arXiv subjects

Claudio Fontanesi

Publications and source records attributed to Claudio Fontanesi.

3 recordsLinked to original sources

arXiv2026

Control of Electrons Spin Eliminates Hydrogen Peroxide Formation During Water Splitting

The production of hydrogen through water splitting in a photoelectrochemical cell suffers from an overpotential that limits the efficiencies. In addition, hydrogen-peroxide formation is identified as a competing process affecting the oxidative stability of photoelectrodes. We impose spin-selectivity by coating the anode with chiral organic semiconductors from helically-aggregated dyes as sensitizers; Zn-porphyrins and triarylamines. Hydrogen peroxide formation is dramatically suppressed, while the overall current through the cell, correlating with the water splitting process, is enhanced. Evidence for a strong spin-selection in the chiral semiconductors is presented by magnetic conducting (mc-)AFM measurements, where chiral and achiral Zn-porphyrins are compared. These findings contribute to our understanding of the underlying mechanism of spin selectivity in multiple electron-transfer reactions and pave the way towards better chiral dye-sensitized photoelectrochemical cells.

physics.chem-ph↗

arXiv2024

The Electrochemical Transistor: a device based on the Electrochemical control of a polymer Polaronic state. The PCPDT-BT as a case study

This work presents an original concept directed to implement an unconventional methodology where a device is produced by integrating a solid-state circuitry concept and an electrochemistry cell. In our experimental system an organic semiconductor, (PCPDT-BT), serves both as the gate and working electrode. Gating is obtained via electrochemical polarization exploiting a conventional three electrodes electrochemical cell placed on top of a traditional source/drain/gate solid-state device configuration. Source/drain conduction is probed via impedance measurement (electrochemical impedance spectroscopy, EIS) performed as a function of time at constant frequency, under constant potential control. The conductivity of the PCPDT-BT is due to the polaronic state induced via application of a suitable electrochemical potential (in the oxidation regime), as it is proved by infrared (IR) spectra recorded in-situ/in-operando (in attenuated under total reflection, ATR, mode) upon both electrochemical and chemical ionization/doping of the PCPDT-BT.

physics.app-ph↗

arXiv2015

Control of polymorphism in coronene by the application of magnetic fields

Coronene, a polyaromatic hydrocarbon, has been crystallized for the first time in a different polymorph using a crystal growth method that utilizes magnetic fields to access a unit cell configuration that was hitherto unknown. Crystals grown in magnetic field of 1 T are larger, have a different appearance to those grown in zero field and retain their structure in ambient conditions. We identify the new form, beta-coronene, as the most stable at low temperatures. As a result of the new supramolecular configuration we report significantly altered electronic, optical and mechanical properties.

cond-mat.mtrl-sci↗