Synthesis and characterisation of spherical core-shell Ag/ZnO nanocomposites using single and two – steps ultrasonic spray pyrolysis (USP)

Abstract

Synthesis and characterisation of spherical core-shell Ag/ZnO nanocomposites using single and two -steps ultrasonic spray pyrolysis (USP)

Tuning the Morphology of ZnO Nanostructures with the Ultrasonic Spray Pyrolysis Process

“…that the decomposition of zinc nitrate hexahydrate into zinc oxide takes place via step-wise reaction with the formation of a Zn(NO3)2·2Zn(OH)2 intermediate compound. However, before the decomposition takes place, the initial salts melt and reaction takes place in the liquid phase [17,18]. Since particle formation in the melt phase is driven by nucleation and growth processes, the final morphology can be adjusted by controlling nucleation and growth rates via process parameters.…”

“…The formed aerosol was transferred into a one-step USP device to the pre-heated furnace (Nabertherm, R 50/250/12, Lilienthal, Germany) through a quartz tube (0.7 m length and 0.02 m diameter) using N 2 gas. The experiments were conducted with 0.5 L/min and 0.75 L/min N 2 flow rate at 400, 600 and 800 • C reaction temperature for 3 h. The thermal decomposition of Zn(NO 3 ) 2 ·6H 2 O under air atmosphere during the spray pyrolysis has been reported previously [17,18]. The chemical balance equations were given in 3 reaction steps:…”

“…There have already been some studies reported, that control ZnO morphology by wet chemical methods is possible; however, these used reactant agents, such as polyethylene glycol (PEG) and cetyltrimethylammonium bromide (CTAB). In our previous study focusing on Ag/ZnO core shell nanostructured materials for photocatalytic applications, under some synthesis conditions, variation from the typical spherical morphology Ultrasonic Spray Pyrolysis (USP) into entangled plates was observed in ZnO particles without any additives [17]. These findings raised the question of whether it is possible to tune ZnO particles morphology by the USP process with simplicity, good process control, high flexibility, and good scale-up potential, without any additives, obtaining high-purity products [17].…”

“…In our previous study focusing on Ag/ZnO core shell nanostructured materials for photocatalytic applications, under some synthesis conditions, variation from the typical spherical morphology Ultrasonic Spray Pyrolysis (USP) into entangled plates was observed in ZnO particles without any additives [17]. These findings raised the question of whether it is possible to tune ZnO particles morphology by the USP process with simplicity, good process control, high flexibility, and good scale-up potential, without any additives, obtaining high-purity products [17]. For this purpose, varying influential USP process parameters like Zn(NO 3 ) 2 ·6H 2 O concentration in the initial solution, carrier gas (N 2 ) flow rate and reaction temperature (400-800 • C) were examined.…”

Plasmon enhanced luminescence in hierarchically structured Ag@ (Y0.95Eu0.05)2O3 nanocomposites synthesized by ultrasonic spray pyrolysis

“…Similarly, Rabanal et al investigated Ag@Y 2 O 3 :Eu (9 at. %) nanocomposites synthesized by ultrasonic spray pyrolysis (USP) and reported enhancement at lower Ag concentrations and worsening at higher Ag concentration [18].…”