Search results for " nanostructure"

Nickel-Indium Sulphide Core-Shell Nanostructures Obtained by Spray-ILGAR Deposition

2013

Ni nanowires (NWs) of different lengths were fabricated by pulsed potentiostatic deposition within pores of polycarbonate membranes. After template dissolution, substrates underwent sequential Spray-ILGAR (R) depositions of thin indium sulphide films. The effect of deposition temperature was also investigated. For low number of deposition cycles, results showed complete and uniform covering of metal over the entire length of NWs, with formation of Ni - In2S3 core-shell structures. However, with increasing number of deposition cycles films became uneven and crusty, especially at higher temperatures, owing to the simultaneous formation of nickel sulfide. This drawback was almost eliminated do…

Nanostructured anode material for Li-ion battery obtained by galvanic process

2016

This work focused on the synthesis and characterization of nanostructured lead hydroxide chloride (PbOHCl) that is an innovative anode material for lithium-ion batteries (LIBs). In particular, we have obtained nanostructures of mixed PbOHCl and lead metal, directly into the pores of a commercially available alumina membrane, acting as template. The process was based on galvanic displacement reaction that was carried out in a two-compartment electrochemical cell without the use of an external power supply. This simple and cheap procedure gives regular array of Pb/PbOHCl composite nanowires. To obtain nanostructured electrodes is a significant result because, it’s well known that nanostructur…

Nanostructured Pb electrode for innovative lead-acid battery

2017

Lead-acid batteries are widely used for energy storage, due to a well-established and reliable technology. Over the years, various studies for improving the performance of this battery have been performed. The main goal is to replace conventional plates with innovative electrodes having good stability, high capacity and high surface area. In particular, it is necessary to improve the kinetics of electrochemical conversion reactions at the electrode-solution interface, and to guarantee good electrical continuity during repeated charge/discharge cycles. To achieve these goals, the attention was focused on nanostructured electrodes. Up-to-date, two principal approaches have been followed. In t…

Electrodeposition and characterization of Mo oxide nanostructures

2015

Template electrodeposition has been used to grow uniform arrays of molybdenum oxide nanostructures in polycarbonate membrane. Several parameters have been investigated, like electrodeposition, time and solution pH. These parameters do not influence the nature of the deposit that always consists of mixed valence molybdenum oxides, whereas the nanostructure morphology changes with pH. In particular, at low pH (2.7), nanotubes are formed, whilst arrays of nanowires are obtained above pH 5.5. This change of morphology is likely due to H2 bubbles evolution during the electrochemical deposition, particularly occurring at low pH. It was found that fast removal of H2 bubbles through vigorous stirri…

Fabrication and characterization of nanostructured Ni and Pd electrodes for hydrogen evolution reaction (HER) in water-alkaline electrolyzer

2017

In the field of water-alkaline electrolyzer, the development of nanoporous low cost nickel electrodes is one of the potential approaches to increase electrocatalytic activity. Template electrodeposition is a facile and cheap technique for obtaining Ni nanowires (NWs) with high surface area. These nanostructures were fabricated by a two-step procedure. In the first step, a Ni compact layer was deposited on one side of the template where a gold film was previously sputtered, while, in the second-step, an ordered array of Ni-NWs was obtained by electrodeposition inside the template channels. The NWs were firmly connected to the underlying Ni layer, acting as a current collector. In order to en…

Growth and Electrochemical Performance of Lead and Lead Oxide Nanowire Arrays as Electrodes for Lead-Acid Batteries

2013

n this work, we present the growth and electrochemical performance of nanostructured lead and lead oxide electrodes for lead-acid batteries. The electrodes were obtained by template electrodeposition in polycarbonate membranes, acting as template. Electrochemical tests were conducted at constant current in 5M aqueous solution of sulphuric acid, after assembling nanostructured lead and lead oxide electrodes in a zero-gap configuration using a commercially available separator. The main advantages of these electrodes are the high specific energy and power density, and the wide surface area, about 70 times higher than the geometrical one. These features allowed high discharge rates, up to 20C. …

Sn-Co Nanowires: High-Performing Electrodes as Anodes for Lithium-ion Batteries

2012

Alcohol-Selective Oxidation in Water under Mild Conditions via a Novel Approach to Hybrid Composite Photocatalysts

2015

Abstract The oxidation of alcohols to carbonyl compounds in a clean fashion (i.e., with water as a solvent or under solvent‐free conditions, and using O2 or H2O2 as the primary oxidant) is the subject of considerable research efforts. A new approach for the selective oxidation of soluble aromatic alcohols in water under mild conditions via a novel composite photocatalyst has been developed. The catalyst is synthesized by grafting 4‐(4‐(4‐hydroxyphenylimino)cyclohexa‐2,5dienylideneamino)phenol and silver nanoparticles onto the surface of moderately crystalline titanium dioxide. The titanium dioxide‐based composite was first extensively characterized and then employed in the catalytic oxidati…

Strong field phenomena: Atoms, Molecules, Nanostructures.

Experimental Procedures of Accelerated Aging and Evaluation of Effectiveness of Nanostructured Products for the Protection of Volterra (Italy) Panchi…

2022

The aims of the research were to evaluate the effectiveness of the application of nanostructured products on Volterra calcarenite stone and to define the experimental conditions and procedures of accelerated aging tests, able to simulate different degradation on the studied lithotype. The work focused on methods of performing accelerated aging tests in order to simulate different effects of environmental decay involving stone used on a historical site. The rock samples were examined before and after three treatment types: cyclic salt spray chamber, cycles of freezing–thawing and cycles of thermal shock. After each artificial aging cycle, changes in appearance were noted and chemical and phy…