Glass-Fabric Reinforced Ag Nanowire/Siloxane Composite Heater Substrate: Sub-10 nm Metal@Metal Oxide Nanosheet for Sensitive Flexible Sensing Platform

摘要

The development of flexible chemiresistors is imperative for real-time monitoring of air quality and/or human physical conditions without space constraints. However, critical challenges such as poor sensing characteristics, vulnerability under toxic chemicals, and weak reliability hinder their practical use. In this work, for the first time, an ultrasensitive flexible sensing platform is reported by assembling Pt loaded thin-layered (≈10 nm) SnO_2 nanosheets (Pt-SnO_2 NSs) based 2D sensing layers on Ag nanowires embedded glass-fabric reinforced vinyl-phenyl siloxane hybrid composite substrate (AgNW-GFRVPH film) as a heater. The thermally stable AgNW-GFRVPH film based heater is fabricated by free radical polymerization of vinyl groups in vinyl-phenyl oligosiloxane and phenyltris(dimethylvinylsiloxy) silane with Ag NW and glass-fabric, showing outstanding heat generation (≈200 °C), high dimensional stability (13 ppm °C~(-1)), and good thermal stability (≈350 °C). The Pt-SnO_2 NSs, which are synthesized by calcination of Sn precursor coated graphene oxide (GO) sheets and subsequent Pt functionalization, exhibit high mechanical flexibility and superior response (R_(air)/R_(gas) = 4.84) to 1 ppm level dimethyl sulfide. Taking these advantages, GO-templated oxide NSs combined with a highly stable AgNW-GFRVPH film heater exhibits the best dimethyl sulfide sensing performance compared to state-of-the-art flexible chemiresistors, enabling them as a superior flexible gas sensing platform.