Low-cost synthesis of AuNPs through ultrasonic spray pyrolysis

Abstract

The present research informs about the synthesis of gold nanoparticles (AuNPs) through Ultrasonic Spray Pyrolysis (USP), which were collected in ethanol with 0.1% Polyvinylpyrrolidone (PVP). Initially, the research focused on two precursors, where the first represented a homemade H-HAuCl _4 , completed in our own laboratory through the chlorine gas method by using HCl and KMnO _4 , and the second was the commercial C-HAuCl _4 , prepared by using Gold (III) chloride tetrahydrate powder and deionised water. The goal was to find any potential precursor differences and their influences on the later use for AuNPs synthesis through USP using almost the same parameters. In the first step of research it was determined that the H-HAuCl _4 precursor was similar to C-HAuCl _4 in chemical composition, surface tension and pH value. This finding represented the starting point for being able to use H-HAuCl _4 in the USP for AuNPs‘ synthesis. In the second step, AuNPs were synthesised from both types of precursors. Afterwards, characterisation of some functional properties by FTIR and UV–vis techniques was done directly for H- and C-AuNPs in the collecting media. For SEM/EDX and TEM microscopy both types of H- and C-AuNPs were dried, and observation revealed that the morphology, shape and size distribution of dried AuNPs were very similar. Based on the performed laboratory research, it could be concluded that prepared H-AuNPs could represent a new and low-cost effective solution for future USP transfer onto the industrial level, not only in in the process itself, but also in the field of Low-cost Precursor Preparation.

Keywords

• ultrasonic spray pyrolysis
• gold chloride precursors
• gold nanoparticles
• characterisation
• properties