شماره ركورد كنفرانس :
4183
عنوان مقاله :
Visible light photocatalytic activity of ZnS and CdS nanoparticles affecting by coating
پديدآورندگان :
Soltani Nayereh nayereh.soltani@gmail.com Shahr-e-Qods Branch, Islamic Azad University , Zare Mohammad Reza Majlesi Branch, Islamic Azad University , Bahrami Afarin afarin.bah@gmail.com Islamshahr Branch, Islamic Azad University , Behzad Kasra kasrabehzad.ac@gmail.com Shahr-e-Qods Branch, Islamic Azad University
كليدواژه :
ZnS and CdS nanoparticles , Photocatalysis , Visible light
عنوان كنفرانس :
اولين همايش ملي فناوري نانو
چكيده فارسي :
Photocatalyticoxidation of organic and biological molecules is one of the most efficient methods for alleviating the negative environmental impact of hazardous wastes and toxic pollutants in aqueous media. The superiority of photocatalytic technique in wastewater treatment is due to its advantages over the traditional techniques such as quick oxidation, high efficiency, no formation of polycyclic products and oxidation of pollutants in the low levels [1].The process of photocatalysisis based on electron–hole pairs created in semiconductor materials by the absorption of photons, which can further generate free radicals such as hydroxyl in the system to redox the compounds absorbed on the surface of a photocatalyst. The use of solar irradiation to energize photocatalyst materials is environmentally appealing which permits the design of a simple, robust and inexpensive water treatment setup [2].
In the present work, we have attempted to provide improvement in visible light photocatalytic activity of microwave synthesized ZnS and CdS nanoparticles via coating their surface by organic or inorganic materials. Microwave irradiation method is a facile and effective synthetic strategy to produce high purity perfect nanocrystals under mild conditions at reasonable cost and environmentally friendly [1]. The organic passivation of nanoparticles was performed using a water dispersible polymer, polyvinyl pyrrolidone (PVP), in a one pot reaction. For the inorganic passivation of ZnS and CdS nanoparticles, a layer of given thickness of CdS and ZnS, respectively, have been deposited on the surface of nanoparticles using a two steps synthesis procedure. The obtained nanocompositeswere characterized with several routine techniques and their photocatalytic performance was studied and compared by employing the photodegradation of methylene blue (MB) under visible light irradiation in terms of degradation efficiency and kinetic rate constant of photocatalysis.
