Synthesis from zinc oxalate, growth mechanism and optical properties of ZnO nano/micro structures

Abstract

We report the synthesis of various morphological micro to nano structured zinc oxide crystals via simple precipitation technique. The growth mechanisms of the zinc oxide nanostructures such as snowflake, rose, platelets, porous pyramid and rectangular shapes were studied in detail under various growth conditions. The precursor powders were prepared using several zinc counter ions such as chloride, nitrate and sulphate along with oxalic acid as a precipitating agent. The precursors were decomposed by heating in air resulting in the formation of different shapes of zinc oxide crystals. Variations in ZnO nanostructural shapes were possibly due to the counter ion effect. Sulphate counter ion led to unusual rose-shape morphology. Strong ultrasonic treatment on ZnO rose shows that it was formed by irregular arrangement of micro to nano size hexagonal zinc oxide platelets. The X-ray diffraction studies confirmed the wurzite structure of all zinc oxide samples synthesized using different zinc counter ions. Functional groups of the zinc oxalate precursor and zinc oxide were identified using micro Raman studies. The blue light emission spectra of the various morphologies were recorded using luminescence spectrometer.

Structural study and phase transition investigation in a simple synthesis of porous architected-ZnO nanopowder

“…The first four oxygen anions are located at two similar distances from the central zinc atom (Fig. 4), which are attributed to metal-oxygen stretching vibrations and are in good agreement with previous reports [34].…”

A valence states approach for luminescence enhancement by low dopant concentration in Eu-doped ZnO nanoparticles

“…4a) obtained on the precursor powder provides a direct observation of the morphological and structural characteristics. The precursor powder consists in agglomerated nanocrystalline particles, this behavior being characteristic for the oxalate-type precursors [21,37,47,48]. The high-resolution pattern (Fig.…”

“…Different synthesis methods, such as solid-state reaction [18], coprecipitation [19][20][21], sol-gel [22][23][24], hydrothermal [25][26][27], pyrosol [28,29], microemulsion [30][31][32], combustion [13], and electrochemical methods [33,34] have been used in order to obtain the europium-doped zinc oxide nanoparticles. The precipitation/coprecipitation method, as compared to other chemical or physical methods, is an inexpensive method which allows the synthesis of a wide range of nanoparticles with different and controlled sizes and shapes [19,20,[35][36][37].…”

Structural, optical and photocatalytic properties of zinc oxides obtained from spent alkaline batteries

“…According to Raj et al [7], the synthesis of ZnO by using precipitation methods has a low cost, and the production of nano oxides with different sizes and shapes is reproducible.…”