Functionalized multiwalled carbon nanotubes (CNTs) are coated with a 4–5 nm thin layer of V2O5 by controlled hydrolysis of vanadium alkoxide. The resulting V2O5/CNT composite has been investigated for electrochemical activity with lithium ion, and the capacity value shows both faradaic and capacitive (nonfaradaic) contributions. At high rate (1 C), the capacitive behavior dominates the intercalation as 2/3 of the overall capacity value out of 2700 C/g is capacitive, while the remaining is due to Li-ion intercalation. These numbers are in agreement with the Trasatti plots and are corroborated by X-ray photoelectron spectroscopy (XPS) studies on the V2O5/CNTs electrode, which show 85% of vanadium in the +4 oxidation state after the discharge at 1 C rate. The cumulative high-capacity value is attributed to the unique property of the nano V2O5/CNTs composite, which provides a short diffusion path for Li+-ions and an easy access to vanadium redox centers besides the high conductivity of CNTs. The composite arc...

V2O5-Anchored Carbon Nanotubes for Enhanced Electrochemical Energy Storage

Carbon-based nanomaterials for removal of chemical and biological contaminants from water: A review of mechanisms and applications

Highly hydroxylated carbon fibres as electrode materials of all-vanadium redox flow battery

Because of their heterogeneous nature, supported metal catalysts always contain metal centers in a rather broad dispersion range, and the presence of even atomically dispersed metals has been reported on oxide supports. The role of the atomically dispersed metal centers in the overall catalytic performances of these supported metal catalysts, however, has not been addressed to date. In this study, temperature programmed reaction and scanning transmission electron microscopy experiments were applied to show the fundamentally different reactivity patterns exhibited by Pd metal in atomically dispersed and traditional 3D clusters in the demanding reaction of CO2 reduction. The requirement for two different catalyst functionalities in the reduction of CO2 with hydrogen on Pd/Al2O3 and Pd/MWCNT catalysts was also substantiated. The results obtained clearly show that the oxide support material, even when it is considered inert like Al2O3, can function as a critical, active component of complex catalyst systems.

A.G. Osorio

Papers

H2SO4/HNO3/HCl—Functionalization and its effect on dispersion of carbon nanotubes in aqueous media

Effect of surface area of substrates aiming the optimization of carbon nanotube production from ferrocene

Glass foam of high compressive strength produced from photovoltaic module waste glass, eggshell, and clay