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Rachel Day, Courtney Severino, Riley Yager, and Dr. Andrei Stanishevsky, Department of Physics, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL 35294-1170, USA
Tungsten oxide (WO3) nanofibers (NFs) demonstrate strong potential for numerous applications in catalysis and gas sensing, and the demand for this material is growing fast. WO3 NFs are fabricated mainly by using the direct current electrospinning (DCES) methods followed by thermal processing of as-spun precursor fibers. Traditional capillary nozzle DCES usually produces, in terms of the final product, only 30–100 mg/h of WO3 NFs with fiber diameters of 50–800 nm with different surface morphologies, depending on the thermal processing temperature. In the present work, WO3 NFs have been produced at up to 6.0 g/h rates by using a high-throughput, free-surface alternating force electrospinning (AFES) technique. Precursor nanofiber sheets with up to 1200 cm2 area and 2–3 mm thickness were prepared and annealed at 450–600 oC to remove the polymer carrier and crystallize the tungsten oxide NFs. The effects of the precursor composition (in particular, silica addition) and thermal treatment protocol on the shrinkage and mechanical integrity of nanofibrous sheets were studied. Microstructure and textural properties of pure and silica-doped WO3 NFs were analyzed using XRD, FTIR and Raman spectroscopies, and SEM/EDS. The results were compared with the available data for DCES WO3 NFs. AFES produced WO3 NFs with 100–300 nm diameters and 20–40 nm WO3 crystallite size have been tested as the components of nanofibrous gas sensor and catalytic membrane structures. Specifically, the temperature dependent sensitivity and response time of AFES pure and silica-doped WO3 nanofibrous structures to ethanol, H2, CO, and CO2 were determined. AFES WO3 NFs have shown promising results as a visible light catalyst for CO2 reduction.
Presenter: Rachel Day
Institution: University of Alabama at Birmingham
Type: Poster
Subject: Physics/Astronomy
Status: Approved
