Stable and sensitive amino-functionalized graphene/polyaniline nanofiber composites for room-temperature carbon dioxide sensing

Abstract

This article describes the preparation and characterization of amino-functionalized graphene (AmG)/ polyaniline (PANI)/poly(methyl methacrylate) (PMMA) nanofiber mats along with the efficiency of these nanofiber composites as a new material for sensing carbon dioxide (CO 2 ) gas. The surfaces of the PMMA nanofibers were treated at room temperature by ultraviolet (UV) radiation. AmG/PANI was then deposited on the surfaces of the PMMA nanofibers via chemical oxidative polymerization. It was concluded that UV radiation reduced the hydrophobicity of the PMMA surface through introducing oxidized groups onto the surface. The electrical response of the gas sensor based on the composite nanofibers was investigated at room temperature using various concentrations of CO 2 gas. Compared to the PANI/PMMA nanofibers, the AmG/PANI nanofiber composites displayed a better electrical resistance response to CO 2 at room temperature; the AmG/PANI nanofiber composites exhibited higher sensitivity and faster response times under the same conditions. Fig. 1 (a) An SEM image of PMMA nanofibers and the distribution of their diameters (the inset shows an SEM image at higher magnification). (b) An SEM image of PMMA after the deposition of AmG/PANI. (c) An SEM image of PMMA after UV treatment and the distribution of PMMA fiber diameters (the inset shows an SEM image with higher magnification). (d) An SEM image of PMMA nanofibers after UV treatment and the deposition of AmG/PANI. This journal is

Nanofibers of Polyaniline and Cu(II)–l-Aspartic Acid for a Room-Temperature Carbon Monoxide Gas Sensor

“…44 As seen, the intensity of the peak at ∼857 nm is enhanced by an increasing amount of Cu(II)−L-Asp nanofibers, which provides strong evidence for the higher conductivity of the nanofibers composite. 14,17 Considering that there is no oxygen element in the PANI structure, all of these changes can be attributed to Cu(II)−L-aspartic acid nanofibers when it was introduced in the composite, besides the PANI. By considering the result, interaction through CO and CO− OH with the amine group of PANI is more likely.…”

“…Roy and co-workers 17 have fabricated a PANI/multiwalled carbon nanotube nanocomposite for CO detection at room temperature using in situ polymerization. Abdali et al 14 synthesized an amino-functionalized graphene/PANI/PMMA nanofiber for sensing of CO 2 at room temperature. When aminefunctionalized graphene is combined with PANI, its superior sensing properties can improve the sensitivity, stability, and selectivity of the resulting sensor.…”

“…26 Particularly, the highly selective gas adsorption properties of MOFs were reported extensively. 14 Contrary to a wide investigation on CO adsorption/storage-based MOFs, few studies have been done on MOF-based CO sensors. Lv and coworkers explored Ni-MOF-74 crystals as a resonant− gravimetric sensor for highly sensitive detection of CO. 27 The chemiresistive CO sensors based on MOFs are also rare.…”

“…Although aniline hydrochloride and its derivatives can be considered pollutants, it has to be used as a precursor to synthesize PANI because of the outstanding advantages of PANI sensors. As the chemical state of PANI changes after the doping or adsorption process, its electrical conductivity is easily modified. , In this regard, Kashyap and co-workers investigated the sensing performance of a film of PANI nanofibers deposited on a silicon substrate toward various volatile organic compound (VOC) molecules, including methanol, ethanol, toluene, chloroform, and acetone. They stated that the sensing process is based on the acceptance of the free electron that exists in the reduced VOC molecules by the polaron present inside the PANI chain, accompanied by an increase in the electrical resistance of the PANI film.…”

“…The change of chemical and physical properties of MOF upon analyte uptake has been used to detect environmental contaminants, including heavy metals, organic compounds, volatiles, and toxic gases . Particularly, the highly selective gas adsorption properties of MOFs were reported extensively . Contrary to a wide investigation on CO adsorption/storage-based MOFs, few studies have been done on MOF-based CO sensors.…”