NiO nanoparticle-decorated SnO2 nanosheets for ethanol sensing with enhanced moisture resistance

Gaoqiang Niu,Xiaohui Leng,Zhitao Yang,Changhui Zhao,Fei Wang,Huimin Gong

doi:10.1038/s41378-019-0060-7

Gaoqiang Niu, Xiaohui Leng + Show 4 more

Open Access

https://doi.org/10.1038/s41378-019-0060-7

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Abstract

In a high relative humidity (RH) environment, it is challenging for ethanol sensors to maintain a high response and excellent selectivity. Herein, tetragonal rutile SnO2 nanosheets decorated with NiO nanoparticles were synthesized by a two-step hydrothermal process. The NiO-decorated SnO2 nanosheet-based sensors displayed a significantly improved sensitivity and excellent selectivity to ethanol gas. For example, the 3 mol% NiO-decorated SnO2 (SnO2-3Ni) sensor reached its highest response (153 at 100 ppm) at an operating temperature of 260 °C. Moreover, the SnO2-3Ni sensor had substantially improved moisture resistance. The excellent properties of the sensors can be attributed to the uniform dispersion of the NiO nanoparticles on the surface of the SnO2 nanosheets and the formation of NiO-SnO2 p–n heterojunctions. Considering the long-term stability and reproducibility of these sensors, our study suggests that the NiO nanoparticle-decorated SnO2 nanosheets are a promising material for highly efficient detection of ethanol.

Highlights

Metal oxide semiconductors (MOX) have attracted substantial attention in the field of gas detection over the past few decades due to their ease of use and reproducible response to various gases[1,2,3]
The oxidation of the Sn(OH)[2] precipitates occurred at conditions with a high pressure and high temperature of 180 °C
In summary, tetragonal rutile SnO2 nanosheets decorated with NiO nanoparticles were successfully prepared by a template-free two-step hydrothermal method

Summary

Introduction

Metal oxide semiconductors (MOX) have attracted substantial attention in the field of gas detection over the past few decades due to their ease of use and reproducible response to various gases[1,2,3]. To further improve the sensor performance, diverse SnO2-based nanostructures, such as nanoparticles[5], nanosheets[6], nanowires[7], nanotubes[8], hollow spheres[9], and some hierarchical architectures[10,11,12], have been developed. In these reports, two-dimensional (2D) SnO2 nanostructures exhibit a rather high catalytic activity on certain surface sites, which promotes their sensing performance[1]. A p-type NiO enables an increase in the oxygen adsorption that can react with target gases[21]

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