Synthesis, structural and optical properties of pure ZnO and Co doped ZnO nanoparticles prepared by the co-precipitation method

Abstract

Pure ZnO and Cobalt (Co) doped ZnO nanoparticles (NPs) were synthesized by the co-precipitation method. The synthesized nanoparticles retained the wurtzite hexagonal structure, which was confirmed by X-ray diffraction studies. From FESEM studies, ZnO and Co doped ZnO NPs showed Spherical and nanorod mixed phase and Spherical like morphology, respectively. The amount of dopant (Co 2? ) incorporated into ZnO sample was determined by EDAX. The FT-IR spectra confirmed the Zn-O stretching bands at 438 and 427 cm -1 for ZnO and Co doped ZnO NPs. From the UV-VIS spectroscopic measurements, the excitonic pecks were found around 376 and 370 nm for the respective samples. The photoluminescence measurements revealed that the broad emission was composed of seven different bands due to zinc vacancies, oxygen vacancies and surface defects. The dynamic light scattering (DLS) and Zeta potential measurements were used to find out the size and surface charges.

Structure, morphology and luminescence properties of sol-gel method synthesized pure and Ag-doped ZnO nanoparticles

“…The figure 3 shows the average particle sizes of pure ZnO and Ag-doped ZnO as 18 nm and 19 nm respectively. The identical result is conformed in the XRD pattern [17][18][19]. Thus a good correlation is found among the results of XRD, SEM, DLS techniques is found in the experiment based on the similarity in size of nanoparticles, which ranges within 18 nm to 24 nm.…”

“…The small particle size confirms the potential stability of the nanoparticles, i.e., the solution will resist the aggregation. The low ςpotential leads to repulsion rather than attraction and thus the dispersion will break and flocculate as demonstrated in references [17,36].…”

Assessment of synthesis approaches for tuning the photocatalytic property of ZnO nanoparticles

“…Additionally, the intensity of orange-red emission is stronger for Z-01 as compared to Z-02. This indicates that relatively more oxygen interstitials are present in Z-01 than Z-02 [50]. A small hump in the green emission region observed in both the samples represent recombination of a shallowly trapped electron with a deeply trapped hole at valence band of Zn and oxygen interstitials [51].…”

“…5b, corresponds to the singly ionised Zn vacancies [52]. This figure shows the existence of two bluegreen emission bands (or weak green emission) at 484 nm and 494 nm, which may be attributed to the transition between oxygen vacancy and oxygen interstitial defects [50]. The presence of such multiple peaks in the visible region is typical for ZnO NPs [53].…”

Effect of Eu doping on the structure, morphology and luminescence properties of ZnO submicron rod for white LED applications

“…The structure, morphology and properties of semiconductor materials are bound not only to precursor materials and preparation methods, but also to dopants and annealing temperatures [4][5][6]. Among the semiconductor materials, ZnO with a wide band gap (3.37 eV) is an II-VI semiconductor and it has a large exciton binding energy of 60 meV [7][8][9][10]. ZnO exhibits excellent physical and chemical properties which make it a unique host material for numerous devices by doping with different rare earth ions.…”