The Preparation And Properties Of Zn_1-xCd_xS And Its Composites

In recent years, with the development of industry, a large amount of industrial waste water, waste gas and automobile exhaust is released, and thus environmental pollution becomes increasingly serious. Therefore, it is imperative to deal with organics in the waste water.In this work, we discussed the traditional methods for wastewater treatment and find that photocatalytic degradation is the best way to solve environmental problem through the comparison of the various methods. In addition, because of its suitable band gap, Zn1-xCdxS has become a promising semiconductor photocatalyst. In the end, compared with other methods, the combustion method has many advantages, such as no need for expensive equipment, fast heating rate, short reaction time and energy-saving.The Zn1-xCdxS nanomaterials were prepared by combustion method. Moreover, in order to solve the difficulty in recycling of photocatalyst we synthesized the magnetic Zn1-xCdxS/γ-Fe2O3 composites. In addition, due to the high surface of GO, it was used as the carrier of Zn1-xCdxS. And we prepared the Zn1-xCdxS composites with more excellent photocatalytic performance. Their physicochemical properties were characterized by XRD, SEM, TEM, PL, Raman, VSM, FTIR and UV-vis, and the catalytic properties were investigated through degradation of methylene blue. Based on the above content, following researches were carried out:(1) Zn1-xCdxS(x =0- 1.0) were prepared by a combustion method using cadmium nitrate, zinc nitrate and thiourea as raw material. These materials were heated on an electric jacket until the precursor solution was obtained, then calcined under 300 ℃. Through changing the content of Cd, a series of Zn1-xCdxS were prepared successfully. In this part, we discuss the influence of Cd on the structure, morphology and the photocatalytic performance.(2) The magnetic Zn1-xCdxS/γ-Fe2O3 composites were successfully synthesized via a combustion method, using nitrate(cadmium nitrate, zinc nitrate and iron nitrate) as oxidizer, thiourea and citric acid as fuel. We discussed the influence of Cd content on the structure and the performance of the samples. Finally, the photocatalytic mechanism of Cd S/γ-Fe2O3 was discussed.(3) Combustion synthesis of Zn1-xCdxS/r GO composites was successfully synthesized via a combustion method, using cadmium nitrate, zinc nitrate, thiourea and graphene oxide as raw materials. After heated on an electric jacket, the precursor solution was calcinated under 300 ℃. Through changing the content of Cd, a series of Zn1-xCdxS/r GO composites were prepared successfully. In this part, we discuss the influences of Cd concentration on the structure, photoluminescence and the photocatalytic performance.of the prepared samples. Fianlly, we analyse the photocatalytic mechanism of Cd S/r GO.