H2S gas sensing properties of CuO-functionalized WO3 nanowires

This paper compares the H2S gas sensing properties of CuO-functionalized WO3 nanowires with those of CuO-functionalized SnO2 nanorods to see the relative contributions of the nanowire material (WO3 or SnO2) and functionalization material (CuO) to H2S gas sensing properties. Multiple networked CuO-functionalized WO3 nanowire sensors showed electrical responses to H2S gas at 300 °C comparable to their CuO-functionalized SnO2 nanorod counterparts. The CuO-functionalized WO3 nanowires and CuO-functionalized SnO2 nanorods exhibited responses of ~673% and ~798%, respectively, to 100 ppm H2S at 300 °C. The ratio of the response of CuO-functionalized WO3 nanowires to H2S gas to that of pristine WO3 nanowires was 3.65, whereas the ratio of the response of CuO-functionalized SnO2 nanorods to H2S gas to that of pristine SnO2 nanorods was 3.84. Differences in sensing mechanism between CuO-functionalized WO3 nanowires and CuO-functionalized SnO2 nanorods are also discussed.