Self-Assembled 3D ZnO Porous Structures with Exposed Reactive {0001} Facets and Their Enhanced Gas Sensitivity

Sensors

Jin Chang¹  Muhammad Z. Ahmad²  Wojtek Wlodarski² 

[1] School of Chemistry, Physics & Mechanical Engineering, QUT, Brisbane, QLD 4000, Australia; E-Mail:;School of Electrical & Computer Engineering, RMIT University, Melbourne, VIC 3000, Australia; E-Mails:

关键词: zinc oxide;    gas sensors;    self-assembly;    porous structure;   

DOI  :  10.3390/s130708445

来源: mdpi

【 摘 要 】

Complex three-dimensional structures comprised of porous ZnO plates were synthesized in a controlled fashion by hydrothermal methods. Through subtle changes to reaction conditions, the ZnO structures could be self-assembled from 20 nm thick nanosheets into grass-like and flower-like structures which led to the exposure of high proportions of ZnO {0001} crystal facets for both these materials. The measured surface area of the flower-like and the grass, or platelet-like ZnO samples were 72.8 and 52.4 m²·g⁻¹, respectively. Gas sensing results demonstrated that the porous, flower-like ZnO structures exhibited enhanced sensing performance towards NO₂ gas compared with either grass-like ZnO or commercially sourced ZnO nanoparticle samples. The porous, flower-like ZnO structures provided a high surface area which enhanced the ZnO gas sensor response. X-ray photoelectron spectroscopy characterization revealed that flower-like ZnO samples possessed a higher percentage of oxygen vacancies than the other ZnO sample-types, which also contributed to their excellent gas sensing performance.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.