Analysis of Recovery Time of Pt-, Pd-, and Au-Loaded SnO2 Sensor Material with Nonanal as Large-Molecular-Weight Volatile Organic Compounds

doi:10.18494/sam.2016.1396

Cited by 2 publications

(1 citation statement)

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“…Single-crystalline nanowires are characterized by large surface-to-volume ratio, and their surfaces consist of a specific crystal plane. , The large surface-to-volume ratio of nanowires with defined crystal planes essentially allows us to perform accurate spectroscopic and mass-spectrometric measurements, even with a low density of molecules adsorbed on the solid surface. As a model system, this work focuses on the interaction between the ZnO surface and nonanal, which is one of the most promising disease markers that can be detected in breath by metal oxide sensors. − Although many successful ZnO-based aldehyde sensors have been reported, only the simple oxidation of nonanal has been considered as the sensing mechanism. , A comprehensive understanding of the interaction between aldehydes and metal oxide surfaces is clearly essential to design and improve their performances. Because the conditions of the metal oxide surface strongly affect its chemical reactivity, we carefully examined these effects for ZnO nanowire surfaces, by performing thermal pretreatments on the nanowires.…”

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confidence: 99%

Rational Method of Monitoring Molecular Transformations on Metal-Oxide Nanowire Surfaces

et al. 2019

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Metal-oxide nanowires have demonstrated excellent capability in the electrical detection of various molecules based on their material robustness in liquid and air environments. Although the surface structure of the nanowires essentially determines their interaction with adsorbed molecules, understanding the correlation between an oxide nanowire surface and an adsorbed molecule is still a major challenge. Herein, we propose a rational methodology to obtain this information for low-density molecules adsorbed on metal oxide nanowire surfaces by employing infrared p-polarized multiple-angle incidence resolution spectroscopy and temperature-programmed desorption/gas chromatography–mass spectrometry. As a model system, we studied the surface chemical transformation of an aldehyde (nonanal, a cancer biomarker in breath) on single-crystalline ZnO nanowires. We found that a slight surface reconstruction, induced by the thermal pretreatment, determines the surface chemical reactivity of nonanal. The present results show that the observed surface reaction trend can be interpreted in terms of the density of Zn ions exposed on the nanowire surface and of their corresponding spatial arrangement on the surface, which promotes the reaction between neighboring adsorbed molecules. The proposed methodology will support a better understanding of complex molecular transformations on various nanostructured metal-oxide surfaces.

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