Nanorods-assembled ZnO microflower as a powerful channel for n-butanol sensing

Abstract

Assembly of one-dimensional (1D) nanorods into organized three-dimensional (3D) architectures, coupled with open interspaces, is favorable for gas-interface interaction and diffusion. In this paper, a single-crystalline nanorods-built ZnO microflower has been successfully prepared through a facile hydrothermal route. The surface morphology, crystal structure, element composition and pore characteristic of this ZnO product were also conducted using diverse technical methods. In addition, the morphology evolution process was further clarified through a time-dependent reaction. The ZnO microflower-based gas sensor declared a remarkable response towards n-butanol in terms of outstanding selectivity, low detection limit (~ 0.1 ppm), and rapid response rate (≤ 12 s for 1–100 ppm n-butanol). Moreover, this ZnO sensor still maintained a powerful response (Ra/Rg = 46.53) towards 100 ppm n-butanol when exposed to high-level relative humidity (RH = 80%). The improvement of gas-sensing response was discussed in detail. This work demonstrates that integration of 1D nanorods into rational 3D structure is an efficient strategy for fabricating high-performance gas sensor.