Zinc Oxide–Nanoclinoptilolite as a Superior Catalyst for Visible Photo-Oxidation of Dyes and Green Synthesis of Pyrazole Derivatives

Abstract

In this study a new ZnO doped nanoclinoptilolite was synthesized and the morphology and properties of this new nanocomposite were studied using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Field emission scanning electron microscopy (FESEM). The effective substance (ZnO) amount on clinoptilolite substrate was also determined by EDX method. Natural based nanocomposites are low cost and high efficient materials for photo oxidation of organic dyes and also synthesis of organic compounds. The ability of this new nanocomposite in photodegradation of methylene blue (MB) as a cationic dye and mixture cationic- anionic dyes (methylene blue and methyl red) under visible light irradiation was studied. The effect of various important factors on the degradation rate was studied. Under optimal conditions, the degradation efficiency of MB was achieved about 88% in 40 min. A first order kinetic was observed for the degradation of MB. Also, this nanocomposite was used as an ecofriendly and green nanocatalyst for the synthesis of pyrazole derivatives by condensation of substituted phenyl hydrazines with 1,3-diketone/ketoester with high performance. The reaction of synthesis of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one (3a) in aqueous medium gave the required product in high yield (99%) and in shorter reaction time (10 min).