Synthesis of Na doped ZnO nano-particles for detection of reducing gases

Abstract

This paper proposed a very facile method for 1 wt% Na doped Zinc Oxide (Na-ZnO) nanoparticles which have been synthesized through sol-gel method. These prepared nanoparticles have been characterized using scanning electron microscope (SEM), and Energy Dispersive Spectroscopy (EDS). Morphology of the film was analyzed by SEM which depicts the clustering of the nanoparticles which were calcined at 600 °C for 2 hr. and on other side Na doping in the ZnO nano-particles is validated by the EDS of the film having two major energy peaks for Zn and Na element. These synthesized nanoparticles are further used for fabrication of chemiresistor by drop casting method using methanol solvent. The pre-patterned gold electrode over alumina substrate is used to investigate the gas sensing capabilities of Na doped ZnO nanoparticles towards reducing gases such as H2, CO, LPG, ethanol, propanol etc. and also measured the transient response of the chemi-resistor toward ethanol gas. This chemi-resistor shows the remarkable sensing capability (∼72% sensitivity) with quick response (∼20 sec) and recovery time (∼50 sec) of ethanol gas at 3333 ppm concentration. Transient response of chemi-resistor with the exposure of ethanol gas shows the linear escalation in the sensitivity (from 11.76 to 72%) with the concentrations ranging from 833 to 3333 ppm. © 2016 IEEE.