novel of zno/zrcnp nanocomposite : excellent visible- light – photocatalytic performance for the degradation of organic pollutant

In recent years with the rapid prompt of the worldwide population and the continuous expansion of industrial manufacture, how to handle water pollution has became a serious research topic. accordingly several treatment procces have been studied, specifically advanced oxidation processes (aops), sonolysis, photolysis and fenton process, ozonation and electrochemical oxidation. among a variety of methods to treat dye-pollute water, photocatalytic degradation has due to an environmental-friendly technology obtain more attention as a usefull method for treating the colored water. photocatalyst has the main factor in photocatalysis technology; currently semiconductor metaloxides (tior2r, zno, etc), noble metals (au, ag, etc.) and metal chalcogenides (zns, mos2,ws2) have attracted a great deal of attention owing to their specific photocatalytic properties. zno, as a semiconductor, has be awarded wide consideration because of its high surface reactivity,high photo-sensitivity, being friendly to the environment, low price, and chemical stability. accordingly zno is also usually used as photocatalyst to degradation processes the organic pollutants in water or air. in spite of its high potentiality, the photocatalytic efficiency of zno is low due to fast recombination of photogenerated electon–hole (e-h) pairs. one of methods to suppress e–h recombination to improving the photocatalaytic activityac and tailoring more effective photocatalysts has coupling two or more semiconductors to form a semiconductor/semiconductor heterojunctions[1,2]. in this study, first zrc nanoparticles (zrcnp) were successfully synthesized via a combined sol–gel and carbothermal hydrothermal process, then zno nanoparticles attached to the zrcnp. the synthesized composite (zno/zrcnp) showed an enhanced photocatalytic activity over the degradation of rhodamine b compared to zno and zrc under visible-light irradiation. the zno and zrc have a bandgap of about 3.2 and 0.4ev respectively. therefore, the band gap for zno/zrcnp system is predict to be reduced, which leads to an increase absorption edge visible range. the results showed that the degradation rate under visible light irradiation was 91% in 150 min, and the photocatalytic performance of the zno/zrcnp was approaching ~4 times higher than that of the bare zno nanoparticles (24%).