Sr- and Ni-doping in ZnO nanorods synthesized by simple wet chemical method as excellent materials for CO and CO2 gas sensing

TL;DR

This study explores how Sr- and Ni-doping of ZnO nanorods improves their microstructural properties and enhances their effectiveness as sensors for CO and CO2 gases, indicating potential for indoor air quality monitoring.

Contribution

It introduces a simple wet chemical synthesis method for doped ZnO nanorods and demonstrates their superior gas sensing performance compared to pure ZnO.

Findings

Ni doping increases surface area and modifies nanorod morphology.

Doped ZnO sensors show higher response and lower operating temperature.

Both dopants enhance sensitivity and selectivity for CO and CO2 detection.

Abstract

In this study, the effect of Sr- and Ni-doping on microstructural, morphological and sensing properties of ZnO nanorods has been investigated. Nanorods with different Sr and Ni loadings were prepared using a simple wet chemical method and characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoluminescence (PL) analysis. XRD data confirmed that Sr- and Ni-doped samples maintainsthe wurtzite hexagonal structure of pure ZnO. However, unlikes Sr, Ni doping modifies the nanorod morphology, increases the surface area (SA) and decreases the ratio of IUV/Igreen photoluminescence peak to a greater extent. Sensing tests were performed on thick films resistive planar devices for monitoring CO and CO2, as indicators of indoor air quality.The effect of the operating temperature, nature and loading of dopant on the sensibility and selectivity of the fabricated sensors towards these two harmful gases were investigated. The gas sensing characteristics of Ni- and Sr-doped ZnO based sensors showed a remarkable enhancement (i. e. the response increased and shifted towards lower temperature for both gases) compared to ZnO-based one, demonstrating that these ZnO nanostructures are promising to fabricate sensor devices for monitoring indoor air quality.