Multiwalled Carbon Nanotube-Polystyrene Composite Modified Pt Electrode as an Electrochemical Gas Sensor (original) (raw)
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Material Science & Engineering International Journal, 2020
This paper reported the results of application of screen printed electrodes (SPE) based on polymer/carbon nanostructures (multi wall carbon nanotubes – MWCNT and grapheme – G) for gas sensors. Commercial SPEs were modified by polymers such as conductive polymer Poly Vinylidene Fluorid – PVDF and biocompatible Poly Ethylene Glycol – PEG. Modified SPEs were tested in ammonia vapors with different concentration: 3, 6.2, 12.5 and 25% (wt.). Sensor-testing was performed by monitoring the change in the electrical resistance of the electrodes. The physical characterization of the sensing electrodes was performed by Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) in ATR mode. The surface morphology of CNT/PEG and CNT/ PVDF modifications, after coating with 25% NH3, expressed the effects of ammonia on the surface of the nanocomposite layer. The ammonia solution acts aggressively on the modified surface, causing furrows to form in the uniform structure and very small nanorods of oxides.
Electrochemically Functionalized Single-Walled Carbon Nanotube Gas Sensor
Electroanalysis, 2006
We demonstrate a facile fabrication method to make chemical gas sensors using single-walled carbon nanotubes (SWNT) electrochemically functionalized with polyaniline (PANI). The potential advantage of this method is to enable targeted functionalization with different materials to allow for creation of high-density individually addressable nanosensor arrays. PANI-SWNT network based sensors were tested for on-line monitoring of ammonia gas. The results show a superior sensitivity of 2.44% DR/R per ppm v NH 3 (which is more than 60 times higher than intrinsic SWNT based sensors), a detection limit as low as 50 ppb v , and good reproducibility upon repeated exposure to 10 ppm v NH 3 . The typical response time of the sensors at room temperature is on the order of minutes and the recovery time is a few hours. Higher sensitivities were observed at lower temperatures. These results indicate that electrochemical functionalization of SWNTs provides a promising new method of creating highly advanced nanosensors with improved sensitivity, detection limit, and reproducibility.
Robust fabrication of selective and reversible polymer coated carbon nanotube-based gas sensors
Sensors and Actuators B: Chemical, 2010
In this study, a systematic investigation was carried out to produce reliable and reproducible polymer coated nanotube sensors to enhance their selectivity against exposed analyte molecules. To do this, a series of uniformly distributed, randomly aligned SWNT films were prepared via vacuum filtration from suspended HiPCO nanotubes and transferred to photolithography patterned silicon chips with high reproducibility and yield. The SWNT film density was optimized for detection of dimethyl methylphosphonate and ammonia at the percolation threshold range of nanotube electric conductance. Cyclic voltammetry (CV) was used to polymerize seven different polymers in aqueous solutions and coat a thin layer onto optimized SWNT films. Polymer coated SWNT-based sensors were analyzed for selectivity for a variety of gases. Results indicate that the electropolymerization of different polymers onto nanotube surfaces can be a simple and promising way to obtain controlled, reliable, and modulated response for various analyte molecules.
Pt nanoparticle-supported multiwall carbon nanotube electrodes for amperometric hydrogen detection
Sensors and Actuators B-chemical, 2011
Pt nanoparticles decorated Multi-walled carbon nanotubes (MWCNTs) electrode fabricated by wet chemical deposition is demonstratedly excellent candidate for application in amperometric hydrogen sensors. Structural and morphological characterizations have been carried out using SEM/EDS, TEM and XRD. Cyclic voltammogram method was used to investigate electrocatalytic behaviors toward hydrogen oxidation of the as-prepared electrode. Sensor measurements were implemented under an amperometric short-circuit condition. Influences of MWCNTs content, H 2 PtCl 6 concentration, NaBH 4 concentration and drying temperature to performance of hydrogen sensing were evaluated. A maximum sensitivity of about 216 μA ppm -1 was measured. The obtained Pt NPs-decorated MWCNTs electrode had a linear relationship between response current and hydrogen concentration in the wide detecting range from 5 to 1000 ppm. The Pt NPs-decorated MWCNTs electrode also exhibited a higher selectivity toward hydrogen species, than it did toward carbon monoxide species compared to the Pt-ZnO/MWCNTs, Pt-Ni/MWCNTs, Pt-Zn/MWCNTs and Pt-Pd/MWCNTs electrodes. Furthermore, the short respond and recovery times of this composite electrode in sensing hydrogen were displayed.
Journal of Sensors, 2012
Miniaturized gas-sensing devices that use single-walled carbon nanotubes as active material have been fabricated using two different electrode materials, namely, Au/Cr and NbN. The resistive sensors have been assembled aligning by dielectrophoresis the nanotube bundles between 40 μm spaced Au/Cr or NbN multifinger electrodes. The sensing devices have been tested for detection of the H2S gas, in the concentration range 10–100 ppm, using N2as carrier gas. No resistance changes were detected using sensor fabricated with NbN electrodes, whereas the response of the sensor fabricated with Au/Cr electrodes was characterized by an increase of the resistance upon gas exposure. The main performances of this sensor are a detection limit for H2S of 10 ppm and a recovery time of few minutes. The present study suggests that the mechanism involved in H2S gas detection is not a direct charge transfer between molecules and nanotubes. The hypothesis is that detection occurs through passivation of the...
TOPICAL REVIEW: Recent progress in carbon nanotube-based gas sensors
Nanotechnol, 2008
The development of carbon nanotube-(CNTs-)based gas sensors and sensor arrays has attracted intensive research interest in the last several years because of their potential for the selective and rapid detection of various gaseous species by novel nanostructures integrated in miniature and low-power consuming electronics. Chemiresistors and chemical field effect transistors are probably the most promising types of gas nanosensors. In these sensors, the electrical properties of nanostructures are dramatically changed when exposed to the target gas analytes. In this review, recent progress on the development of different types of CNT-based nanosensors is summarized. The focus was placed on the means used by various researchers to improve the sensing performance (sensitivity, selectivity and response time) through the rational functionalization of CNTs with different methods (covalent and non-covalent) and with different materials (polymers and metals).
Recent progress in carbon nanotube-based gas sensors
Nanotechnology, 2008
The development of carbon nanotube-(CNTs-)based gas sensors and sensor arrays has attracted intensive research interest in the last several years because of their potential for the selective and rapid detection of various gaseous species by novel nanostructures integrated in miniature and low-power consuming electronics. Chemiresistors and chemical field effect transistors are probably the most promising types of gas nanosensors. In these sensors, the electrical properties of nanostructures are dramatically changed when exposed to the target gas analytes. In this review, recent progress on the development of different types of CNT-based nanosensors is summarized. The focus was placed on the means used by various researchers to improve the sensing performance (sensitivity, selectivity and response time) through the rational functionalization of CNTs with different methods (covalent and non-covalent) and with different materials (polymers and metals).
Poly(m-aminobenzene sulfonic acid) functionalized single-walled carbon nanotubes based gas sensor
Nanotechnology, 2007
We have demonstrated a NH 3 , NO 2 and water vapour sensor based on poly(m-aminobenzene sulfonic acid) functionalized single-walled carbon nanotube (SWNT-PABS) networks. The SWNT-PABS based sensors were fabricated by simple dispersion of SWNT-PABS on top of pre-fabricated gold electrodes. SWNT-PABS sensors showed excellent sensitivity with ppb v level detection limits (i.e., 100 ppb v for NH 3 and 20 ppb v for NO 2 ) at room temperature. The response time was short and the response was totally reversible. The sensitivity could be tuned by adjusting the sensor initial resistance. The sensors were also suitable for monitoring relative humidity in air.
Journal of the Electrochemical Society, 2012
This paper reports the decoration of single wall carbon nanotubes (SWCNTs) with platinum (Pt) nanoparticles using an electrochemical technique, rotating disk slurry electrode (RoDSE). Pt/SWCNTs were electrochemically characterized by cyclic voltammetry technique (CV) and physically characterized through the use of transmission electron microscopy (TEM), energy dispersive spectroscopy - X-ray florescence (EDS-XRF) and X-ray diffraction (XRD). After characterization it was found that electrodeposited nanoparticles had an average particle size of 4.1 ± 0.8 nm. Pt/SWCNTs were used as sensing material for methane (CH4) detection and showed improved sensing properties in a range of concentration from 50 ppm to 200 ppm parts per million (ppm) at room temperature, when compared to other Pt/CNTs-based sensors. The use of this technique for the preparation of Pt/SWCNTs opens a new possibility in the bulk preparation of samples using an electrochemical method and thus their potential use in a ...