Electrospinning Encapsulation of Pd Nanoparticles into α-Fe2O3 Nanofibers Windows Enhanced Acetone Sensing

Abstract

Different concentrations (0, 1 mol%, 2 mol%, 6 mol% and 8 mol%) of palladium (Pd) nanoparticles modified hematite nanofibers (Pd NPs@ α-Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> NFs) were successfully synthesized via a facile electrospinning method followed by the calcination treatment. Their surface morphologies, crystal structures and chemical compositions were subsequently characterized in order to find optimum modification percentage. The gas sensing experiments on Pd NPs@ α-Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -based gas sensors revealed that encapsulation of Pd NPs into α-Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> NFs could significantly improve their sensing performances. Specifically, the as-prepared Pd <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> /Fe gas sensor exhibited higher response ( R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">air</sub> /R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gas</sub> = 16.6) toward 100 ppm acetone at 220°C, which was 3.4 times higher than that of Pd <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> /Fe sensor (4.89). Meanwhile, the Pd <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> /Fe sensor also showed shorter response/recovery (4 s/4 s), low limit of detection (LOD) (50 ppb) and good selectivity and long-term stability. The enhanced gas sensing properties of Pd NPs@ α-Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -based gas sensors could be attributed to the chemical and electronic sensitization of Pd NPs.