Preparation and characterizations of CuO doped ZnO nano-structure for the photocatalytic degradation of 4-chlorophenol under visible light

سال انتشار: 1395
نوع سند: مقاله ژورنالی
زبان: انگلیسی
مشاهده: 424

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شناسه ملی سند علمی:

JR_AET-2-1_002

تاریخ نمایه سازی: 21 فروردین 1397

چکیده مقاله:

In the present investigation, a ZnO nanostructure was synthesized by means ofprecipitation and sonochemical methods. The X-ray diffraction (XRD) patternindicated that the wurtzite structure of ZnO had a hexagonal symmetry and therewas no impurity. The average ZnO particles crystallite size was calculated at about 41nm. The SEM and TEM images revealed nanostructure ZnO particles with acauliflower-like and rod morphology with dimensions of 85, 79 and 117 nm. In orderto investigate the increment of ZnO photoactivity under visible light, the CuO dopedZnO nanostructures were fabricated by a wet impregnation method using copperoxide as the copper source and ZnO as the precursor. The XRD analysis confirmedthat the CuO phase was present in the as-prepared sample and the average size ofnano crystalline decreased to about 36 nm. The DRS spectra indicated the extendedabsorption of CuO-ZnO to the visible range as a result of band gap reduction to 2.9 eV(in comparison of 3.2 eV in ZnO). In order to investigate the photocatalytic activity ofthe synthesized photocatalyst, the degradation of 4-Chlorophenol under visible lightwas performed. Sixteen experiments using full factorial were executed by adjustingfour parameters (amount of catalyst, initial concentration of 4-Chlorophenol, pH, andtime of irradiation). An empirical expression was proposed and successfully used tomodel the photocatalytic process with a high correlation, and an optimalexperimental region was also obtained. According to the developed model fordegradation and the subsequent ANOVA test using Design Expert software, the timeof irradiation with a 46.57% effect played the most important role in thephotocatalytic activity, while the influences of parameters on each other werenegligible. Optimal experimental conditions for 4-Chlorophenol concentration(0.01 g/L) were found at an initial pH =8 and a catalyst loading of 0.07 g/L. The resultsindicated that CuO-ZnO can remove 95% of 4-chlorophenol from water under optimalconditions.

نویسندگان

Afsaneh Shokri

Faculty of Chemical, Petroleum, and Gas Engineering, Semnan University, Semnan, Iran