Resilient and Reversible Phosphotungstic Acid Passivated Zinc Anode.

Aqueous zinc ion batteries (ZIBs) present a compelling solution for grid-scale energy storage, which is crucial for integrating renewable energy resources into the electric infrastructure. The cycling stability of ZIBs hinges on the electrochemical reversibility of the zinc anode, which is often compromised by corrosion and dendritic zinc deposition. Here, we present a straightforward surface passivation strategy that significantly enhances the cycling stability of zinc anodes.

Sorption of Carbon Dioxide and Nitrogen on Porous Hyper-Cross-Linked Aromatic Polymers: Effect of Textural Properties, Composition, and Electrostatic Interactions.

Porous hyper-cross-linked aromatic polymers are one of the emerging classes of porous organic polymers with the potential for industrial application. Four different porous polymeric materials have been prepared using different precursors (indole, pyrene, carbazole, and naphthalene), and the composition and textural properties were analyzed. The materials were characterized in detail using different physicochemical techniques like scanning electron microscopy, transmission electron microscopy, nitrogen adsorption at 77 K, Fourier transform infrared spectroscopy, X-ray diffraction, etc.

Proton Conducting Organic-Inorganic Composite Membranes for All-Vanadium Redox Flow Battery.

The quest for a cost-effective, chemically-inert, robust and proton conducting membrane for flow batteries is at its paramount. Perfluorinated membranes suffer severe electrolyte diffusion, whereas conductivity and dimensional stability in engineered thermoplastics depend on the degree of functionalization. Herein, we report surface-modified thermally crosslinked polyvinyl alcohol-silica (PVA-SiO) membranes for the vanadium redox flow battery (VRFB).

Fabrication of Alkaline Electrolyzer Using Ni@MWCNT as an Effective Electrocatalyst and Composite Anion Exchange Membrane.

Here, we report the synthesis of nickel nanoparticles thermally encapsulated in multiwalled carbon nanotubes (MWCNTs) and its utility in alkaline water splitting by combining with composite thermoset anion-exchange membrane. Ni@MWCNT displayed both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). It provided 10 mA cm current density at an overpotential of 300 mV for OER and 254 mV for HER on a glassy carbon electrode, respectively.

Low-Voltage Nongassing Electroosmotic Pump and Infusion Device with Polyoxometalate-Encapsulated Carbon Nanotubes.

A low-voltage nongassing electroosmotic pump was assembled by sandwiching a silica frit between two carbon paper electrodes that were dip-coated with a paste consisting of phosphomolybdic acid/phosphotungstic acid (PMA/PTA)-encapsulated multiwalled carbon nanotubes (MWCNTs) and Nafion. The PMA/PTA encapsulation was a combined effect of their thermomigration and nanocapillary action in MWCNTs. The encapsulated MWCNTs retained desirable redox and charge transfer characteristics of PMA/PTA.

Alkaline all iron redox flow battery with a polyethylene/poly(styrene--divinylbenzene) interpolymer cation-exchange membrane.

This work describes the suitability of a polyethylene styrene-DVB based interpolymer cation exchange membrane for use in a highly alkaline redox flow battery (RFB) with a [Fe(TEA)OH]/[Fe(TEA)OH] and Fe(CN) /Fe(CN) redox couple. The alkaline stability of the membrane for 1440 h was evaluated in 5 N NaOH containing a 200 mM Fe(CN) /Fe(CN) redox couple. It was assessed according to the changes in the electrochemical and physicochemical properties.

A non-gassing electroosmotic pump with sandwich of poly(2-ethyl aniline)-Prussian blue nanocomposite and PVDF membrane.

Low voltage, non-gassing electroosmotic pump (EOP) was assembled with poly(2-ethyl aniline) (EPANI)-Prussian blue nanocomposite electrode and commercially available hydrophilic PVDF membranes. The nanocomposite material combines excellent oxidation/reduction capacity of EPANI with exceptional stability by shuttling of proton between Prussian blue nanoparticles and EPANI redox matrix. The flow rate was highly dependent on the electrode composition but it was linear with applied voltage.

Graphitic carbon coupled poly(anthraquinone) for proton shuttle flow-in-a-cell application.

Coupled electron and proton transport are an integral part of non-gassing electro-osmotic pumps (EOP). The kinetics of the electrode limits the kinetics of the electron transfer and hence the flow. This is observed in the present study with newly synthesized graphitic carbon covalently coupled to poly(anthraquinone) (PAQ).

Nongassing long-lasting electro-osmotic pump with polyaniline-wrapped aminated graphene electrodes.

An efficient nongassing electro-osmotic pump (EOP) with long-lasting electrodes and exceptionally stable operation is developed by using novel flow-through polyaniline (PANI)-wrapped aminated graphene (NH2-G) electrodes. The NH2-G/PANI electrode combines the excellent oxidation/reduction capacity of PANI with the exceptional conductivity and inertness of NH2-G. The flow rate varies linearly with voltage but is highly dependent on the electrode composition.

Chitosan-cross-linked osmium polymer composites as an efficient platform for electrochemical biosensors.

A new family of chitosan-cross-linked osmium polymer composites was prepared and its electrochemical properties were examined. The composites were prepared by quaternization of the poly(4-vinylpyridine) osmium bipyridyl polymer (PVP-Os) which was then cross-linked with chitosan, yielding PVP-Os/chitosan. Films made of the composites showed improved mass and electron transport owing to the porous and hydrophilic structure which is derived from the cross-links between the Os polymer and chitosan.

Hydroquinone modified chitosan/carbon film electrode for the selective detection of ascorbic acid.

A redox active polymer, hydroquinone modified chitosan (Q-chitosan) was synthesized and characterized by IR and (1)H NMR spectroscopy. The nanocomposite of Q-chitosan with carbon was prepared and used to construct a stable conductive film on the electrode surface. The SEM studies confirms that the Q-chitosan/C composite covers the electrode surface with polymer embedded 50 nm size carbon particles.

Mixed-valence metal oxide nanoparticles as electrochemical half-cells: substituting the Ag/AgCl of reference electrodes by CeO(2-x) nanoparticles.

Cations of mixed valence at surfaces of metal oxide nanoparticles constitute electrochemical half-cells, with potentials intermediate between those of the dissolved cations and those in the solid. When only cations at surfaces of the particles are electrochemically active, the ratio of electrochemically active/all cations is ~0.1 for 15 nm diameter CeO(2-x) particles.

A miniature, single use, skin-adhered, low-voltage, electroosmotic pumping-based subcutaneous infusion system.

A programmable, skin-attached, 36 × 30 × 8 mm system for subcutaneous infusion of 1.2 mL of a drug solution is described. The system is intended to be replaced daily.

Nafion-coating of the electrodes improves the flow-stability of the Ag/SiO2/Ag2O electroosmotic pump.

When a current or a voltage is applied across the ceramic membrane of the nongassing Ag/Ag(2)O-SiO(2)-Ag/Ag(2)O pump, protons produced in the anodic reaction 2Ag(s) + H(2)O → Ag(2)O(s) + 2H(+) + 2e(-) are driven to the cathode, where they are consumed by the reaction Ag(2)O(s) + H(2)O + 2e(-) → 2Ag(s) + 2 OH(-). The flow of water is induced by momentum transfer from the electric field-driven proton-sheet at the surface of the ceramic membrane. About 10(4) water molecules flowed per reacted electron.

A miniature, nongassing electroosmotic pump operating at 0.5 V.

Electroosmotic pumps are arguably the simplest of all pumps, consisting merely of two flow-through electrodes separated by a porous membrane. Most use platinum electrodes and operate at high voltages, electrolyzing water. Because evolved gas bubbles adhere and block parts of the electrodes and the membrane, steady pumping rates are difficult to sustain.