Synthesis of ZnO nanoparticles by co-precipitation technique and characterize the structural and optical properties of these nanoparticles

Abstract

The present work demonstrates synthesis and study of physical properties of chemically synthesized ZnO nanoparticles by co-precipitation technique. Detailed synthesis procedure had been described in the experimental section. Chemically synthesized ZnO samples were annealed at 300°C and 500°C. These samples have been characterized by doing X-Ray diffraction (XRD), photoluminescence (PL) and Raman spectroscopy. XRD patterns indicate wurzite structure of these samples. SEM pictures shows growth of grain size with annealing temperature treatment. The lattice parameters (a & c) of ZnO samples are showing increasing tendency with annealing treatment. PL spectra with excitation wavelength : λex=330 nm exhibit a broad and asymmetric UV band centred around 386 nm (~ 3.212 eV) and 390 nm (~ 3.179 eV) respectively for the 300°C and 500°C annealed samples. Broad UV emission band indicating that, it has defect related origin. The Raman spectra of these samples indicate that intensity of Raman peaks improves with annealing at the higher temperature. Possibly high temperature annealing (500°C) brings modification into the micro-structure. The micro-structure and optical properties of these synthesized samples are compared with that of pure ZnO powder samples. Finally correlation between structural and optical properties has been made based on the analysis of experimental data.

Photocatalytic Degradation of Crystal Violet (CV) Dye over Metal Oxide (MOx) Catalysts

“…The specific interactions present at each peak are summarized in Table 2. The Raman spectra of TiO 2 and ZnO are like previous studies' results [44,49,53,54].…”

“…Based on the peak positions and relative peak intensity, it is confirmed that the tested TiO 2 contains the anatase phase [45][46][47][48]. In the case of ZnO, there are peaks at 102 (s), 333 (w), 439 (s), 586 (w), and 667 (w), which are assigned to the E 2 (LO), E 2 (LO)-E 2 (H), E 2 (H), E 1 (LO), and E 2 (LO)-E 2 (H) modes of Zincite, respectively [49][50][51][52]. The specific interactions present at each peak are summarized in Table 2.…”

Effect of Co Doping on the Physical Properties and Organic Pollutant Photodegradation Efficiency of ZnO Nanoparticles for Environmental Applications

“…Another vibrational mode at 618 cm −1 , observed for the Zn 0.95 Co 0.05 O composition, is the Co doping effect and is attributed to the F 2g vibrational mode characteristic of ZnCo 2 O 4 . The peak at around 572 cm −1 is due to the A 1 (LO) mode and is linked to the structural disorder in the host lattice, including oxygen vacancy (V O ), zinc interstitial (Zn i ), and their complexes [ 42 , 43 , 44 , 45 ]. An observed change in the intensity of this peak, particularly for the Zn 0.95 Co 0.05 O composition, suggests an increased concentration of oxygen vacancies in this specific composition due to cobalt addition.…”

High Preferred Orientation on c-axis of ZnO:GO Crystal Film Synthesized Under Electric Field

“…The structural characteristics, such as interplanar spacing d(002) and lattice parameters c, were calculated using equations ( 2) and (3). Since the peak was highly dominantly of the (002) plane, the lattice parameters a was determined using the ratio between c and a, (c/a) = 1.633, that specific value of ZnO hexagonal wurtzite structure [32]. The dislocation density (𝛿) represents the number of defect states as dislocation lines in the crystallite grain (nm -2 ).…”