▎ 摘　　要

Graphene oxide (GO) and reduced graphene oxide (rGO) are important materials used for various applications like sensors, photo catalysis and supercapacitor. Herein, we present a facile approach for fabricating rGO-GO heterostructure freestanding films for gas sensing and capacitor applications. Taking advantage simple and fast laser irradiation reduction process and oxygen functional groups in the rGO-GO heterostructure, we fabricated free-standing and flexible room temperature ammonia sensors with a high response (18%) and wide sensing range (50-800 ppm). Interestingly, these heterostructures show high epsilon' (1333) in the capacitor configuration which is 24 higher than the insulating GO. Our results establish that the proposed method is a promising strategy to improve graphene-based devices like gas sensors and capacitors and also provide new insights of ultrafast laser processing of heterostructure. (C) 2018 Published by Elsevier B.V.