Herein, we report the fabrication of hydrogen gas sensors based on noble nanometal decorated one dimensional multi walled carbon nanotubes and two dimensional graphene by a simple drop casting technique, with practical applications in view. Pt decorated functionalized graphene sheets (Pt/f-G) and Pt decorated functionalized multi walled carbon nanotubes (Pt/f-MWNT) were synthesized and employed as hydrogen sensors. Systematic investigation of hydrogen sensing, at a low detection level of 4 vol% hydrogen in air, of (Pt/f-G) reveals a response time comparable to that of (Pt/f-MWNT) but with a two fold increase in the sensitivity at room temperature. These sensors were also found to be stable over repeated cycles of hydrogenation and dehydrogenation.
Herein, we report a preparation method of a novel binary hybrid nanocomposite based on polyaniline (PANI) and a-MnO 2 nanotubes (MNTs) by in situ polymerization. The polymerization is carried out in acidic medium using a-MnO 2 nanotubes as oxidant. A symmetrical supercapacitor is fabricated and the electrochemical performance of the supercapacitor is investigated by cyclic voltammetry (CV), chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS) techniques using 1.0 M H 2 SO 4 as electrolyte. The nanocomposite shows maximum specific capacitance of 626 F g À1 and corresponding energy density of 17.8 W h kg À1 , as calculated from the charge-discharge curve at a specific current density of 2 A g À1 in the potential range 0-0.7 V.
Nanostructured platinum dispersed on functionalized graphene and functionalized multiwalled carbon nanotube [Pt/(f-G-f-MWNT)] hybrid nanomaterials, a unique combination of three-, two, and one-dimensional structures, were used as an electrocatalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cell (PEMFC). Electrochemical studies performed on Pt/(f-G-f-MWNT) composite materials by varying the ratio of the composition of f-G and f-MWNT for the investigation of the electrochemical active surface area (ECSA) have resulted in an ECSA as high as
108normalm2/g
for the Pt dispersed on nanocomposite containing equal proportions of f-G and f-MWNT. Polarization graphs for the ORR reaction in PEMFC with Pt/(f-G-f-MWNT) as an electrocatalyst resulted in the best performance of
540mW/cm2
for the
Pt/(50wt%f-G+50wt%f-MWNT)
cathode catalyst, agreeing with the electrochemical active surface area of Pt, due to good accessibility and uniform dispersion of the nanostructured Pt catalyst dispersed on the f-G-f-MWNT catalyst support, making them a suitable electrocatalyst for advanced PEMFC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.