Temperature-dependent selectivity of bead-like TeO2 nanostructured gas sensors

摘要: Bead-like p-TeO2 nanowires (NWs) were obtained directly from Te powder by thermal evaporation along with assisting 40 sccm of O2 gas. Scanning and transmission electron microscopy showed that the two different formation origins for types bead-like TeO2 NWs take place at vicinity surface are characterized (1) presence locally higher concentration saturation O2, (2) state (terraces, ledges, kinks (TLK)) reacting adsorbed oxygen atoms. In present work, gas-sensing performances NW gas sensors fabricated using a facile low-temperature route has been investigated detection nitric dioxide (NO2), ethanol (C2H5OH), hydrogen sulfide (H2S) gases contained in human breath. Specifically, this work systematically investigates response dependence temperature range 200 °C to 400 °C. The sensing capabilities respect C2H5OH, NO2, H2S without any artificial handling, such as modification, n- and/or p-type doping, heterostructure formation. selectivity adjusting operating is dependent on target gas, which attributed an interaction between molecules specific temperature. particular, show quite superior sensitivity 250, 350, °C, respectively. Thus, promising detections high ppm level may contribute realization more selective sensors.