Electrospun copper oxide nanofibers for H2S dosimetry

• Published in: Physica status solidi. A, Applications and materials science Vol. 209; no. 5; pp. 911 - 916
• Main Authors: Hennemann, Jörg, Sauerwald, Tilman, Kohl, Claus-Dieter, Wagner, Thorsten, Bognitzki, Michael, Greiner, Andreas
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.05.2012; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: copper oxide; gas sensor; hydrogen sulfide; nanofibers
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201100588

We present the preparation and characterization of a novel copper(II)oxide (CuO) nanofiber based sensor with very high sensitivity and selectivity to hydrogen sulfide (H2S). The working principle is based on the phase transition of semiconducting p‐type CuO to strongly degenerated p‐type copper sulfide (CuS) with metallic conductivity. Electrospun polymer fiber networks of polyvinyl butyrate (PVB) and Cu(NO3)2 were attached on standard gas sensing substrates and calcined to CuO at 600 °C in ambient air for 24 h. Continuous exposure to H2S (0.1–5 ppm) as well as a sequence of 1 ppm H2S pulses result in a dosimeter type behavior of the nanofiber sensors. Triggered by a certain dose (gas concentration multiplied by time) a steep conductance increase of the sensitive layer over several orders of magnitude is observed. After reaching this percolation threshold only small conductance changes were observed. These fiber based sensors show a remarkably high specificity, there is no response to carbon monoxide, hydrogen, and methane at 160 °C. The fiber network can be regenerated by raising the operating temperature to 350 °C for 30 min in absence of H2S. Conductance change under exposure to various gases. Continuous recording with one measurement per second.