title: Electrolytically exfoliated graphene-loaded flame-made Ni-doped SnO2 composite film for acetone sensing.
abstract: In this work, flame-spray-made SnO2 nanoparticles are systematically studied by doping with 0.1-2 wt % nickel (Ni) and loading with 0.1-5 wt % electrolytically exfoliated graphene for acetone-sensing applications. The sensing films (∼12-18 μm in thickness) were prepared by a spin-coating technique on Au/Al2O3 substrates and evaluated for acetone-sensing performances at operating temperatures ranging from 150 to 350 °C in dry air. Characterizations by X-ray diffraction, transmission/scanning electron microscopy, Brunauer-Emmett-Teller analysis, X-ray photoelectron spectroscopy and Raman spectroscopy demonstrated that Ni-doped SnO2 nanostructures had a spheriodal morphology with a polycrystalline tetragonal SnO2 phase, and Ni was confirmed to form a solid solution with SnO2 lattice while graphene in the sensing film after annealing and testing still retained its high-quality nonoxidized form. Gas-sensing results showed that SnO2 sensing film with 0.1 wt % Ni-doping concentration exhibited an optimal response of 54.2 and a short response time of ∼13 s toward 200 ppm acetone at an optimal operating temperature of 350 °C. The additional loading of graphene at 5 wt % into 0.1 wt % Ni-doped SnO2 led to a drastic response enhancement to 169.7 with a very short response time of ∼5.4 s at 200 ppm acetone and 350 °C. The superior gas sensing performances of Ni-doped SnO2 nanoparticles loaded with graphene may be attributed to the large specific surface area of the composite structure, specifically the high interaction rate between acetone vapor and graphene-Ni-doped SnO2 nanoparticles interfaces and high electronic conductivity of graphene. Therefore, the 5 wt % graphene loaded 0.1 wt % Ni-doped SnO2 sensor is a promising candidate for fast, sensitive and selective detection of acetone.
authors.affiliation: Department of Physics and Materials Science, Faculty of Science, Chiang Mai University , Chiang Mai 50202, Thailand.
authors.forename: Suparat
authors.initials: S
authors.lastname: Singkammo
authors.forename: Anurat
authors.initials: A
authors.lastname: Wisitsoraat
authors.forename: Chakrit
authors.initials: C
authors.lastname: Sriprachuabwong
authors.forename: Adisorn
authors.initials: A
authors.lastname: Tuantranont
authors.forename: Sukon
authors.initials: S
authors.lastname: Phanichphant
authors.forename: Chaikarn
authors.initials: C
authors.lastname: Liewhiran
keywords: Ni-doping; SnO2; acetone; flame spray pyrolysis; gas sensor; graphene