The electrochemical reduction of α-nitrocumene in a protic and basic medium on large surface area (porous) electrodes: electronation-protonation or electrocatalytic hydrogenation?

1999 ◽  
Vol 77 (5-6) ◽  
pp. 687-694 ◽  
Author(s):  
Elisa Soazara Chan-Shing ◽  
Denys Boucher ◽  
Jean Lessard

The electrochemical reduction of α-nitrocumene (1) has been investigated under controlled potential, at a mercury pool cathode and at Raney metal (Raney nickel, Raney cobalt and Devarda copper) and fractal nickel electrodes in basic aqueous ethanol. A comparison of the product distribution from the reduction at Hg (electronation-protonation (EP) mechanism) and that from the reduction at Raney metals and fractal nickel has shown that both the electrocatalytic hydrogenation (ECH) and EP mechanisms can be involved at large surface area (porous) transition metal electrodes in a basic protic medium. Cyclic voltammetry was used to determine the reduction potential of 1 at Hg and at bright polycrystalline nickel, cobalt, and copper cathodes in the same medium.Key words: electrocatalytic hydrogenation, electroreduction, 2-nitro-2-phenylpropane, Raney metal cathodes, mechanism.

2008 ◽  
Vol 1127 ◽  
Author(s):  
Franchessa Maddox ◽  
Catherine Cook ◽  
Leigh McKenzie ◽  
Brenda O'Neil ◽  
Elizabeth A. Junkin ◽  
...  

ABSTRACTVery high surface area nanostructured metal electrodes are of interest as efficient current collectors. For thin film devices, the nanostructured metal can be grown in place using electrodeposition or electroless deposition. For larger devices metal electrodes structured at more than one length scale are desirable. Self-assembling surfactant templates are a versatile method of generating a range of nanostructures. As we report here, electrodeposition of nickel, cobalt and copper from liquid crystalline solutions of Triton X-100 produces a number of nanostructures, with significant surface area increases. Electrodeposition into templates with microstructure has proven more demanding. Oil-in-water Microemulsions of Tween surfactants and soy oil, produce micrometer scale structures, however measured nickel surface area does not scale with sample thickness. The method is also not robust, and was found to give microstructures only for nickel and cobalt. Experiments show that under our conditions a combination of nickel metal, nickel acetate and nickel/detergent microstructures are formed.


2009 ◽  
Vol 1214 ◽  
Author(s):  
Nikolas Cordes ◽  
Martin Bakker

AbstractSupercapacitors and advanced batteries capable of rapid charge and discharge need conductive three dimensional porous electrodes. The high conductivities of porous metal electrodes are attractive. However, the surface areas of such electrodes are still well short of those achievable in carbon. One approach to formation of high surface area porous metal electrodes is to electrodeposit metal into nanostructured templates on 3-D scaffolds such as nickel foam. By careful control of composition and voltage thin films of mesoporous silica can be deposited onto these 3-D templates. Removal of the templating surfactant produces a very high surface area mesoporous coating. Metal can then be plated into the mesoporous silica, which, after removal of the silica, leaves a high surface area 3-D porous electrode.


Author(s):  
Mengke Wang ◽  
Jun Zhu ◽  
You Zi ◽  
Zheng-Guang Wu ◽  
Haiguo Hu ◽  
...  

In recent years, two-dimensional (2D) black phosphorus (BP) has been widely applied in many fields, such as (opto)electronics, transistors, catalysis and biomedical applications due to its large surface area, tunable...


Author(s):  
Chunmei Tang ◽  
Xiaoxu Wang ◽  
Shengli Zhang

Two-dimensional MXene nanomaterials are promising anode materials for Li-ion batteries (LIBs) due to their excellent conductivity, large surface area, and high Li capability.


2019 ◽  
Vol 11 (1) ◽  
pp. 38-54 ◽  
Author(s):  
Anand Maurya ◽  
Anurag Kumar Singh ◽  
Gaurav Mishra ◽  
Komal Kumari ◽  
Arati Rai ◽  
...  

Since the development of first lipid-based nanocarrier system, about 15% of the present pharmaceutical market uses nanomedicines to achieve medical benefits. Nanotechnology is an advanced area to meliorate the delivery of compounds for improved medical diagnosis and curing disease. Nanomedicines are gaining significant interest due to the ultra small size and large surface area to mass ratio. In this review, we discuss the potential of nanotechnology in delivering of active moieties for the disease therapy including their toxicity evidences. This communication will help the formulation scientists in understanding and exploring the new aspects of nanotechnology in the field of nanomedicine.


2021 ◽  
Vol 875 ◽  
pp. 160034
Author(s):  
Na Liu ◽  
Fan Fan ◽  
Wei Xu ◽  
Hao Zhang ◽  
Qi Zhou ◽  
...  

Nanoscale ◽  
2017 ◽  
Vol 9 (46) ◽  
pp. 18311-18317 ◽  
Author(s):  
Yuan Gao ◽  
Yuanjing Lin ◽  
Zehua Peng ◽  
Qingfeng Zhou ◽  
Zhiyong Fan

Three-dimensional interconnected nanoporous structure (3-D INPOS) possesses high aspect ratio, large surface area, as well as good structural stability. Profiting from its unique interconnected architecture, the 3-D INPOS pseudocapacitor achieves a largely enhanced capacitance and rate capability.


Author(s):  
Rohit Karnik ◽  
Chuanhua Duan ◽  
Kenneth Castelino ◽  
Rong Fan ◽  
Peidong Yang ◽  
...  

Interesting transport phenomena arise when fluids are confined to nanoscale dimensions in the range of 1–100 nm. We examine three distinct effects that influence ionic and molecular transport as the size of fluidic channels is decreased to the nanoscale. First, the length scale of electrostatic interactions in aqueous solutions becomes comparable to nanochannel size and the number of surface charges becomes comparable to the number of ions in the channel. Second, the size of the channel becomes comparable to the size of biomolecules such as proteins and DNA. Third, large surface area-to-volume ratios result in rapid rates of surface reactions and can dramatically affect transport of molecules through the channel. These phenomena enable us to control transport of ions and molecules in unique ways that are not possible in larger channels. Electrostatic interactions enable local control of ionic concentrations and transport inside nanochannels through field effect in a nanofluidic transistor, which is analogous to the metal-oxide-semiconductor field effect transistor. Furthermore, by controlling surface charge in nanochannels, it is possible to create a nanofluidic diode that rectifies ionic transport through the channel. Biological binding events result in partial blockage of the channel, and can thus be sensed by a decrease in nanochannel conductance. At low ionic concentrations, the effect of biomolecular charge is dominant and it can lead to an increase in conductance. Surface reactions can also be used to control transport of molecules though the channel due to the large surface area-to-volume ratios. Rapid surface reactions enable a new technique of diffusion-limited patterning (DLP), which is useful for patterning of biomolecules and surface charge in nanochannels. These examples illustrate how electrostatic interactions, biomolecular size, and surface reactions can be used for controlling ionic and molecular transport through nanochannels. These phenomena may be useful for operations such as analyte focusing, pH and ionic concentration control, and biosensing in micro- and nanofluidic devices.


Sign in / Sign up

Export Citation Format

Share Document