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Electrochemical (EC) and photoelectrochemical (PEC) water treatment systems are gaining popularity, necessitating new electrode materials that offer reliable performance across diverse application platforms. For applications specifically targeting dilute chemical pollutants ( i.e. , parts-per-million concentrations or less), beneficial electrode properties include high surface area to overcome kinetic overpotential losses, low electrode areal electrical resistance, and high water permeability with sufficient mechanical strength for use in electroactive membrane-based treatment systems. Here, we used electrospinning to fabricate (photo)electrodes from carbon nanofibers (CNFs) containing titanium dioxide (TiO 2 ) nanoparticles. Optimal CNF/TiO 2 composites were electrochemically and photochemically active with a surface area of ∼50 m 2 g −1 and electrode areal resistance of 2.66 Ω cm 2 , values comparable to commercial carbon-based electrode materials ( e.g. , Kynol Activated Carbon Cloth). Transformation experiments with carbamazepine (CBZ), a recalcitrant organic contaminant, suggest CNF/TiO 2 electrodes function dually as sorbents, first binding CBZ prior to oxidation at positive applied potentials. Complete CBZ transformation was observed in both EC (dark) and PEC (UV light; 280 mW cm −2 ) systems over 90 minutes, with PEC systems exhibiting 1.5-fold higher transformation rates ( k obs ∼ 0.18 min −1 ) at +1.00 V ( vs. Ag/AgCl). Composite electrodes also exhibited stability across repeated use, yielding consistent current densities over five experimental cycles (120 min each) of CBZ transformation (0.25 ± 0.03 mA cm −2 ). Because of their high surface area, electrical conductivity, photoactivity, and electrochemical stability, these electrospun CNF/TiO 2 composites represent promising (photo)electrode alternatives for diverse EC and PEC applications.
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Potential of Photoelectric Stimulation with Ultrasmall Carbon Electrode on Neural Tissue: New Directions in Neurostimulation Technology Development
Abstract Neuromodulation technologies have gained considerable attention for their clinical potential in treating neurological disorders and advancing cognition research. However, traditional methods like electrical stimulation and optogenetics face technical and biological challenges that limit their therapeutic and research applications. A promising alternative, photoelectric neurostimulation, uses near‐infrared light to generate electrical pulses and thus enables stimulation of neuronal activity without genetic alterations. This study explores various design strategies to enhance photoelectric stimulation with minimally invasive, ultrasmall, untethered carbon electrodes. Employing a multiphoton laser as the near‐infrared (NIR) light source, benchtop experiments are conducted using a three‐electrode setup and chronopotentiometry to record photo‐stimulated voltage. In vivo evaluations utilize Thy1‐GCaMP6s mice with acutely implanted ultrasmall carbon electrodes. Results highlighted the beneficial effects of high duty‐cycle laser scanning and photovoltaic polymer interfaces on the photo‐stimulated voltages by the implanted electrode. Additionally, the promising potential of carbon‐based diamond electrodes are demonstrated for photoelectric stimulation and the application of photoelectric stimulation in precise chemical delivery by loading mesoporous silica nanoparticles (SNPs) co‐deposited with polyethylenedioxythiophene (PEDOT). Together, these findings on photoelectric stimulation utilizing ultrasmall carbon electrodes underscore its immense potential for advancing the next generation of neurostimulation technology.
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- Award ID(s):
- 1943906
- PAR ID:
- 10524263
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 34
- Issue:
- 41
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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