Study of modified tin oxide based structures as gas sensors.

• Grant number: 13/08734-3
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): July 01, 2013
• Effective date (End): February 28, 2015
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Marcelo Ornaghi Orlandi
• Grantee: Martin Schwellberger Barbosa
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

In this research project we suggest a study intending to understand the gas-solid interactions mechanisms that occur on the surface of both pure and modified (platinum and palladium) tin oxide (II) based nanostructures. The chosen structures are microdisks and nanobelts made of SnO, that although thermodynamically instable, former studies performed at our research group have shown that they are very sensitive and selective for the detection of oxidizing gases. Therefore, we expect that the surface's modifications make them even more selective and sensitive, which is very desirable for practical applications. The materials will be synthesized by the carbothermic reduction method and then characterized by X-ray diffraction, specific surface area measurement, high resolution scanning and transmission electron microscopy and X-ray absorption near edge spectroscopy techniques. The materials will also be characterized regarding their gas sensors proprieties, in the presence of oxidizing and reducing gases (for instance, NO2 CO and H2S) in very low concentrations (ppm level) and working temperatures between 100ÚC and 350 ÚC. One of the biggest challenges of the work will be the in situ study of the oxidation state of the sensor at different temperatures by X-ray absorption near edge spectroscopy that will be made alongside with the electrical measurements, in similar conditions of the sensor operation. The main contribution to the literature will be the study of solid-gas interactions in thermodynamically unstable materials (SnO) superficially modified. We hope that in the working conditions, the developed materials will allow the development of high sensitivity and sensibility gas-sensors, which are very important for future practical applications for this material.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BARBOSA, MARTIN S.; SUMAN, PEDRO H.; KIM, JAE J.; TULLER, HARRY L.; VARELA, JOSE A.; ORLANDI, MARCELO O.. Gas sensor properties of Ag- and Pd-decorated SnO micro-disks to NO2, H-2 and CO: Catalyst enhanced sensor response and selectivity. SENSORS AND ACTUATORS B-CHEMICAL, v. 239, p. 253-261, FEB 2017. (13/18511-1, 12/51195-3, 13/08734-3, 14/50725-4)

BARBOSA, MARTIN S.; SUMAN, PEDRO H.; KIM, JAE J.; TULLER, HARRY L.; ORLANDI, MARCELO O.. Investigation of electronic and chemical sensitization effects promoted by Pt and Pd nanoparticles on single-crystalline SnO nanobelt-based gas sensors. SENSORS AND ACTUATORS B-CHEMICAL, v. 301, DEC 12 2019. (13/18511-1, 12/51195-3, 13/08734-3, 14/50725-4)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

BARBOSA, Martin Schwellberger. Caracterização de estruturas de óxido de estanho modificado como sensores de gases. 2015. Master's Dissertation - Universidade Estadual Paulista (Unesp). Instituto de Química. Araraquara Araraquara.