Humidity sensor based on mesoporous Al-doped NiO ultralong nanowires with enhanced ethanol sensing performance

Abstract

Mesoporous Al-doped NiO ultralong nanowires with better uniformity, dispersity and well-defined morphologies were synthesized by a simple surfactant based hydrothermal treatment of aqueous solution of Al(NO3)3, NiCl2 and NaC2O4 in the presence of ethylene glycol and polyethylene glycol through continuous open air heating at 500 °C. The sensing performances of the gas sensor’s based on bare and Al-doped NiO nanowires had been investigated towards ethanol, methanol, acetone, xylene, toluene and benzene. The results specified that the 3.2 at% Al-doped NiO nanowires display better gas sensitivity characteristics as compare to that of undoped, 1.6 at%, 2.1 at% and 4.3 at% Al-doped NiO nanowires. It has been investigated that the sensitivity features were upgraded with an increment on Al concentration into the crystallites based on NiO nanowires. The assimilation of Al3+ ions within NiO crystals modifies the carrier concentration by inducing changes in the chemisorbed and deficient oxygen of NiO nanowires. Hence, the incorporation of Al3+ into NiO nanowires would be a capable way for scheming and devising significant gas sensors.