Hydrothermal Synthesis of Hierarchical SnO2 Nanostructures for Improved Formaldehyde Gas Sensing.

Pengyu Ren,Kairui You,Qingwei Shi,Lingling Qi

doi:10.3390/nano12020228

Pengyu Ren, Kairui You + Show 2 more

Open Access

https://doi.org/10.3390/nano12020228

Copy DOI

Abstract

The indoor environment of buildings affects people’s daily life. Indoor harmful gases include volatile organic gas and greenhouse gas. Therefore, the detection of harmful gas by gas sensors is a key method for developing green buildings. The reasonable design of SnO2-sensing materials with excellent structures is an ideal choice for gas sensors. In this study, three types of hierarchical SnO2 microspheres assembled with one-dimensional nanorods, including urchin-like microspheres (SN-1), flower-like microspheres (SN-2), and hydrangea-like microspheres (SN-3), are prepared by a simple hydrothermal method and further applied as gas-sensing materials for an indoor formaldehyde (HCHO) gas-sensing test. The SN-1 sample-based gas sensor demonstrates improved HCHO gas-sensing performance, especially demonstrating greater sensor responses and faster response/recovery speeds than SN-2- and SN-3-based gas sensors. The improved HCHO gas-sensing properties could be mainly attributed to the structural difference of smaller nanorods. These results further indicate the uniqueness of the structure of the SN-1 sample and its suitability as HCHO- sensing material.

Highlights

The results indicate that the SN-1 sample-based gas sensor displayed the highest response value (53.6) and fastest response and recovery speed (5/9 s) at 275 ◦ C towards 50 ppm formaldehyde
Three-dimensional hierarchical sphere-like SnO2 nanostructures with different basic units have been successfully prepared via a simple hydrothermal method
Different basic units have been successfully prepared via a simple hydrothermal method

Summary

Introduction

Indoor environments are very important to people’s livelihoods. Monitoring indoor ambient gas is a key method for developing green buildings. Monitoring HCHO in a specific environment is pressing for people’s safety and health [7,8]. Chemical gas sensors based on semiconducting oxide materials play an important role in monitoring toxic volatile organic compounds’ vapor because of low cost and good gas-sensing properties [9,10]. Microstructures and the surface area of semiconducting oxides closely affect their actual gas-sensing properties [11,12]. These vital factors could be tailored via rationally designed architectures [13]. Pan et al synthesized metal-organic framework-derived porous SnO2 nanosheets and explained its excellent formaldehyde gas-sensing abilities [15]

Methods

Results

Conclusion