Enhanced acetone gas sensing properties by aurelia-like SnO2 micro-nanostructures

Abstract

In this research, well defined, three-dimensional, aurelia-like tin dioxide (SnO₂) micro-nanostructures have been successfully obtained using a simple and easy one-step, low temperature, hydrothermal strategy in the presence of cetyltrimethylammonium bromide and poly(vinylpyrrolidone). The use of these SnO₂ nanostructures was further developed for use in acetone gas detection. The unique structure and morphology of the SnO₂ nanostructures were comprehensively characterized using techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM) and high-resolution TEM. The results revealed that the aurelia-like SnO₂ micro-nanostructures were composed of two parts: the crown and tentacles. The crown and tentacles were assembled from a chassis of mass stunted, disorderly, cumulate nanosheets and a large number of curvy, uneven nanobelts, respectively. The special aurelia-like structure of the SnO₂ micro-nanostructures endows the nanostructure-based sensors with enhanced acetone gas sensing performance such as a fast response time (2 s)/recovery time (23 s), high sensitivity, good repeatability and good sensing selectivity at lower working temperatures. The possible formation growth mechanism of the aurelia-like micro-nanostructures and a morphology dependent sensing mechanism are proposed.