Highly sensitive hydrogen gas sensor based on Al-doped SnO2/Polyaniline composite nanofibers

Department of Physics, Polymer Nanotech Laboratory, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur 440033, India

Adv. Mater. Lett., 2018, 9 (3), pp 182-187

DOI: 10.5185/amlett.2018.1591

Publication Date (Web): May 16, 2018

Copyright © IAAM-VBRI Press

E-mail: sbkondawar@yahoo.co.in

Abstract

Metal oxide nanofibers showed keen interest in chemical gas sensing due to their unique chemical and electrical properties at operating temperature more than 200 ^oC. Their sensitivity can be improved at low operating temperature closed to room temperature by using conducting polymers. In this paper, Al doped tin oxide/polyaniline composite nanofibers detected H₂ molecules at room temperature. A simple versatile electrospinning technique is used for the fabrication of Aluminium (Al) doped (tin oxide) SnO₂ nanofibers and polyaniline was encapsulated using chemical oxidative polymerization (COP) of aniline monomer using ammonium persulfate as redox initiator. The structure and morphology of Al-doped SnO₂/PANI composite nanofibers were investigated by SEM-EDX, UV-VIS and XRD spectroscopy. Structural changes of SnO₂/PANI crystal due to the incorporation of Al³⁺ ions have been explained. Al-doped SnO₂/PANI composite nanofiber is very much selective towards H₂ gas molecules in terms of high sensitivity, rapid response and recovery around room temperature compared to that of Al-doped SnO₂. The present sensing mechanism systematically explained the existence of PN junction which is formed by p-type and n-type semiconductors in Al-doped SnO₂/PANI hybrid composite material.

Keywords

Al-doped SnO₂ nanofibers, Polyaniline, Composites,p-n heterojunction, Hydrogen gas sensor.