Synthesis of ZnO Nanostructures for Low Temperature CO and UV Sensing

Muhammad Amin,Arshad Bhatti,Nazar Shah,Mohammad Islam,Umair Manzoor

doi:10.3390/s121013842

Muhammad Amin, Arshad Bhatti + Show 3 more

Open Access

https://doi.org/10.3390/s121013842

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Journal: Sensors	Publication Date: Oct 16, 2012
Citations: 53	License type: CC BY 4.0

Affiliation: COMSATS University Islamabad, King Saud University

Abstract

In this paper, synthesis and results of the low temperature sensing of carbon monoxide (CO) gas and room temperature UV sensors using one dimensional (1-D) ZnO nanostructures are presented. Comb-like structures, belts and rods, and needle-shaped nanobelts were synthesized by varying synthesis temperature using a vapor transport method. Needle-like ZnO nanobelts are unique as, according to our knowledge, there is no evidence of such morphology in previous literature. The structural, morphological and optical characterization was carried out using X-ray diffraction, scanning electron microscopy and diffused reflectance spectroscopy techniques. It was observed that the sensing response of comb-like structures for UV light was greater as compared to the other grown structures. Comb-like structure based gas sensors successfully detect CO at 75 °C while other structures did not show any response.

Highlights

Oxides are the basis of various smart and functional materials [1]
The results show good response to 200 ppm carbon monoxide (CO) gas at low operating temperatures
scanning electron microscopy (SEM) micrographs of zinc oxide (ZnO) nanostructures synthesized at different temperatures are shown in

Summary

Introduction

Oxides are the basis of various smart and functional materials [1]. Device fabrication using oxide semiconductors has gained significant importance, because physical properties of these oxides can be tuned. Method depends on many factors i.e., activation energy of crystallization, radius of catalyst droplets, super-saturation, synthesis temperature, volume of liquid droplets, and the equilibrium vapor pressure of the system. ZnO is a potential optical and gas sensor material due to its high sensitivity to toxic and combustible gases, carrier mobility, and good chemical and thermal stability at moderately high temperatures [7]. Systematic control of different ZnO nanostructural morphologies and their optical and sensing properties are presented. These ZnO nanostructures are promising materials for low-temperature, low-cost and high-performance gas sensors. The sensing properties of ZnO comb-like structures (without doping or surface modification) are unique as, to our knowledge, previously reported sensors all detect CO at relatively high temperatures

Experimental Section

Results and Discussion

Conclusions