Highly selective and sensitive xylene gas sensor fabricated from NiO/NiCr2O4 p-p nanoparticles

By Hongyu Gao, Jie Guo, Yiwen Li, Chang Xie, Xiao Li, Long Liu, Yi Chen, P. Sun, Fangmeng Liu, Xu Yan and 2 more. Sensors and actuators. B, Chemical, 2019

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Abstract Xylene is a harmful and hazardous volatile organic compound (VOC) indoors, thus selective and sensitive detection for subppm-level xylene is crucial, however a remained challenge. In this work, p-NiO/p-NiCr2O4 nanocomposites were successfully synthesized through a simple hydrothermal route and used as sensing materials. In the comparative gas sensing test, the sensor fabricated from NiO/NiCr2O4 (Cr/Ni = 25 at%) nanocomposite exhibited the highest response (66.2–100 ppm) to xylene, which was 37.2 times higher than that of the pure NiO sensor. Moreover, the NiO/NiCr2O4 nanocomposite gas sensor showed not only superior xylene selectivity with low cross-responses to interfering gases such as ethanol (Sxylene/Sethanol = 11.8) and acetone (Sxylene/Sacetone = 10.2) but also ppb-level detection limit (1.2–50 ppb xylene) at 225 °C. The synergistic catalytic effect between NiO and NiCr2O4, optimized structural parameters and marked resistive variation due to the formation of nanoscale p-p heterojunctions were regarded as the main reasons for the ultrasensitive and selective xylene detection.

Subfields: Bioengineering, Biomedical Engineering, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/89054ebcb6281fef0dc663a43f7541fc12697d65