Preparation Of The Cds-NaTaO3Composite And Study On Photo-degradating Pollutants

Tantalum has a broad application in many different fields due to their higher stability, lesslight and chemical corrosion, safety, and nontoxicity. Many organic pollutants can be degradedby their photogenerated electrons and holes with a strong enough performance of the reductionas well as oxidation. However the obvious shortcomings is they can only excited by ultravioletlight due to the wider band gap which may leads to the lower light absorbance in the solarspectrum. It is known that by compositing two different structure semiconductors, the compositemay become a well photocatalyst with a better catalytic activity and stability than any singlesemiconductor. Moreover, the visible light corresponding can also be greatly improved.Moreover, the photocatalytic efficiency can be controlled by turning the rate of the compositefor the two different semiconductors. The energy band gap can be controlled by Synergisticeffect of the semiconductor with the suitable band structure. Thus it is meaningful research topicto study the composite of tantalite and the semiconsector with the narrow band gap. It has beenfound CdS is a semiconductor with a narrow band gap and the electron in valence band can beexcited to the conduct band by visible light. Thus by compositing CdS and NaTaO3, thephotocatalyst may have the high ability of reduction and oxidation, as well as the wide responsefor solar light.In this paper, the composite CdS-NaTaO3was synthesized by Hydrothermal andmicrowave method with a series of rate. The Optimization Synthetic route and reactiveconditions were investigated. Furthermore, the detection methods of the elements in tantalatewere studied. The photocatalytic activity and the influencing factors were studied by degradingorganic pollutants. It was found that the composite CdS-NaTaO3synthesized by Hydrothermalmethod at180℃with a ratio of1:3has best photocatalytic activity for the degradation of MBwhile the composite CdS-NaTaO3by microwave method at160℃with a ratio of1:5have bestphotocatalytic activity for the degradation of MB. Furthermore, we found that the compositeCdS-NaTaO3synthesized by Hydrothermal method at150℃with a ratio of1:5has bestphotocatalytic activity for the degradation of Rhodamine B while the composite CdS-NaTaO3bymicrowave method at140℃with a ratio of1:5have best photocatalytic activity for thedegradation of Rhodamine B. the photo-degraded activities of Methyl blue and Rhodamine B for the photocatalyst by compositing two different semiconductor are obviously better than anysingle conductor. The results indicated that the Uniform Heterojunction has been formed by thetwo semiconductors.