The enhanced alcohol-sensing response of ultrathin WO₃nanoplates

Abstract

Chemical sensors based on semiconducting metal oxide nanocrystals are of academic and practical significance in industrial processing and environment-related applications. Novel alcohol response sensors using two-dimensional WO(3) nanoplates as active elements have been investigated in this paper. Single-crystalline WO(3) nanoplates were synthesized through a topochemical approach on the basis of intercalation chemistry (Chen et al 2008 Small 4 1813). The as-obtained WO(3) nanoplate pastes were coated on the surface of an Al(2)O(3) ceramic microtube with four Pt electrodes to measure their alcohol-sensing properties. The results show that the WO(3) nanoplate sensors are highly sensitive to alcohols (e.g., methanol, ethanol, isopropanol and butanol) at moderate operating temperatures (260-360 degrees C). For butanol, the WO(3) nanoplate sensors have a sensitivity of 31 at 2 ppm and 161 at 100 ppm, operating at 300 degrees C. For other alcohols, WO(3) nanoplate sensors also show high sensitivities: 33 for methanol at 300 ppm, 70 for ethanol at 200 ppm, and 75 for isopropanol at 200 ppm. The response and recovery times of the WO(3) nanoplate sensors are less than 15 s for all the test alcohols. A good linear relationship between the sensitivity and alcohol concentrations has been observed in the range of 2-300 ppm, whereas the WO(3) nanoparticle sensors have not shown such a linear relationship. The sensitivities of the WO(3) nanoplate sensors decrease and their response times become short when the operating temperatures increase. The enhanced alcohol-sensing performance could be attributed to the ultrathin platelike morphology, the high crystallinity and the loosely assembling structure of the WO(3) nanoplates, due to the advantages of the effective adsorption and rapid diffusion of the alcohol molecules.

Two-Dimensional Materials for Sensing: Graphene and Beyond

“…Uniform CuO nanosheets synthesized by mild hydrothermal method in the presence of CTAB showed stable and similar gas sensing response to combustible gases such as ethanol, acetone and gasoline [101]. 2D WO3 nanoplate based sensors showed superhigh sensitivity to different alcohols such as methanol, ethanol, isopropanol and butanol at operating temperatures of 260-360 °C [102]. The high specific surface area arising from the ultrathin plate like structure and the high crystallinity of WO3 nanoplates led to fast and effective adsorption of alcohol molecules.…”

“…Besides graphene, research has also centered on gas sensors based on various 2D materials such as TMDs especially MoS2 [80][81][82][83][84][85][86][87], WS2 [88][89][90], MoSe2 [91] and phosphorene [92,93]. 2D nanostructures in the form of nanosheets (NSs), nanowalls, nanoplates, etc., made from ZnO, NiO, CuO, WO3, SnO2, etc., have also proven as successful sensing materials, which could be used as building blocks for the fabrication of gas sensors [94][95][96][97][98][99][100][101][102][103][104][105][106][107][108].…”

Study of the Structural, Morphological and Electrical Properties of WO₃ Nanopowders which Use as Gas Sensors

“…These devices are also capable to detecting many other compounds in vapor state such as ethanol, methanol, propanol, etc. within the atmosphere [2,3]. Thus, in order to be able to use these devices for detecting various pollutants in the atmosphere, it is necessary to understand their behavior when placed in contact with tungsten oxidebased gas sensors [4].…”

Novel pseudo-morphotactic synthesis and characterization of tungsten nitride nanoplates

“…The above tungstate-based inorganic-organic hybrid nanobelts were found to be an excellent precursor for the synthesis of WO 3 nanoplates and WO 3 nanoparticles with superhigh specific surface areas and enhanced gas-sensing properties [41][42][43][44]. The advantage of the precursor routes towards inorganic nanocrystals is the controllability in shapes and sizes of the products.…”