Optical Sensing of Molecular Oxygen (O2) via Metal Oxide Photoluminescence: A Comparative Study of TiO2, SnO2 and ZnO

Chemosensors

卷:9

Sara Morandi¹  Pasqualino Maddalena²  Stefano Lettieri³  Laura Giordano⁴  Ambra Fioravanti⁵  Maria Cristina Carotta⁵  Pietro Marani⁵ 

[1] Department of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy;

[2] Department of Physics, Università degli Studi di Napoli “Federico II”, Via Cupa Cintia 21, 80126 Naples, Italy;

[3] Institute for Applied Sciences and Intelligent Systems “E. Caianiello”, National Research Council (ISASI-CNR), Via Cupa Cintia 21, 80126 Naples, Italy;

[4] Institute of Marine Sciences, National Research Council (ISMAR-CNR), Calata Porta di Massa, 80133 Naples, Italy;

[5] Institute of Sciences and Technologies for Sustainable Energy and Mobility, National Research Council (STEMS-CNR), Via Canal Bianco 28, 44124 Ferrara, Italy;

关键词: titanium dioxide;    zinc oxide;    tin dioxide;    photoluminescence;    optical sensors;    oxygen sensors;   

DOI  :  10.3390/chemosensors9070163

来源: DOAJ

【 摘 要 】

A comparative study is presented on the photoluminescence (PL) response toward molecular oxygen (O₂) in tin dioxide (SnO₂), zinc oxide (ZnO) and titanium dioxide (TiO₂) nanoparticles. The findings show that both PL enhancement and PL quenching can be observed on different materials, arguably depending on the spatial localization of the defects responsible for the PL emission in each different oxide. No significant results are evidenced for SnO₂ nanoparticles. ZnO with red/orange emission shown an O₂-induced PL enhancement, suggesting that the radiative emission involves holes trapped in surface vacancy oxygen centers. While the ZnO results are scientifically interesting, its performances are inferior to the ones shown by TiO₂, which exhibits the most interesting response in terms of sensitivity and versatility of the response. In particular, O₂ concentrations in the range of few percent and in the range of a few tenths of a part per million are both detectable through the same mixed-phase TiO₂ sample, whose rutile phase gives a reversible and fast response to larger (0.4–2%) O₂ concentration while its anatase phase is usable for detection in the 25–75 ppm range. The data for rutile TiO₂ suggest that its surfaces host deeply trapped electrons at large densities, allowing good sensitivities and, more notably, a relatively unsaturated response at large concentrations. Future work is expected to improve the understanding and modeling of the photophysical framework that lies behind the observations.

【 授权许可】

Unknown