Highly Selective Ethanol Gas Sensor of 1-D Belt Featured In₂O₃ Structures: Effects of Cr Dopant Ion

Herein, the pure and Cr-doped In<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> belt featured structures with doping level at 2 mol% was produced by the electrospinning method, followed by annealing at 700° C. A comprehensive comparison of the structural, microstructural and surface defects analysis of the produced In<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> structures was investigated to evaluate their gas sensing performance. The Cr-doped In<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> sensor presented an enhanced response of 2. 8 to 50 ppm ethanol at 100° C along with great selectivity, low detection limit of 5.12 ppm, as well as fast response/recovery time of 39 / 77 s. PL and XPS findings showed that the improved ethanol sensing behavior stems from oxygen related defects in high concentrations which are induced by Cr addition. The high concentration of such defects provides more pathways for ethanol adsorption/desorption and oxygen species formation. This study demonstrated that a Cr-doped In sensor with 2 mol% is a promising sensing layer for detecting ethanol in food safety applications.