Bifunctional investigation of ultra-small SnO(2) nanoparticle decorated rGO for ozone sensing and supercapacitor applications

Ultrasmall SnO(2) nanoparticles with an average size of 7 nm were synthesized by a hydrothermal method and composited with reduced graphene oxide (rGO) through an ultrasonic assisted solution process. The structural, functional, morphological and compositional properties of synthesised SnO(2) and rGO/SnO(2) were studied by XRD, FTIR, HRSEM, HRTEM, XPS and Raman analyses. The prepared materials were developed as a film over a PVA/KOH conductive layer coated substrate with varying thickness of 3, 5 and 7 μm to study their ozone sensing characteristics at room temperature. The physico-chemical properties reveal that the fabricated SnO(2) and rGO/SnO(2) nanocomposite films have a strong interaction with the ozone gas. Among the fabricated composite films rGO/SnO(2)-S1 film exhibits high ozone sensing response (38%) at room temperature. Additionally, the electrochemical performance of SnO(2) and rGO/SnO(2) nanocomposites was analysed and the rGO/SnO(2) nanocomposite exhibited higher specific capacitance (545 F g(−1)) than that of pure SnO(2) (236 F g(−1)) at a current density of 1 A g(−1) with higher cyclic stability (96%) than that of pure SnO(2) (86%) at the current density of 20 A g(−1) for a continuous 5000 charge–discharge cycles. Thus, the rGO/SnO(2) nanocomposite showed an excellent ozone sensing and energy storage performance.