Here we report the use of fluorescence microscopy and closed bipolar electrodes to reveal electrochemical electrocatalytic activity on large arrays. We demonstrate fluorescence-enabled (FEEM) as a new approach for imaging transient heterogeneous processes. This method uses electrode mechanism directly couple conventional oxidation reaction, e.g., ferrocene, special fluorogenic reduction reaction. The generation fluorescent product cathodic pole enables one monitor an process with optical...

Here we report the use of fast-scan cyclic voltammetry (FSCV) to study transient collision and immobilization events single electrocatalytic metal nanoparticles (NPs) on an inert electrode. In this study, a fast, repetitive voltage signal is continuously scanned ultramicroelectrode its faradaic recorded. Electrocatalytically active NPs are allowed collide immobilize electrode resulting in direct recording voltammetric response NPs. This approach enables one obtain effects catalytic as they...

The chemical complexity of single-phase multicationic oxides, commonly termed high entropy oxides (HEOs), enables the integration conventionally incompatible metal cations into a single-crystalline phase. However, few studies have effectively leveraged nature HEOs for optimization disparate physical and properties. Here, we apply HEO concept to design robust oxidation catalysts in which oxide composition is tailored simultaneously achieve catalytic activity, oxygen storage capacity, thermal...

We investigate the principle of open circuit potential (OCP) change upon a particle collision event based on mixed theory and confirmed by mimic experiment in which we studied changes OCP when two different electrodes (Pt Au) are brought into contact solution that contains some irreversible redox couples. A micrometer-sized Au ultramicroelectrode, connected parallel to Pt micro- or nanoelectrode, showed clearly measurable whose magnitude matches well with predicted simplified for pair...

A novel NaSn intermetallic improves critical electrochemical interfaces between molten sodium and NaSICON ceramic electrolyte at low temperatures (110 °C).

Addition of a Lewis acid base, NaI, to an aluminum-based ionic liquid (IL) electrolyte enables unprecedented, air-stable, reversible electrochemical cycling, attractive for energy storage.

In this technical note, we report a process in scaling down the fabrication of Au disk nanoelectrodes as small ∼4 nm radii. We have developed bottom-up approach toward individual disk-shape nanoelectrodes. This new is based upon electrochemical deposition silica nanopore electrode and involves following four steps. First, laser-assisted pulling employed to fabricate Pt nanoelectrode. Second, obtained by electrochemically etching from Third, metal nanowire deposited using template. last step,...

Here we report a new type of microelectrode sensor for single-cell exocytotic dopamine release. The microsensor is built by forming gold-nanoparticle (AuNP) network on carbon fiber microelectrode. First gold surface obtained microdisk electrode partially etching away the followed electrochemical deposition into pore. chemically functionalized with sol−gel silicate derived from (3-mercaptopropyl)trimethoxysilane (MPTS). A AuNP formed immobilizing Au nanoparticles onto thiol groups in network....

Here we report the use of Fast-Scan Cyclic Voltammetry (FSCV) to study transient nanoparticle (NP) collision experiments and determine apparent heterogeneous electron-transfer (ET) rate constant ko electrocatalytic activity single NPs. Continuous potential scanning at fast scan rates, for example, up 500 V/s, background subtraction enable voltammetric NPs when they collide on a carbon ultramicroelectrode (UME). The FSCV results indicate substantial shift in CV response due increased mass...

The cathodic dissolution of platinum, resulting from the oxygen reduction reaction (ORR) or hydrogen peroxide on has been investigated. Highly oxidizing hydroxyl radicals (OH•) are believed to be species responsible for platinum phenomenon. These produced ORR byproduct, peroxide, through a 1 electron pathway (H2O2 + e– → OH• OH–). Platinum ultramicroelectrodes (UMEs) were polarized sufficiently negative drive H2O2 surface, mainly using square wave potential pulses but constant applied and...

Three M-MOF-74 (M = Co, Mg, Ni) metal-organic framework (MOF) thin film membranes have been synthesized through a sensor functionalization method for the direct electrical detection of NO2. The two-step surface procedure on glass/Pt interdigitated electrodes resulted in terminal carboxylate group, with both steps confirmed infrared spectroscopic analysis. This allowed MOF materials to grow largely uniform manner over electrode forming membrane Pt sensing electrodes. growth each was scanning...

Chemically robust, low-power sensors are needed for the direct electrical detection of toxic gases. Metal–organic frameworks (MOFs) offer exceptional chemical and structural tunability to meet this challenge, though further understanding is regarding how coadsorbed gases influence or interfere with response. To probe competitive on trace NO2 in a simulated flue gas stream, combined structure–property study integrating synchrotron powder diffraction pair distribution function analyses was...

In the pursuit of highly stable and selective metal-organic frameworks (MOFs) for adsorption caustic acid gas species, an entire series rare earth MOFs have been explored. Each in this (RE-DOBDC; RE = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu; DOBDC 2,5-dihydroxyterepthalic acid) was synthesized tetragonal space group I4/m. Crystallized MOF samples, specifically Eu-DOBDC, were seen to a combination monodentate bidentate binding when under typical reaction conditions, resulting...

Electrodialysis (ED) desalination performance of different conventional and laboratory-scale ion exchange membranes (IEMs) has been evaluated by many researchers, but most these studies used their own sets experimental parameters such as feed solution compositions concentrations, superficial velocities the process streams (diluate, concentrate, electrode rinse), applied electrical voltages, types IEMs. Thus, direct comparison ED IEMs is virtually impossible. While use in reported,...

Open circuit potential (OCP) measurements can be very sensitive to small changes in the electrode environment and may allow detection of electron transfer events involving few, maybe single, electrons. Factors affecting overall sensitivity OCP were investigated achieve highest sensitivity. The platinum ultramicroelectrodes (UMEs) was determined solutions that initially contained only supporting electrolyte where is a mixed governed by background faradaic processes. Then, increasing amounts...

Low-temperature molten sodium batteries show remarkable promise as the kind of low-cost, large-scale, reliable energy storage technology which is key to enabling a sustainable, safe, and resilient electric grid. Here, we describe combination cathode chemistry engineered interfaces needed reduce battery operating temperature from ∼300 °C near 100 °C. This approach involves development fully molten, inorganic comprising anode, NaSICON (Na3Zr2Si2PO12) solid electrolyte separator,...

A combination of electrodeposition and thermal reduction methods have been utilized for the synthesis ligand-free FeNiCo alloy nanoparticles through a high-entropy oxide intermediate. These phases are great interest to electrocatalysis community, especially when formed by sustainable chemistry method. This is successfully achieved first forming complex five element amorphous FeNiCoCrMn (HEO) phase via from nanodroplet emulsion solution metal salt reactants. The then thermally treated reduced...

Here we report the preparation and electrochemical characterization of single Pt nanowire electrodes with radii ranging from 25 to 130 nm for their electrocatalytic activity toward oxygen reduction reaction (ORR). Ultralong nanowires were prepared by a laser pulling process. Single fabricated metal deposition lithography patterning expose just small portion (10–20 μm in length) studies. These wires characterized thoroughly using cyclic voltammetry, under potential copper, scanning electron...

Despite its promise as a safe, reliable system for grid-scale electrical energy storage, traditional molten sodium (Na) battery deployment remains limited by cost-inflating high-temperature operation. Here, we describe high-performance iodide-gallium chloride (NaI-GaCl3) salt catholyte that enables dramatic reduction in Na operating temperature from near 300°C to 110°C. We demonstrate stable, electrochemical cycling high-voltage (3.65 V) Na-NaI >8 months at Supporting this demonstration,...

Nanoporous materials, including metal–organic frameworks (MOFs) and inorganic zeolites, are gaining attention as gas sensor materials due to their chemical selectivity robustness. To advance industrial viability of these sensors, long-term, variable environment testing is needed evaluate stability continued exposure response. materials-based direct electrical readout sensors were evaluated for 3 months under dry or humid conditions at 74 °C. The comprised either Ni-MOF-74, Mg-MOF-74,...

Low-temperature molten sodium batteries comprising anodes, a NaSICON solid-state separator, and halide salt catholytes offer promise as low-cost, earth-abundant energy storage technologies. The emergence of specific, high-voltage, iodide (NaI)-based catholyte chemistry has prompted the evaluation chemical electrochemical properties salts, particularly at critical interfaces with high-performance separators. Herein, operated 110 °C NaI-AlCl3-based differing Lewis acidities were evaluated....

We report the fabrication and electrochemical response of a gold nanoband electrode located at bottom glass/epoxy nanotrench, hereafter referred to as nanotrench electrode. Gold electrodes 12.5 40 nm in width with various depths from few tens nanometers approximately 4 μm are fabricated further characterized by cyclic voltammetry. The Au follows simple etching process which small AC signal is applied an inlaid submersed NaCl solution. voltammetric behavior quasi-steady-state lower scan rates...