We present platinum nanoparticles dispersed wrinkled graphene-like carbon-wrapped carbon nanotubes (Pt/GCNTs) as a room temperature chemiresistive hydrogen gas sensor. Pt nanoparticles are decorated over GCNTs surface using poly (sodium 4-styrene sulfonate) (PSS) functionalization, followed by ethylene glycol reduction method. The highly defective wrinkled graphene-like surface of GCNTs provides large surface area and PSS functionalization provides stable immobilization of mono dispersed Pt nanoparticles on the carbon surface. A simple and inexpensive drop cast technique is used to fabricate the thick film sensor of the material. Hydrogen resistive gas sensing properties of Pt/GCNTs are studied at different gas concentrations, temperatures and Pt wt. % loadings. Pt/GCNTs sensor shows optimal sensitivity at room temperature with stable and reproducible response towards hydrogen. The sensor with 2 wt. % of Pt showed maximum sensitivity that is three fold higher than Pt decorated carbon nanotubes (Pt/CNTs) with the same Pt wt. % loading. The present study shows potential to explore novel H2 sensors. © 2018 Hydrogen Energy Publications LLC

Sundara Ramaprabhu

Department Of Physics

- Jaidev

Mridula Baro

carbon

Carbon nanotubes

Chemical detection

Ethylene

Ethylene glycol

GAS DETECTORS

Gases

Graphene

Hydrogen

Metal nanoparticles

Sensors

Thick films

Yarn

GAS SENSING PROPERTIES

HYDROGEN GAS

HYDROGEN GAS SENSING

HYDROGEN GAS SENSORS

Maximum sensitivity

OPTIMAL SENSITIVITY

Platinum nano-particles

POLY(SODIUM 4-STYRENESULFONATE)

Platinum

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

International Journal of Hydrogen Energy

Room temperature hydrogen gas sensing properties of mono dispersed platinum nanoparticles on graphene-like carbon-wrapped carbon nanotubes

Multi-edged wrinkled graphene-like carbon-wrapped carbon nanotubes (GWC) is demonstrated as a Pt-free counter electrode for dye-sensitized solar cells (DSSCs). GWC, with wrinkled graphene-like surface and one-dimensional tubular structure, exhibits significant electrocatalytic activity toward the reduction of triiodide due to the highly defective multi-edges and good conductivity. Raman spectroscopy studies suggest the presence of significantly higher defects in the GWC sample in comparison to multi-walled carbon nanotubes (MWNTs) and hydrogen exfoliated graphene (HEG). Four-probe measurement studies show better specific resistance (11.30 Ω cm), sheet resistance (4.52 × 103 Ωsq−1), and conductivity (8.84 Sm−1) of GWC film compared to HEG, but less compared to MWNTs. The impact of GWC properties on DSSC performance is studied by cyclic voltammetry and electrochemical impedance spectroscopy. The GWC counter electrode shows enhanced catalytic activity and power conversion efficiency (6.15 %) compared to that of MWNTs (5.12 %) and HEG (5.42 %). We also compare the catalytic activity and power conversion efficiency of GWC with Pt and find approaching that of Pt (6.68 %). © 2014, Springer Science+Business Media Dordrecht.

Journal of Nanoparticle Research

Multi-edged wrinkled graphene-like carbon-wrapped carbon nanotubes and highly conductive Pt-free counter electrode for dye-sensitized solar cells

Chemical and electrical synergies between graphite oxide and multiwalled carbon nanotube (MWNT) for processing graphene wrapped-MWNT hybrids has been realized by chemical vapor deposition without any chemical functionalization. Potential of the hybrid composites have been demonstrated by employing them as electrocatalyst supports in proton exchange membrane fuel cells. The defects present in the polyelectrolyte, which have been wrapped over highly dispersed MWNT, act as anchoring sites for the homogeneous deposition of platinum nanoparticles. Single-cell proton exchange membrane fuel cells show that the power density of the hybrid composite-based fuel cells is higher compared to the pure catalyst-support-based fuel cells, because of enhanced electrochemical reactivity and good surface area of the nanocomposites. © 2012 American Chemical Society.

ACS Applied Materials and Interfaces

Pt nanoparticle-dispersed graphene-wrapped MWNT composites as oxygen reduction reaction electrocatalyst in proton exchange membrane fuel cell

Hybrid carbon nanostructures consisting of graphene nanoplatelets (GNPs) interspersed with multiwalled carbon nanotubes (MWCNTs) were synthesized by solution phase mixing of their parent aqueous dispersions. To further arrest the aggregation of GNPs, crystalline nanoparticles of a noble metal (Pt) were dispersed in situ by chemical reduction. This ensemble of the metal decorated hybrid structure was solubilized using Nafion and a simple drop casting method was employed to fabricate the sensor. In addition to the remarkable stability and repeatability, the sensor also showed an enhanced sensitivity of ∼17% to a low concentration of 4 vol.% hydrogen in air, at room temperature. The improved sensitivity due to Nafion solubilization could be explained by a dual mechanism of hydrogen dissociation. Variations in the sensor properties with change in hydrogen concentrations and temperature were studied. The kinetics of hydrogen adsorption in the sensor could be well explained by the Avrami-Erofeev model. From the Arrhenius plot of the rate constants, the activation energy was determined to be ∼24 kJ/(mol H). Effect of morphology of the bare hybrid structure was systematically investigated by varying the weight ratios of GNPs and MWCNTs. © 2010 Elsevier Ltd. All rights reserved.

Carbon

Hybrid carbon nanostructured ensembles as chemiresistive hydrogen gas sensors

A unique method for synthesis of graphene wrapped carbon nanotubes was developed by chemical vapor deposition. Raman analyses show that defects have been created during growth which helps in the efficient dispersion of the composites in a variety of solvents. The synergistic combination of 2D graphene and 1D carbon nanotubes with high electrical conductivity (30 S m-1) can be exploited for energy and sensing applications. © 2011 The Royal Society of Chemistry.

Journal of Materials Chemistry

Facile synthesis of one dimensional graphene wrapped carbon nanotube composites by chemical vapour deposition

Journal	Data powered by TypesetInternational Journal of Hydrogen Energy
Publisher	Data powered by TypesetElsevier Ltd
ISSN	03603199
Open Access	No