Plasma-Assisted Growth of β-MnO2 Nanosystems as Gas Sensors for Safety and Food Industry Applications

The development of efficient sensors for security field and food quality control applications has gained an ever-increasing attention for various end-uses. In this context, this work reports on the preparation of β-MnO2 nanosystems by plasma enhanced-chemical vapor deposition (PE-CVD), using a fluorinated Mn(II) diamine-diketonate as single-source precursor for both Mn and F. Modulations of oxygen partial pressure enable to tailor not only the morphology and oxygen vacancy content, but also fluorine doping level of the resulting systems. For the first time, the gas sensing performances of PE-CVD β-MnO2 nanomaterials are tested in the detection of acetonitrile, a poisonous chemical warfare agent (CWA) simulant, and ethylene, an important marker of fruit ripening. The obtained results demonstrate that the fabricated sensors can efficiently detect these analytes, with the best responses at moderate temperatures (≤200 °C), enhanced by a higher oxygen vacancy content and fluorine concentration. These features, coupled with the good selectivity and response times, candidate the developed systems as amenable platforms for practical applications.