Cu/CuO@ZnO Hollow Nanofiber Gas Sensor: Effect of Hollow Nanofiber Structure and P-N Junction on Operating Temperature and Sensitivity.

Sung-Ho Hwang,Young Kwang Kim,Seong Hui Hong,Sang Kyoo Lim

doi:10.3390/s19143151

Sung-Ho Hwang, Young Kwang Kim + Show 2 more

Open Access

https://doi.org/10.3390/s19143151

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Abstract

For the fast and easy detection of carbon monoxide (CO) gas, it was necessary to develop a CO gas sensor to operate in low temperatures. Herein, a novel Cu/CuO-decorated ZnO hollow nanofiber was prepared with the electrospinning, calcination, and photodeposition methods. In the presence of 100 ppm CO gas, the Cu/CuO-photodeposited ZnO hollow nanofiber (Cu/CuO@ZnO HNF) showed twice higher sensitivity than that of pure ZnO nanofiber at a relatively low working temperature of 300 °C. The hollow structure and p–n junction between Cu/CuO and ZnO would be considered to contribute to the enhancement of sensitivity to CO gas at 300 °C due to the improved specific surface area and efficient electron transfer.

Highlights

Carbon monoxide (CO), a dangerous byproduct of the incomplete combustion of fossil fuels, adversely affects human health because its high reactivity with blood erythrocytes results in oxygen deficiency in the body [1,2]
We focused on developing a CO gas sensor with good sensitivity, and ZnO was selected as the base material among the metal oxides because of its n-type nature and good thermal stability [12]
To design a CO gas sensor with a new structure, the ZnO hollow nanofiber was prepared with the electrospinning and calcination method, as previously reported [23,24]

Summary

Introduction

Carbon monoxide (CO), a dangerous byproduct of the incomplete combustion of fossil fuels, adversely affects human health because its high reactivity with blood erythrocytes results in oxygen deficiency in the body [1,2]. We focused on developing a CO gas sensor with good sensitivity, and ZnO was selected as the base material among the metal oxides because of its n-type nature and good thermal stability [12]. Another important issue is lowering the operating temperature of the sensor to improve durability and reduce the danger on account of high operating temperatures (~400 ◦ C) [13,14]. Spike-shaped CuO/ZnO nanorods were developed for lowering the operating temperature of detecting 100 ppm of CO gas [15]

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Conclusion