Iridium Oxide Redox Gradient Material: Operando X‑ray Absorption of Ir Gradient Oxidation States during IrOx Bipolar Electrochemistry
24 August 2021
Electrodeposited iridium oxide (K1.7IrO0.8 (OH)2.2 × 1.8 H2O; also called IrOx) is among the best substrates for neural growth, decreasing impedance and stimulating cell growth, when used as a connected electrode. Without direct contact, it has been proven to stimulate neurons through a bipolar mechanism related to the conducting character of the material in the presence of remote electric fields.
The remote wireless electrostimulation that arises from it is of large significance in clinical applications. Ionic intercalation simultaneous with iridium oxidation state changes at the induced IrOx cathode and the formation of a redox and ionic gradient at the IrOx substrate is envisaged as the most probable explanation for the observed effects on neural cell growth. This work shows the iridium state gradient using X-ray absorption spectroscopy (XAS) with significant electrochemical features and relaxation times that allow for a persistent effect in the material even after the electric field creating the induced dipole is switched off. It also shows correlated intercalated sodium gradients observed by semiquantitative energy-dispersive X-ray (EDX) analysis data. The bipolar effect is proven and yields new evidence for the behavior of other biocompatible neural growth substrates.
Hits: 571
Sustainable energy conversion & storage systems

Iridium Oxide Redox Gradient Material: Operando X‑ray Absorption of Ir Gradient Oxidation States during IrOx Bipolar Electrochemistry

Laura Fuentes-RodriguezLlibertat AbadLaura SimonelliDino Tonti, and Nieves Casañ-Pastor

J. Phys. Chem. C 2021,
Publication Date:July 27, 2021
DOI: 10.1021/acs.jpcc.1c05012

Also at ICMAB

  • Ultrafast Interface Charge Separation in Carbon Nanodot–Nanotube Hybrids

    18 January 2022 111 hit(s) Biomaterials
    Carbon dots are an emerging family of zero-dimensional nanocarbons behaving as tunable light harvesters and photoactivated charge donors. Coupling them to carbon nanotubes, which are well-known electron acceptors with excellent charge transport capabilities, is very promising for several applications.
  • Interfaces and Interphases in Ca and Mg Batteries

    14 January 2022 134 hit(s) Energy
    The development of high energy density battery technologies based on divalent metals as the negative electrode is very appealing. Ca and Mg are especially interesting choices due to their combination of low standard reduction potential and natural abundance.
  • Giant Thermal Transport Tuning at a Metal / Ferroelectric Interface

    27 December 2021 253 hit(s) Energy
    Interfacial thermal transport plays a prominent role in the thermal management of nanoscale objects and is of fundamental importance for basic research and nanodevices. At metal/insulator interfaces, a configuration commonly found in electronic devices, heat transport strongly depends upon the effective energy transfer from thermalized electrons in the metal to the phonons in the insulator.
  • Polylactide, Processed by a Foaming Method Using Compressed Freon R134a, for Tissue Engineering

    17 December 2021 244 hit(s) Biomaterials
    Fabricating polymeric scaffolds using cost-effective manufacturing processes is still challenging. Gas foaming techniques using supercritical carbon dioxide (scCO2) have attracted attention for producing synthetic polymer matrices; however, the high-pressure requirements are often a technological barrier for its widespread use. Compressed 1,1,1,2-tetrafluoroethane, known as Freon R134a, offers advantages over CO2 in manufacturing processes in terms of lower pressure and temperature conditions and the use of low-cost equipment.
  • Storing energy with molecular photoisomers

    14 December 2021 317 hit(s) Energy
    The global energy demand continues to grow both due to the increasing population and wealth. As one of the potential solutions, renewable energy resources can relieve the pressure on conventional energy sources. However, due to fluctuations in both supply and demand, they need to be complemented with load-leveling technologies.

INSTITUT DE CIÈNCIA DE MATERIALS DE BARCELONA, Copyright © 2020 ICMAB-CSIC | Privacy Policy | This email address is being protected from spambots. You need JavaScript enabled to view it.