▎ 摘　　要

Nanoporous Graphene Oxide (NGO) film sensor is designed by combining the modified Hummer method and the spray pyrolysis technique. The structural, morphological, and optical characterizations of the prepared NGO sensor are carried by FTIR, XRD, SEM, and UV-vis spectrophotometer. Based on the morphological study, a homogenous and uniform NGO film with two-dimensional nanoporous structure is prepared. The structural study reveals the existence of high density of oxygen functional groups on a typical GO surface with d-spacing (0) over tilde .82 nm. The optical characterization shows intensive and broad absorption band around 335 nm. The NGO film is used as a detector for CO2, H-2, C2H2 gases at room temperature (20 degrees C). The response, response and recovery times, and selectivity of the NGO sensor are investigated. Also, the effect of gases concentrations on the resistance of the film is studied. The response and selectivity of the NGO film are in order CO2 > H-2 > C2H2. The sensor response is 37.04, 16.16, and 2.87% at 60 SCCM for CO2, H-2, and C2H2, respectively. The response time is (2) over tilde5, 100, and 100 s @ 10 SCCM for CO2, H-2, and C2H2, respectively. At concentrations of 30 SCCM, the recovery time is 241.4, 437.2, and 674.7 s for C2H2, H-2, and CO2, respectively. Finally, a simple mechanism is explained to show the sensing approach. (C) 2019 The Authors. Published by Elsevier B.V.