Browse
Submit Data
Databases
API
Help

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Water oxidation by Ferritin: A semi-natural electrode.

ABSTRACT: Ferritin is a protein (ca. 12?nm) with a central pocket of 6?nm diameter, and hydrated iron oxide stored in this central cavity of this protein. The protein shell has a complicated structure with 24 subunits. Transmission electron microscopy images of ferritin showed nanosized iron oxides (ca. 4-6?nm) in the protein structure. In high-resolution transmission electron microscopy images of the iron core, d-spacings of 2.5-2.6?Å were observed, which is corresponded to d-spacings of ferrihydrite crystal structure. Our experiments showed that at pH 11, the modified electrode by this biomolecule is active for water oxidation (turnover frequency: 0.001?s^-1 at 1.7?V). Using affected by bacteria, we showed that Fe ions in the structure of ferritin are critical for water oxidation.

SUBMITTER: Abdi Z

PROVIDER: S-EPMC6687787 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Water oxidation by Ferritin: A semi-natural electrode.

Abdi Zahra Z Bagheri Robabeh R Song Zhenlun Z Najafpour Mohammad Mahdi MM

Scientific reports 20190808 1

Ferritin is a protein (ca. 12 nm) with a central pocket of 6 nm diameter, and hydrated iron oxide stored in this central cavity of this protein. The protein shell has a complicated structure with 24 subunits. Transmission electron microscopy images of ferritin showed nanosized iron oxides (ca. 4-6 nm) in the protein structure. In high-resolution transmission electron microscopy images of the iron core, d-spacings of 2.5-2.6 Å were observed, which is corresponded to d-spacings of ferrihydrite cry ...[more]

PMID: 31395911

Similar Datasets

Monitoring interfacial electric fields at a hematite electrode during water oxidation.

Project description:To understand the mechanisms of water oxidation on materials such as hematite it is important that accurate measurements and models of the interfacial fields at the semiconductor liquid junction are developed. Here we demonstrate how electric field induced second harmonic generation (EFISHG) spectroscopy can be used to monitor the electric field across the space-charge and Helmholtz layers in a hematite electrode during water oxidation. We are able to identify the occurrence of Fermi level pinning at specific applied potentials which lead to a change in the Helmholtz potential. Through combined electrochemical and optical measurements we correlate these to the presence of surface trap states and the accumulation of holes (h+) during electrocatalysis. Despite the change in Helmholtz potential as h+ accumulate we find that a population model can be used to fit the electrocatalytic water oxidation kinetics with a transition between a first and third order regime with respect to hole concentration. Within these two regimes there are no changes in the rate constants for water oxidation, indicating that the rate determining step under these conditions does not involve electron/ion transfer, in-line with it being O-O bond formation.

| S-EPMC10034152 | biostudies-literature

Electrocatalytic oxidation of water at a polyoxometalate nanoparticle modified gold electrode.

Project description:Spherical polyoxometalate nanoparticles, [HPMo]NPs, were synthesized from a very well known Keggin-type polyoxometalate [H3PMo12O40] in the presence of sodium dodecyl sulphate (SDS) and polyvinyl pyrrolidine (PVP) in aqueous medium and characterized by UV-Vis spectroscopy and Transmission Electron Microscopy (TEM). The [HPMo]NPs were used to modify a gold working electrode and they were characterized by SEM, EDX, elemental mapping, cyclic voltammetry and electrochemical impedance spectroscopy and applied for the electrocatalytic oxidation of water in a phosphate buffer solution at neutral pH. The modified electrode showed excellent electrocatalytic activity towards oxidation of water at an impressively low overpotential ∼350 mV with a high current density of around 1.7 mA cm-2, good stability under exhaustive electrolysis conditions and also showed long term stability.

| S-EPMC9076066 | biostudies-literature

Crossing the bridge from molecular catalysis to a heterogenous electrode in electrocatalytic water oxidation.

Project description:Significant progress has been made in designing single-site molecular Ru(II)-polypyridyl-aqua catalysts for homogenous catalytic water oxidation. Surface binding and transfer of the catalytic reactivity onto conductive substrates provides a basis for heterogeneous applications in electrolytic cells and dye-sensitized photoelectrosynthesis cells (DSPECs). Earlier efforts have focused on phosphonic acid (-PO3H2) or carboxylic acid (-CO2H) bindings on oxide surfaces. However, issues remain with limited surface stabilities, especially in aqueous solutions at higher pH under conditions that favor water oxidation by reducing the thermodynamic barrier and accelerating the catalytic rate using atom-proton transfer (APT) pathways. Here, we address the problem by combining silane surface functionalization and surface reductive electropolymerization on mesoporous, nanofilms of indium tin oxide (ITO) on fluorine-doped tin oxide (FTO) substrates (FTO|nanoITO). FTO|nanoITO electrodes were functionalized with vinyltrimethoxysilane (VTMS) to introduce vinyl groups on the electrode surfaces by silane attachment, followed by surface electropolymerization of the vinyl-derivatized complex, [RuII(Mebimpy)(dvbpy)(OH2)]2+ (12+; Mebimpy: 2,6-bis(1-methyl-1H-benzo[d]imidazol-2-yl)pyridine; dvbpy: 5,5'-divinyl-2,2'-bipyridine), in a mechanism dominated by a grafting-through method. The surface coverage of catalyst 12+ was controlled by the number of electropolymerization cycles. The combined silane attachment/cross-linked polymer network stabilized 12+ on the electrode surface under a variety of conditions especially at pH > ∼6. Surface-grafted poly12+ was stable toward redox cycling at pH ∼ 7.5 over an ∼4-h period. Sustained heterogeneous electrocatalytic water oxidation by the electrode gave steady-state currents for at least ∼6 h with a Faradaic efficiency of ∼68% for O2 production.

| S-EPMC6561241 | biostudies-literature

Covalent immobilization of oriented photosystem II on a nanostructured electrode for solar water oxidation.

Project description:Photosystem II (PSII) offers a biological and sustainable route of photochemical water oxidation to O2 and can provide protons and electrons for the generation of solar fuels, such as H2. We present a rational strategy to electrostatically improve the orientation of PSII from a thermophilic cyanobacterium, Thermosynechococcus elongatus , on a nanostructured indium tin oxide (ITO) electrode and to covalently immobilize PSII on the electrode. The ITO electrode was modified with a self-assembled monolayer (SAM) of phosphonic acid ITO linkers with a dangling carboxylate moiety. The negatively charged carboxylate attracts the positive dipole on the electron acceptor side of PSII via Coulomb interactions. Covalent attachment of PSII in its electrostatically improved orientation to the SAM-modified ITO electrode was accomplished via an amide bond to further enhance red-light-driven, direct electron transfer and stability of the PSII hybrid photoelectrode.

| S-EPMC3795471 | biostudies-literature

Dendritic core-shell nickel-iron-copper metal/metal oxide electrode for efficient electrocatalytic water oxidation.

Project description:Electrochemical water splitting requires efficient water oxidation catalysts to accelerate the sluggish kinetics of water oxidation reaction. Here, we report a promisingly dendritic core-shell nickel-iron-copper metal/metal oxide electrode, prepared via dealloying with an electrodeposited nickel-iron-copper alloy as a precursor, as the catalyst for water oxidation. The as-prepared core-shell nickel-iron-copper electrode is characterized with porous oxide shells and metallic cores. This tri-metal-based core-shell nickel-iron-copper electrode exhibits a remarkable activity toward water oxidation in alkaline medium with an overpotential of only 180?mV at a current density of 10?mA?cm-2. The core-shell NiFeCu electrode exhibits pH-dependent oxygen evolution reaction activity on the reversible hydrogen electrode scale, suggesting that non-concerted proton-electron transfers participate in catalyzing the oxygen evolution reaction. To the best of our knowledge, the as-fabricated core-shell nickel-iron-copper is one of the most promising oxygen evolution catalysts.

| S-EPMC5786058 | biostudies-literature

Preparation of Graphite-UiO-66(Zr)/Ti electrode for efficient electrochemical oxidation of tetracycline in water.

Project description:Tetracycline (TC) is widely-used antibiotic pollutant with high toxicity, refractory, persistence and bacteriostasis, and its removal from water needs to be enhanced. In this work, a novel Graphite-UiO-66(Zr)/Ti electrode was successfully prepared and evaluated for electrochemical oxidation degradation of TC. The electrochemical performance tests indicate the Graphite-UiO-66(Zr)/Ti electrode had higher electrochemical oxidation activity, which achieved higher TC removal efficiency (98.1% ± 1.5%) than Ti plate (65.2% ± 3.5%), Graphite-MIL-53(Al)/Ti electrode (79.5% ± 2.9%) and Graphite-MIL-100(Fe)/Ti electrode (89.0% ± 2.6%). The influence of operating condition was also systematically studied, and the optimized condition was pH 5.0, 20 mA/cm2 current density and 0.1 M electrolyte (Na2SO4). Through the liquid chromatography mass spectrometry (LC-MS), the TC degradation pathway by Graphite-UiO-66(Zr)/Ti electrode oxidation was proposed. Under the •OH free radical oxidative decomposition effect, the double bond, phenolic group and amine group of TC were attacked. TC was transformed into intermediate product ① (m/z = 447), then was further degraded to intermediates ② (m/z = 401) and ③ (m/z = 417). The latter was fragmented into small fractions ④ (m/z = 194), ⑤but-2-enedioic acid (m/z = 116) and ⑥oxalic acid (m/z = 90, the proposed intermediate). In addition, TC removal remained at 89.6% ± 2.7% in the sixth cycle of operation, which confirmed the efficient reusability and stability for antibiotics removal from water.

| S-EPMC9362921 | biostudies-literature

Facilitating the natural semi-drying of oily sludge by changing the form of water.

Project description:Reducing the water content of oily sludge is essential for the disposal of it. Despite conditioning and solid-liquid separation, the water content of oily sludge generally exceeds 65%. A large amount of this water exists in the form of emulsified and bound water, reducing the efficiency of water removal during the natural semi-drying process of oily sludge. To shorten the time required for natural semi-drying, this study applied an orthogonal test to screen an oily sludge modified material (OSM). The effect and mechanism of OSM on the natural semi-drying of oily sludge were studied using a thermal gravimetric analyzer (TGA), scanning electron microscope (SEM), surface tension measurement, and microscopic observations. The results show that when the ambient temperature exceeded 10°C, the OSM increased in mass by 8-10%, and the time required for the natural semi-drying of oily sludge was shortened from 15 days to less than 5 days. OSM can rupture the emulsion, reduce the surface tension, convert the emulsion and bound water in the oily sludge into free water, and accelerate the rate of water migration, diffusion, and natural evaporation from the inside of the oily sludge to the surface and air. The research results show that changing the form of water can speed up the drying of oily sludge, creating positive economic benefits in the process of oily sludge reduction and recycling.

| S-EPMC7808663 | biostudies-literature

Construction of FeCo2O4@N-Doped Carbon Dots Nanoflowers as Binder Free Electrode for Reduction and Oxidation of Water.

Project description:Electrochemical water splitting is known as a potential approach for sustainable energy conversion; it produces H2 fuel by utilizing transition metal-based catalysts. We report a facile synthesis of FeCo2O4@carbon dots (CDs) nanoflowers supported on nickel foam through a hydrothermal technique in the absence of organic solvents and an inert environment. The synthesized material with a judicious choice of CDs shows superior performance in hydrogen and oxygen evolution reactions (HER and OER) compared to the FeCo2O4 electrode alone in alkaline media. For HER, the overpotential of 205 mV was able to produce current densities of up to 10 mA cm-2, whereas an overpotential of 393 mV was needed to obtain a current density of up to 50 mA cm-2 for OER. The synergistic effect between CDs and FeCo2O4 accounts for the excellent electrocatalytic activity, since CDs offer exposed active sites and subsequently promote the electrochemical reaction by enhancing the electron transfer processes. Hence, this procedure offers an effective approach for constructing metal oxide-integrated CDs as a catalytic support system to improve the performance of electrochemical water splitting.

| S-EPMC7411927 | biostudies-literature

Lipid Oxidation Induced by RF Waves and Mediated by Ferritin Iron Causes Activation of Ferritin-Tagged Ion Channels.

Project description:One approach to magnetogenetics uses radiofrequency (RF) waves to activate transient receptor potential channels (TRPV1 and TRPV4) that are coupled to cellular ferritins. The mechanisms underlying this effect are unclear and controversial. Theoretical calculations suggest that the heat produced by RF fields is likely orders of magnitude weaker than needed for channel activation. Using the FeRIC (Ferritin iron Redistribution to Ion Channels) system, we have uncovered a mechanism of activation of ferritin-tagged channels via a biochemical pathway initiated by RF disturbance of ferritin and mediated by ferritin-associated iron. We show that, in cells expressing TRPVFeRIC channels, RF increases the levels of the labile iron pool in a ferritin-dependent manner. Free iron participates in chemical reactions, producing reactive oxygen species and oxidized lipids that ultimately activate the TRPVFeRIC channels. This biochemical pathway predicts a similar RF-induced activation of other lipid-sensitive TRP channels and may guide future magnetogenetic designs.

| S-EPMC7204511 | biostudies-literature

Assessing the trypanocidal potential of natural and semi-synthetic diketopiperazines from two deep water marine-derived fungi.

Project description:Human African trypanosomiasis (HAT, commonly known as African sleeping sickness) is categorized as a neglected disease, as it afflicts >50,000 people annually in sub-saharan Africa, and there are few formal programs in the world focused on drug discovery approaches for this disease. In this study, we examined the crude extracts of two fungal strains (Aspergillus fumigatus and Nectria inventa) isolated from deep water sediment which provided >99% growth inhibition at 1microg/mL of Trypanosoma brucei, the causative parasite of HAT. A collection of fifteen natural products was supplemented with six semi-synthetic derivatives and one commercially available compound. Twelve of the compounds, each containing a diketopiperazine core, showed excellent activity against T. brucei (IC(50)=0.002-40microM), with selectivity over mammalian cells as great as 20-fold. The trypanocidal diketopiperazines were also tested against two cysteine protease targets Rhodesain and TbCatB, where five compounds showed inhibition activity at concentrations less than 20microM. A preliminary activity pattern is described and analyzed.

| S-EPMC2893881 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data