Preparation and Gas Sensing Performance of Hierarchical Porous ZnO-based Materials with Sunflower Rods as a Biological Template

• Published in: Chemical research in Chinese universities Vol. 35; no. 5; pp. 755 - 761
• Main Authors: Wang, Bowei, Zeng, Qingrui, Chen, Shu, Yue, Tongtong, Han, Bing, Feng, Wei, Yang, Defeng
• Format: Journal Article
• Language: English
• Published: Changchun Jilin University and The Editorial Department of Chemical Research in Chinese Universities 01.10.2019; Springer Nature B.V
• Subjects: Analytical Chemistry; Butanol; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Electron microscopy; Gas sensors; Heterojunctions; Inorganic Chemistry; Microscopy; Organic Chemistry; Photoelectrons; Physical Chemistry; Porous materials; Recovery time; Response time; Rods; Selectivity; Structural hierarchy; Sunflowers; Tin dioxide; Wurtzite; X ray photoelectron spectroscopy; Zinc oxide; Gas sensitivity; Butanol; ZnO; Sunflower stem; Graded porous structure; SnO
• ISSN: 1005-9040; 2210-3171
• DOI: 10.1007/s40242-019-9125-2

A graded porous structure SnO 2 /ZnO composite was prepared with sunflower rods as a biological template. The prepared samples were subjected to phase analysis by scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffractiometry(XRD) and X-ray photoelectron spectroscopy(XPS). ZnO sample was a pure phase of hexagonal wurtzite, and the template had been completely removed. The surface of the sample presented a honeycomb-like structure of a sunflower rod template, which was formed by interconnecting the porous channels, and had a smaller average size and exhibited n-n heterojunction at the n-type ZnO interface. Compared with that of pure ZnO, the response of the hierarchical porous structure SnO 2 /ZnO composite to 100 mg/L n -butanol reached a maximum of 40.61 at 240 °C, about 2.7 times higher than that of pure ZnO. Its response time and recovery time are 6 and 3 s, respectively, which are also better than those of pure ZnO. SnO 2 /ZnO composite exhibits good gas selectivity, which is related to the improvement of the structure and the forming of n-n heterojunctions of the material.