Sonochemical synthesis of PEDOT:PSS intercalated ammonium vanadate nanofiber composite for room-temperature NH3 sensing

Abstract

Until now, the synthesis of cationic vanadate nanofibers/conducting polymers composites have required template such as surfactants and electrochemical equipment for the coating of conducting polymers. The cationic vanadate nanofibers have been synthesized by complex methods to overcome the low electrical conductivity of bulk vanadium oxide (V2O5). However, in some cases a reaction time of at least 10 h is needed. In this study, for the first time, Poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) intercalated ammonium vanadate ((NH4)2V6O16∙1.5H2O) nanofiber (AVNF) composites were synthesized in 4 h using a simple sonochemical method for NH3 gas sensing studies. In addition, chemical composition, crystal morphologies and structures changes of the nanofiber composites according to the intercalation of ammonium cation and PSS:PEDOT were investigated. The NH3 gas sensing results reveal that the fabricated PEDOT:PSS-AVNF composite sensor had higher sensitivity and shorter response time to NH3 gas than V2O5, PEDOT, AVNF, and PEDOT-AVNF sensors at room temperature (24 °C). The enhanced NH3 sensitivity was mainly attributed to enhanced electrical conductivity (4.5 × 10−2 S. cm-1), high surface area, and p-p heterojunctions formed between the PEDOT:PSS and AVNF. The results obtained in this research demonstrate the beneficial effects of intercalating PEDOT:PSS in AVNF for NH3 gas sensing.