficult to control for mul-tiple elements doping, so we chose the sol-gel process to synthesis Eu-Nd co-dopingsample(Zn0.97-xEu0.03NdxO). The two elements in doping system can realize the superpo-sition of the different effects and realize the adjustment of the optical property. |
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