Study on comparing WO3 and W18O49 gas sensing abilities under NO2 environment

In this study, tungsten films with 150 and 300 nm thick were made by DC magnetron sputtering. The annealing treatment at 700 A degrees C environment was used to characterize the influence of annealing duration (30, 45, 60, 75 and 90 min) on the morphology, phase and microstructure. Finally, we compared one-dimension W18O49 nanowires with one-dimension WO3 nanowires on NO2 gas sensing ability. In this research, W18O49 and WO3 were made as 150 nm thick films by annealing for 60 and 90 min at 700 A degrees C environment, respectively. One-dimension W18O49 and WO3 nanowires were examined by X-ray diffraction (XRD). For the XRD result, the W18O49 with strongest diffraction peaks appears at 2 theta = 23.454A degrees, phase with (010) growth plan; while WO3 with strongest diffraction peaks appears at 2 theta = 23.120A degrees, 23.586A degrees, 24.380A degrees, phase with (002), (020), (200) growth plane. This study focused on the different NO2 concentrations (10, 20, 50 and 100 ppm) at a working temperature of 150 A degrees C. W18O49 and WO3 gas sensing performance were dependent on NO2 concentrations. W18O49 sensing ability on different NO2 concentrations (10, 20, 50 and 100 ppm) was 1.436, 1.671, 1.816 and 1.973, respectively. WO3 sensing ability on different NO2 concentrations (10, 20, 50 and 100 ppm) was 1.462, 1.726, 1.970 and 2.365, respectively.