Optical properties and microstructure of Ni doped ZnAl2O4 nanopowders synthesized by sol–gel method

Abstract

Zn 1-x Ni x Al 2 O 4 (x = 0, 0.025, 0.05, 0.075, 0.10) nanopowders were successfully synthesized by solgel method, and the microstructure, morphology and optical properties were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), highresolution transmission electron microscopy (HRTEM), fourier transform infrared spectroscopy (FT-IR), diffuse reflectance spectroscopy (DRS) and photoluminescence spectra (PL). The experiment results show that all samples synthesized by this method possess spinel structure with good crystallization, no other impurity phase are observed, the morphology are dandruff-like. The band gap values of the Zn 1-x Ni x Al 2 O 4 samples are 4.02, 3.80, 3.70, 3.63 and 3.55 eV, respectively. The band gap of samples decreases with the increasing Ni doping concentration, and the PL spectra of the samples show the photoluminescence quenching.

Optical properties of Cr doped ZnAl2O4 nanoparticles with Spinel structure synthesized by hydrothermal method

“…pure ZnAl 2 O 4 exhibit the absorption peak in the wavelength range of 300-400 nm. Compared to pure ZnAl 2 O 4 , doped Zn 1−x Cr x Al 2 O 4 samples exhibit a broad absorption peak near 500 nm, which is the characteristic peak of Cr 3+ in the tetrahedral sites [36], this peak corresponds to the transition from 4 A 2 (F) to 2 A 1 (G) of 3d electron of Cr ion in the field of tetragonal crystal, and this peak causes the sample to appear greenblue [37]. With the increase of Cr concentration, the intensity of the absorption peak gradually increased.…”

Influence of pH tuning at the precursor-preparation process on the structural characteristics and catalytic performance of hydrothermally synthesized ZnAl2O4 nanoparticles

“…Zinc aluminate (ZnAl 2 O 4 ) is a stable material with a wide bandgap, and extensive research has been conducted regarding its use in photocatalysis [1,2] and as an ultraviolet laser source [1,[3][4][5][6][7]. In particular, nanoscale ZnAl 2 O 4 can potentially catalyze the degradation of NO x species [8] and dyes [1,2], as well as the steam reforming of ethanol [9,10].…”