Fabrication and Characterization of Directly Synthesized WSe₂Nano-flowers for NO2 Sensing

In this article, we report fabrication and characterization of tungsten diselenide (WSe2) nano-flowers for Nitrogen Dioxide (NO2) gas sensing. In this process, Tungsten diselenide (WSe2) nano-flowers were directly synthesized using solvothermal route on FTO coated glass substrate. The nano-flower structure of the directly synthesized film is depicted in FESEM image. The synthesized sample was characterized for its crystallinity and phase purity through X-ray Diffraction (XRD). Energy Dispersive X-ray (EDX) determined its elemental composition, and Field Emission-Scanning Electron Microscopy (FE-SEM) clearly confirmed its nanostructure and surface morphology. These directly synthesized WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> nano-flower structures are responsible for enhanced NO2 gas sensing. The fabricated device has shown 45.12% sensing response with 2 ppm gas exposure at -1 V bias (at 120°C). The selectivity of the fabricated device has also been analyzed with ammonia, acetone, methanol and ethanol.