288681 Metal Oxide Nanowire Sensors and Sensor Arrays for Hazardous Gas Detection

Thursday, November 1, 2012: 9:06 AM
408 (Convention Center )
Zhiyong Gu, Chemical Engineering, University of Massachusetts Lowell, Lowell, MA

Nanowires have been widely used for sensor applications due to their unique 1-D structure, high aspect ratio, improved specific surface area and enhanced sensitivity toward certain analytes. In this presentation, I will show our recent effort in developing various metal oxide nanowires as sensors or sensor arrays for hazardous gas detection. A variety of metal oxide nanowires, including tin oxide, copper oxide, doped tin oxides, and mixed tin-copper oxides, have been successfully synthesized by electrodeposition or codeposition method using nanoporous templates. The structure and morphology of these metal oxide nanowires were characterized by SEM, TEM, EDS, and XRD. A novel method has been developed to align the nanowires and integrate them into sensor devices or sensor arrays, using combined dielectrophoretic assembly and thermal oxidation methods. Hazardous gases, including hydrogen sulfide (H2S) and organic vapors, were tested with these nanowire sensor devices at different concentration levels and elevated temperatures. Copper oxide nanowire sensor has shown promise for H2S detection with very high sensitivity. For tin oxide based sensors, four types of doped tin oxide nanowire sensors (Pt, In, Ni, and Cu) were consolidated into an array in order to resolve the issue of poor selectivity toward organic vapor detection. Both dynamic and static methods were utilized to obtain the response kinetics and sensitivity data for analysis. Sensing performance was characterized for different organic vapors at a wide range of concentration levels. Finally, principle component analysis (PCA) and pattern recognition technique such as decision tree learning were applied to analyze the classification ability of the sensor array.

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