Preparation of conjugated polymer/reduced graphene oxide nanocomposites for high-performance volatile organic compound sensors

Abstract

We have reported a facile approach to fabricate poly(3-hexylthiophene)/reduced graphene oxide (P3HT/rGO) composite films via the photoirradiation of the corresponding composite solutions. The films are applied to organic field-effect transistor (OFET) sensors for the high-performance detection of volatile organic compounds (VOCs). The photoirradiation of the composite solutions and the presence of rGO act synergistically to facilitate the molecular ordering of P3HT. Thus, the P3HT/rGO composite films containing 20 wt% rGO exhibit a maximized charge carrier mobility of similar to 0.18 cm(2) V-1 s(-1), which is 6-folds higher than that of pristine P3HT films. The interfacial interactions between rGO and P3HT are enhanced by the favorable pi-pi and electrostatic interactions following photoirradiation. The OFET sensors based on the P3HT/rGO composites consistently show enhanced sensitivity to polar VOCs (methanol, acetone, ethanol, and isopropyl alcohol) compared to those based on the pristine P3HT, photoirradiated bare P3HT, and pristine P3HT/rGO composites. In particular, the photoirradiated P3HT/rGO-based OFET sensors achieve significantly improved responsivity (similar to 110.6%) to methanol vapors (10 ppm) under rapid on/off pulses of 60 s, compared to those based on pristine P3HT (similar to 6.8%), photoirradiated bare P3HT (similar to 20.8%), and pristine P3HT/rGO (similar to 55.1%) composites. Finally, excellent response and recovery behaviors (e.g., similar to 15 s and similar to 42 s, respectively) are also observed.