Hydrothermal synthesis of hierarchical SnO2 nanostructures made of superfine nanorods for smart gas sensor

• Published in: Applied surface science 2016-02, Vol.364, p.371-377
• Main Authors: Kuang, Xinliang, Liu, Tianmo, Shi, Dongfeng, Wang, Wenxia, Yang, Mingping, Hussain, Shahid, Peng, Xianghe, Pan, Fusheng
• Format: Article
• Language: English
• Subjects: Density; Ethanol; Gas sensor; Gas sensors; Hydrothermal method; Nanorods; Nanostructure; Nucleation; SnO2; Synthesis; Tin dioxide; Tin oxides
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2015.12.172

•Hierarchical SnO2 nanostructures made of superfine nanorods were controlled hydrothermal synthesized.•The diameter and density of the nanorods can be tailored by adding NaOH.•The as-prepared SnO2 nanostructures were found showing enhanced gas sensing activity to ethanol. We report synthesis of hierarchical SnO2 nanostructures by a facile hydrothermal method. Extensive structural characterizations demonstrate that the well-defined hierarchical nanostructures are composed of numerous one-dimensional nanorods, the diameter and density of which can be precisely tailored by adjusting the dosage of NaOH. Interestingly, with more NaOH added, smaller and denser nanorods are formed, which is consistent with the assumption. We proposed that the nucleation process was facilitated in such case leading to all-direction rapider growth. Moreover, the nucleation process could be started by the decomposition of preformed ZnSn(OH)6 induced by alkali etching. Based on the comparative experiments, a possible growth mechanism for hierarchical SnO2 nanostructures has been proposed and discussed in detail. The gas sensing properties of the as-prepared hierarchical SnO2 nanostructures were all tested. It was found that the S3 sample which assembled with smallest and densest nanorods showed the excellent sensitivities toward ethanol.