Synthesis of Cu Doped ZnO Nanoparticles: Crystallographic, Optical, FTIR, Morphological and Photocatalytic Study

Abstract

Nanoparticles of Zn1−xCuxO system with nominal compositions x = 0.0, 0.01, 0.02 and 0.03 were prepared by co-precipitation method at room temperature. Structural, morphological, optical and chemical species of grown crystals were investigated by X-ray diffraction (XRD) technique, Scanning Electron Microscopy (SEM), UV-visible and FTIR spectroscopy, respectively. XRD analysis confirms that all samples have hexagonal structure with no impurity phases which suggest that Cu ion successfully incorporated into the regular ZnO crystal structure. The lattice parameters, volume of unit cell, X-ray density, atomic packing fraction, c/a ratio, and grain size were calculated from XRD pattern of pure and Cu doped ZnO samples and it was found that the grain size was in the range of 23 nm to 29 nm. The strain in pure and Cu doped ZnO samples was calculated by W-H analysis. Optical properties of Zn1−xCuxO samples were studied by using UV-vis spectrophotometer. Optical absorption spectra show that the band gap decreases with increasing Cu contents. The functional group and chemical interactions of Zn1−xCuxO samples were also determined at various peaks using FTIR data and observed that the functional groups corresponding to the Zn-O bands in the samples. The photocatalytic activities of the samples were investigated by oxidation of methylene blue under UV light illumination in batch reactor. The scavenger study was carried out to find out main reactive species responsible for the degradation of dyes.

Rapid, controllable, one‐pot and room‐temperature aqueous synthesis of ZnO:Cu nanoparticles by pulsed UV laser and its application for photocatalytic degradation of methyl orange

“…It can be seen that the absorption edge shows a clear red‐shift from 4.03 to 2.93 with the increase of Cu 2+ concentration. This decrease in energy band gap for ZnO:Cu NPs correspond to p‐d spin exchange interactions between the ZnO band electrons and the localized d electrons of doped Cu 2+ and have been observed in different reports . The PL intensity of the trap state emissions of ZnO NPs was quenched with the introduction of Cu impurity to the ZnO lattice, as shown in Figure (b) and a Cu‐related emission due to transition of electrons from trap states (I Zn ) to T 2 acceptor level appeared which showed a clearly red‐shift from 485 to 520 nm.…”

“…Fu et al reported 88% degradation of MO in the presence of ZnO:Cu NPs under 25 W UV lamp within 240 min. Mittal et al reported 78.8% degradation of crystal violet solution in the presence of ZnO:Cu NPs under 250 W mercury lamp within 3.5 h. Labhane and coworkers reported 60% degradation of methylene blue in the presence of ZnO:Cu NPs under 25 W UV lamp within 4.5 h. Moreover Cu‐doping does show a decrease in photocatalytic activities of doped NPs compared to undoped counterparts.…”

“…In most of these reports reaction temperature is high and reaction time is long . Moreover, Cu‐doping does not show considerable increase in photocatalytic activities of doped NPs compared to undoped counterparts . To the best of the authors’ knowledge, the current study presents the first report of the aqueous, room temperature synthesis of undoped and Cu‐doped ZnO NPs by pulsed UV laser.…”

“…Fu et al reported the synthesis of ZnO:Cu NPs by the sol‐gel method and evaluated photocatalytic activity of pure and doped NPs for degradation of methyl orange (MO) under a 25 W UV‐lamp. Labhane and coworkers synthesized Cu‐doped ZnO NPs by the co‐precipitation route and investigated their effect on degradation of methylene blue under UV illumination in batch reactor. Mittal et al used crystal violet dye under exposure of UV‐vis light irradiations as a test contaminant for studying photocatalytic activities of the ZnO and ZnO:Cu NPs synthesized by the co‐precipitation method.…”

“…Mittal et al used crystal violet dye under exposure of UV‐vis light irradiations as a test contaminant for studying photocatalytic activities of the ZnO and ZnO:Cu NPs synthesized by the co‐precipitation method. In most of these reports reaction temperature is high and reaction time is long . Moreover, Cu‐doping does not show considerable increase in photocatalytic activities of doped NPs compared to undoped counterparts .…”