Microwave pulse-assisted wet chemical synthesis of ZnO nanoparticles with excellent UV emission

Abstract

ZnO nanoparticles (ZNPs) were synthesized by wet chemical method using poly vinyl alcohol (PVA) templates. Uniform growth, high yield and excellent optical properties were observed in ZNPs synthesized under pulsed microwave irradiation (PMW). Moreover the dangling bonds of ZNPs prepared under PMW were passivated more effectively than in samples prepared without it. Strong UV emission peaks at ~ 360 nm and 380 nm, along with a feeble defect-related visible emission peak at ~ 465 nm, were observed in the room temperature (RT) photoluminescence (PL) spectra of ZNPs. Observation of two distinct excitonic peaks in RT UV-vis optical absorbance spectra and high UV-to-visible PL intensity ratio show high quality of ZNPs prepared by the present method. FTIR spectra were employed to explain the surface passivation mechanism of PVA.

Effective size control through solvents in microwave aided synthesis of GSH- CdTe quantum dots

“…So there is a quest for new, simpler and efficient synthetic routes with alternative solvents. Present study focuses on synthesis of size controlled CdTe QDs through a fast and facile MW [17] aided wet chemical route. Glutathione (GSH)-capped CdTe QDs (GSH-CdTe) were synthesized under mild conditions.…”

Pulsed Microwave Aided Morphology Controlled Synthesis of Nano Zinc Oxide

“…1. The basic growth unit is [Zn(OH) 4 ] 2-in the solution-based method to grow ZnO nano forms by the reaction of Zn+ ions with the OH-ions [8] further it is changed in ZnO. The crystal habit of wurtzite ZnO exhibits well-defined crystallographic faces such as polar-terminated (0001) and non-polar low-symmetry (1010).…”

“…Thus, the It can be observed that the morphology significantly depends on the molarity of precursor solution. Fig.2 2 and growth unit Zn (OH) 4 2-in aggregated form. The growth units of ZnO arrange themselves in water solvent, in presence of microwave irradiation pulse.…”

“…In this work, we have fabricated nanostructures through MW pulse assisted method. MW assisted methods have been considered as a powerful method for synthesis of highly crystalline, defect free nano particles with controlled size and shape [4]. This method is easy to handle, cost effective and less energy consuming, hence it is a green method.…”

“…The MW heating imparts very high energy uniformly, thereby generating numerous nucleation sites, responsible for high yield. Further the MW exposure time controls the morphology and size of the NPs [4]. So MW assisted co precipitation method was used for the present study.…”