Improving gas sensing performance by oxygen vacancies in sub-stoichiometric WO.

Sub-stoichiometric WO has provided an alternative platform to investigate oxygen vacancies in gas sensors based on metal-oxides. We present an experimental study on the influence of sub-stoichiometric WO phase upon gas sensing performance. High-quality WO nanostructures with several values (WO, WO, WO, WO) were synthesized and used to fabricate HS gas sensors. Temperature programmed desorption of oxygen (O-TPD) shows that oxygen absorption behaviors of the as-prepared WO nanostructures are affected by oxygen vacancies, which played a critical role in the detection of HS at varying temperature range. We find that oxygen vacancies in sub-stoichiometric WO facilitate the ionosorption process and in turn enhance the performance of the gas sensor.