Highly sensitive plate-like Bi2WO6 prepared by simple hydrothermal method

Abstract

In this study, nanosheet-like Bi2WO6 is successfully prepared with a simple hydrothermal method and annealing step. The crystal structure, morphology, and element distribution of Bi2WO6 are analyzed by XRD, EDX, SEM, TEM, ESR and O2-TPD characterization methods. The results show that the prepare bismuth tungstate has no impurity elements, and the distribution of bismuth, tungsten, and oxygen are very uniform. After a detailed analysis of the sample, we also conduct XPS testing. This test is to further understand the surface composition and chemical state of the sample. The results of the XPS test are very clear, revealing that the vacancy oxygen (Ov) content in the sample is as high as 51.85 %. This also explains why bismuth tungstate has a smooth surface but has a high response to triethylamine. After gas sensing performance testing, it is found that Bi2WO6 has good selectivity and long-term stability towards the toxic and harmful triethylamine. At 220 °C, the detection response value for 100 ppm triethylamine gas is 25.5, with a sensor response time of 15 s and a recovery time of 17 s.