Structural and electronic engineering of 3DOM WO by alkali metal doping for improved NO sensing performance

• Published in: Nanoscale 2016-05, Vol.8 (2), p.1622-1631
• Main Authors: Wang, Zhihua, Fan, Xiaoxiao, Han, Dongmei, Gu, Fubo
• Format: Article
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c6nr00858e

Novel alkali metal doped 3DOM WO 3 materials were prepared using a simple colloidal crystal template method. Raman, XRD, SEM, TEM, XPS, PL, Hall and UV-Vis techniques were used to characterize the structural and electronic properties of all the products, while the corresponding sensing performances targeting ppb level NO 2 were determined at different working temperatures. For the overall goal of structural and electronic engineering, the co-effect of structural and electronic properties on the improved NO 2 sensing performance of alkali metal doped 3DOM WO 3 was studied. The test results showed that the gas sensing properties of 3DOM WO 3 /Li improved the most, with the fast response-recovery time and excellent selectivity. More importantly, the response of 3DOM WO 3 /Li to 500 ppb NO 2 was up to 55 at room temperature (25 °C). The especially high response to ppb level NO 2 at room temperature (25 °C) in this work has a very important practical significance. The best sensing performance of 3DOM WO 3 /Li could be ascribed to the most structure defects and the highest carrier mobility. And the possible gas sensing mechanism based on the model of the depletion layer was proposed to demonstrate that both structural and electronic properties are responsible for the NO 2 sensing behavior. Based on structural and electronic engineering, alkali metal doped 3DOM WO 3 materials with high sensitivity towards ppb level NO 2 were synthesized.