Yuhong Zhang,Yanchang Liu,Junlong Liu,Zhihao Qu,Siye Tian,Hang Liu
Here, Ce-doped ZnO flower-like nanosheets are prepared by one-step hydrothermal method . The sensor based on Ce–ZnO composite exhibits excellent gas-sensing properties to acetone. Compared with pure ZnO, the response of Ce–ZnO composite is increased by 5.5 times, and the optimum operating temperature is reduced by 60 °C. The gas-sensing properties of the sensor to acetone under different humidity conditions are investigated. The redox reaction of Ce element increases the anti-humidity of Ce–ZnO sensor. Finally, the gas sensing mechanism of Ce–ZnO nanomaterial and anti-humidity principle are discussed in detail. The result can provide a new material for develop high sensitivity acetone sensor and a new anti-humidity strategy for designing gas sensing materials.
The development of functionalized metal oxide/reduced graphene oxide (rGO) hybrid nanocomposites concerning power equipment failure diagnosis is one of the most recent topics. In this work, WO3nanolamellae/reduced graphene oxide (rGO) nanocomposites with different contents of GO (0.5 wt %, 1 wt %, 2 wt %, 4 wt %) were synthesized via controlled hydrothermal method. X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analyses-derivative thermogravimetric analysis-differential scanning calorimetry (TG-DTG-DSC), BET, and photoluminescence (PL) spectroscopy were utilized to investigate morphological characterizations of prepared gas sensing materials and indicated that high quality WO3nanolamellae were widely distributed among graphene sheets. Experimental ceramic planar gas sensors composing of interdigitated alumina substrates, Au electrodes, and RuO2heating layer were coated with WO3nanolamellae/reduced graphene oxide (rGO) films by spin-coating technique and then tested for gas sensing towards multi-concentrations of acetylene (C2H2) gases in a carrier gas with operating temperature ranging from 50 °C to 400 °C. Among four contents of prepared samples, sensing materials with 1 wt % GO nanocomposite exhibited the best C2H2sensing performance with lower optimal working temperature (150 °C), higher sensor response (15.0 toward 50 ppm), faster response-recovery time (52 s and 27 s), lower detection limitation (1.3 ppm), long-term stability, and excellent repeatability. The gas sensing mechanism for enhanced sensing performance of nanocomposite is possibly attributed to the formation of p-n heterojunction and the active interaction between WO3nanolamellae and rGO sheets. Besides, the introduction of rGO nanosheets leads to the impurity of synthesized materials, which creates more defects and promotes larger specific area for gas adsorption, outstanding conductivity, and faster carrier transport. The superior gas sensing properties of WO3/rGO based gas sensor may contribute to the development of a high-performance ppm-level gas sensor for the online monitoring of dissolved C2H2gas in large-scale transformer oil.Keywords:WO3nanolamellae;reduced graphene oxide;acetylene sensing performance;gas sensing mechanism;dissolved gases in transformer oil
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