Issue 58, 2016, Issue in Progress

New insights into the sensing mechanism of shape controlled ZnO particles

Abstract

The sensing behavior of pyramidal (PY), prismatic hexagonal (EP) and hexagonal rod-like (ER) ZnO micro and sub-microparticles, has been compared with that of commercial ZnO (ZnO®) particles having nanometric size and uneven shape. The performances have been firstly related to the predominance of specific crystal surfaces and then, more in depth, to the paramagnetic defects in ZnO (Image ID:c6ra09824j-t1.gif and Image ID:c6ra09824j-t2.gif), detected by Electron Spin Resonance (ESR), in order to associate the particles morphology with the defects amount and reactivity and, in turn, with a particular sensing mechanism. The results showed that the sensing behavior of ZnO® containing irregular nanoparticles is essentially related to the alternate formation and filling of oxygen vacancies during the gas pulse (oxygen vacancy mechanism), while that of ER and EP crystals does not seem to directly involve the Image ID:c6ra09824j-t3.gif defects. In particular, the sensing properties of shape controlled ZnO particles are mainly attributed to the ability of (0001) exposed surfaces in favoring a far better chemisorption of negatively charged oxygen species, then available for the reactions with the reducing gas (i.e. ionosorption mechanism). The outcomes and the approach adopted in this study may positively contribute to the debate still existing between the oxygen vacancy and ionosorption models by giving indications on the predominance of a specific sensing mechanism in shape controlled ZnO.

Graphical abstract: New insights into the sensing mechanism of shape controlled ZnO particles

Supplementary files

Article information

Article type
Paper
Submitted
15 Apr 2016
Accepted
24 May 2016
First published
25 May 2016

RSC Adv., 2016,6, 52987-52997

New insights into the sensing mechanism of shape controlled ZnO particles

M. D'Arienzo, M. Redaelli, B. Di Credico, S. Polizzi, R. Scotti and F. Morazzoni, RSC Adv., 2016, 6, 52987 DOI: 10.1039/C6RA09824J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements