Platform for nanoscale Electrochemical Synthesis and Characterizations based on Atomic force microscope (PESCA)

Responsabile dell'Attrezzatura

PESCA platform consists in the combination of AFM (with nm resolution) with an electrochemical set-up. This combination  affords simultaneous acquisition of different

types of images (topological activity of electrified surface and correlation with applied electrical potential) unveiling fundamental interfacial properties at nm range

with redox processes examined at the  site of electron transfer.The availability of in situ and in operando techniques in  PESCA 
 allows the characterization of the polarized surface while surface is imaged with the result of attaining the
mapping of different physical properties.PESCA is a set-up that retrieves high resolution images for quantitative mapping via analysis
of detected AFM signal and correlation with the desired physical parameter.PESCA realizes at the sub-microscopic level what other
tools achieve on macroscopic scale,but with the addition of high sensitivity at the nm level,  lateral resolution and high speed of acquisition.PESCA requires very
small size of probed volume of material (as any AFM) and is adequate to the length scale of nanomaterials. Beside opening a new
level of comprehension of the electrochemical phenomena, PESCA presents the absolute novelty of upgrading and expanding the capabilities of
microscopes for the measurement of the mechanical and electrical forces at the nm level  in a non-invasive and non-destructive way. This is particularly attractive  in
the field of metrology concerning the subfields of nanomechanics and nanoelectrostatics. As far as nanomechanical properties are concerned, PESCA is

 fully suitable to analyze soft samples (low range of elastic moduli).  PESCA works as
contact resonance AFM (CR-AFM), in which the resonance of the cantilever in contact with sample surface is analyzed and measures the local
value of sample indentation modulus.CR-AFM is used to analyze samples with elastic modulus ranging from tens of MPa,
e.g.,cells,soft polymers, to hundreds of GPa, e.g. stiff coatings and crystals.In viscoelastic measurements,
cantilever oscillation modes are analyzed to evaluate resonance frequencies and the corresponding quality factors. In PESCA the cantilever is

 excited with accurate selection of the oscillation frequency to avoid spurious signals exploiting the  photothermal effect provoked by
a  laser impinging on the back of the cantilever pulsed at the desired frequency.This results in astonishing narrow spectral
bands around the selected frequency, with a dramatic improvement not only of the speed of tapping mode morphological reconstruction
but also on the accuracy of nanomechanical images. In PESCA the use of photothermal excitation to perform viscoelastic mapping represents
the state of the art in the field of nanomechanical characterizations. Since PESCA affords the imaging of surfaces under electrical polarization,  the occurrence of

electrochemical redox processes in immobilized systems brings about the change of spin state and of electronic magnetic moment in the system undergoing an electron transfer 
process.For this type of transformations the magnetic characterizations at the nm scale magnetic force microscopy (MFM) is well-established and is combined with PESCA.

in a way that impedes the creation of  electrostatic artifacts hampering the accurate evaluation of the magnetic properties of samples thanks to an action of decoupling.

After decoupling, MFM data can be used to image the true distribution of magnetic domains on sample, and to evaluate the magnetic moment or magnetization of single
nanoparticles on sample surface.In this context the simultaneous use of Kelvin probe force microscopy (KPFM, which is also addable to PESCA), which nullifies the
tip-sample bias at each point of the scan,and MFM, which locally nullifies electrostatic tip-sample interactions, is very
effective. KPFM-MFM represents the state of art in nanomagnetic characterizations  is customarily included in PESCA platform.

ERC scientific sector
Anno di collaudo
Stato dell'attrezzatura
In fase di acquisizione
Nome e acronimo del laboratorio o locale che ospita l'attrezzatura
Laboratorio di microscopia elettrochimica (PESCA Lab)_ATOM infrastructure
CU014 - Chimica - Cannizzaro Scienze Matematiche Fisiche e Naturali
Parole chiave
materials science (all)
Servizi offerti
PESCA allows surface imaging at high spatial resolution when the substrate is an electrode of an electrochemical (EC) cell while recording locally different physical properties. This type of investigative tool can be adopted in many different areas of research in electrochemistry. Within this first ambit PESCA can be usefully employed in Energy (batteries, fuel cells, supercapacitors, electrochromic devices, primary cells, solar conversion devices), in Corrosion and Surface Science, Coatings Technology, EC Engineering, EC Synthesis, Electrodeposition, Metallurgy, Electroanalysis and Sensors. Moreover, electrochemically induced transformations at the nm level of control can also consist in the modification of surface physical properties like optical absorption, dielectric permittivity, magnetic susceptibility of the electrode, molecular adsorption, or in the application of mechanical stress (electrodeposition with interphases growth on the electrode). Because of that, an electrochemical process at an electrode can be also exploited for the realization of switching operations that can be quite different in their nature, e.g. controlled release of chemicals (drugs, reactants, etching agents) from a functionalized surface or in the control of radiation transmission properties in a material. Given the direct involvement of switching processes in smart materials and devices in a broad range of applications, it is envisaged that PESCA analysis will be profitable in many advanced technologies and fabrication processes. Systems characterized by PESCA can be of interest in telecommunication engineering, optics, computer science, sensing devices, surface protection/treatment, medicine, biochemistry, food science, catalysis beside all the branches directly involving Electrochemistry. The last group of applications can attract the attention of the research groups that are active in molecular medicine, biochemical science, but also in archeology as far archeometry and preservation of cultural heritage are concerned. It has to be outlined that the type of information PESCA can afford has an intrinsically interdisciplinary character. Thanks to the capability of PESCA of unveiling and understanding the mechanisms of electrode modification at the microscopic level under operative conditions, there will be an considerable improvement of the electrode performance control and a re-definition of the function of an electrically polarized surface with relevant and unexpected consequences in many different fields of scientifica research.

© Università degli Studi di Roma "La Sapienza" - Piazzale Aldo Moro 5, 00185 Roma