Sensing performance for ethylene glycol of hydrothermally self-assembled 3D WO3

A series of hierarchically self-assembled three-dimensional (3D) WO3 with different mass ratios of urea to sodium tungstate were prepared by a one-step hydrothermal method, and the sensing characteristics for ethylene glycol were studied. The results showed that when the mass ratio of urea to sodium tungstate is 0.1:1, the sample WO30.1 exhibited the highest response (740.3) to 100 ppm ethylene glycol at 200 degrees C. In addition, sample WO3-0.1 had excellent selectivity, repeatability, stability and moisture resistance. Due to the hierarchically self-assembled 3D structure, sample WO3-0.1 possessed the maximum number of mesopores, the vacant oxygen concentration of sample WO3-0.1 was twice as much as the sample WO3-0 without urea. Moreover, the growth mechanism of hierarchically self-assembled 3D WO3 was explored by discussing the synergistic effect of ammonium chloride and oxalic acid. Based on outstanding properties for ethylene glycol, the 3D WO3 prepared in this work will have practical significance and potential applications for environmental monitoring.