Porosity engineering of ZnO nanorods for efficient sensing of n-butanol vapor

Abstract

• ● A surface mesopores-abundant ZnO nanorod was successfully prepared. • ● This ZnO-based sensor showed a high response (R a /R g =193.7) towards 100 ppm n-butanol. • ● The actual detection limit was achieved as low as 0.1 ppm. • ● An ultrahigh selectivity towards n-butanol was also observed. Porosity engineering is proved as a valid strategy for promoting the gas-sensing response. In this paper, a surface mesopores-rich ZnO nanorod has been successfully demonstrated via a simple solvothermal and followed calcination approach. The microstructure, crystal phase, and surface porosity are further determined by various techniques. Owing to the abundant porosity for favorable gas-permeability and gas-solid interactions, the as-fabricated ZnO sensor displays an apparent response for detecting n-butanol vapor in terms of high response (R a /R g =193.7 – 100 ppm), low detection limit (∼0.1 ppm), as well as remarkable selectivity. Especially, these sensing results towards n-butanol are obviously better than those of reported common ZnO nanorods. This work suggests a reliable method for designing efficient gas sensor by porosity-creating method onto the metal oxide surfaces.