V2O5 gas sensors: A review

Vanadium pentoxide has attracted the researchers' interest for its potential gas sensing applications. Its unique electrical and optical properties make it very interesting for the development of chemiresistive, gasochromic and cataluminescence gas sensors. Throughout the years, various processing techniques have been developed for the synthesis of gas sensing vanadium pentoxide nanostructures or thin films such as physical vapor deposition, spray-pyrolysis, polycondensation, precipitation, melt-quenching, sol-gel, elec-trospinning, solvothermal growth, and thermal oxidation. The performance of the fabricated devices to-wards a target gas depends on the sensing layer's morphology, the operating temperature and the sensing mechanism: gas adsorption, electron hopping, or chemical interaction. This state of art of vanadium pentoxide gas sensors covers all aspects of their fabrication, sensing mechanism and transducing principles. The sensitivity, selectivity, stability, response and recovery times of these sensors are evaluated. Their compliance with the limit of detection required by some target applications is also discussed. The ad-vantages of vanadium pentoxide for gas sensing applications is highlighted. At the end, the article concludes with an outlook of the challenges and opportunities facing vanadium pentoxide gas sensors. (c) 2021 Elsevier B.V. All rights reserved.