Realizing the Electrode Engineering Significance Through Porous Organic Framework Materials for High-Capacity Aqueous Zn-Alkaline Battery.

Energy storage technologies are eminently developed to address renewable energy utilization efficiently. Porous framework materials possess high surface area and pore volume, allowing for efficient ion transportation and storage. Their unique structure facilitates fast electron transfer, leading to improved battery kinetics.

Spatiotemporal Nitric Oxide Modulation via Electrochemical Platform to Profile Tumor Cell Response.

Nitric oxide (NO) is a gaseous molecule intricately implicated in oncologic processes, encompassing the modulation of angiogenesis and instigating apoptosis. Investigation of the antitumor effects of NO is currently underway, necessitating a detailed understanding of its cellular-level reactions. Regulating the behavior of radical NO species has been a significant challenge, primarily due to its instability in aqueous environments by rapid O-induced degradation.

Pulsed electrolysis for CO reduction: Techno-economic perspectives.

Pulsed electrolysis has emerged as a promising approach to CO reduction, offering a simple method to adjust product selectivity and enhance operational stability. However, conceptually applying the dynamic pulse operation process on a large scale highlights its differences when compared to conventional electrolysis processes, impacting the economic feasibility of the process. We discuss the influence of pulsed electrolysis on surface reaction mechanisms and the simulation of changes at both the continuum and smaller scales through computational modeling.

Defect engineered ternary metal spinel-type Ni-Fe-Co oxide as bifunctional electrocatalyst for overall electrochemical water splitting.

Transition metal spinel oxides were engineered with active elements as bifunctional water splitting electrocatalysts to deliver superior intrinsic activity, stability, and improved conductivity to support green hydrogen production. In this study, we reported the ternary metal Ni-Fe-Co spinel oxide electrocatalysts prepared by defect engineering strategy with rich and deficient Na ions, termed NFCO-Na and NFCO, which suggest the formation of defects with Na forming tensile strain. The Na-rich NiFeCoO spinel oxide reveals lattice expansion, resulting in the formation of a defective crystal structure, suggesting higher electrocatalytic active sites.

Iridium-Cooperated, Symmetry-Broken Manganese Oxide Nanocatalyst for Water Oxidation.

The water oxidation reaction, the most important reaction for hydrogen production and other sustainable chemistry, is efficiently catalyzed by the MnCaO cluster in biological photosystem II. However, synthetic Mn-based heterogeneous electrocatalysts exhibit inferior catalytic activity at neutral pH under mild conditions. Symmetry-broken Mn atoms and their cooperative mechanism through efficient oxidative charge accumulation in biological clusters are important lessons but synthesis strategies for heterogeneous electrocatalysts have not been successfully developed.

Electrochemical Nitrogen Fixation for Green Ammonia: Recent Progress and Challenges.

Ammonia, a key feedstock used in various industries, has been considered a sustainable fuel and energy storage option. However, NH production via the conventional Haber-Bosch process is costly, energy-intensive, and significantly contributing to a massive carbon footprint. An electrochemical synthetic pathway for nitrogen fixation has recently gained considerable attention as NH can be produced through a green process without generating harmful pollutants.

Mechanistic investigation of electrocatalytic reductive amination at copper electrode.

Reductive amination has been widely used for manufacturing carbon-nitrogen-containing building blocks. Despite its versatility, the need for a chemical reductant or harmful hydrogen gas has limited its further utilization in modern chemical applications. Here, we report electrochemical reductive amination (ERA) to pursue sustainable synthetic routes.

Tuning Single-Atom Dopants on Manganese Oxide for Selective Electrocatalytic Cyclooctene Epoxidation.

Selective and efficient electrocatalysts are imperative for the successful deployment of electrochemistry toward synthetic applications. In this study, we used galvanic replacement reactions to synthesize iridium-decorated manganese oxide nanoparticles, which showed a cyclooctene epoxidation partial current density of 10.5 ± 2.

Directing transition metal-based oxygen-functionalization catalysis.

This review presents the recent progress of oxygen functionalization reactions based on non-electrochemical (conventional organic synthesis) and electrochemical methods. Although both methods have their advantages and limitations, the former approach has been used to synthesize a broader range of organic substances as the latter is limited by several factors, such as poor selectivity and high energy cost. However, because electrochemical methods can replace harmful terminal oxidizers with external voltage, organic electrosynthesis has emerged as greener and more eco-friendly compared to conventional organic synthesis.

Electrochemical Modulation of Carbon Monoxide-Mediated Cell Signaling.

Despite the critical role played by carbon monoxide (CO) in physiological and pathological signaling events, current approaches to deliver this messenger molecule are often accompanied by off-target effects and offer limited control over release kinetics. To address these challenges, we develop an electrochemical approach that affords on-demand release of CO through reduction of carbon dioxide (CO ) dissolved in the extracellular space. Electrocatalytic generation of CO by cobalt phthalocyanine molecular catalysts modulates signaling pathways mediated by a CO receptor soluble guanylyl cyclase.

Effects of paramagnetic fluctuations on the thermochemistry of MnO(100) surfaces in the oxygen evolution reaction.

We investigated the effects of paramagnetic (PM) fluctuations on the thermochemistry of the MnO(100) surface in the oxygen evolution reaction (OER) using the "noncollinear magnetic sampling method plus U" (NCMSM+U). Various physical properties, such as the electronic structure, free energy, and charge occupation, of the MnO(100) surface in the PM state with several OER intermediates, were reckoned and compared to those in the antiferromagnetic (AFM) state. We found that PM fluctuation enhances charge transfer from a surface Mn ion to each of the intermediates and strengthens the chemical bond between them, while not altering the overall features, such as the rate determining step and resting state, in reaction pathways.

Spectroscopic capture of a low-spin Mn(IV)-oxo species in Ni-MnO nanoparticles during water oxidation catalysis.

High-valent metal-oxo moieties have been implicated as key intermediates preceding various oxidation processes. The critical O-O bond formation step in the Kok cycle that is presumed to generate molecular oxygen occurs through the high-valent Mn-oxo species of the water oxidation complex, i.e.

In situ electrochemical generation of nitric oxide for neuronal modulation.

Understanding the function of nitric oxide, a lipophilic messenger in physiological processes across nervous, cardiovascular and immune systems, is currently impeded by the dearth of tools to deliver this gaseous molecule in situ to specific cells. To address this need, we have developed iron sulfide nanoclusters that catalyse nitric oxide generation from benign sodium nitrite in the presence of modest electric fields. Locally generated nitric oxide activates the nitric oxide-sensitive cation channel, transient receptor potential vanilloid family member 1 (TRPV1), and the latency of TRPV1-mediated Ca responses can be controlled by varying the applied voltage.

Probing the Structure and Binding Mode of EDTA on the Surface of MnO Nanoparticles for Water Oxidation by Advanced Electron Paramagnetic Resonance Spectroscopy.

Identification of the surface structure of nanoparticles is important for understanding the catalytic mechanism and improving the properties of the particles. Here, we provide a detailed description of the coordination modes of ethylenediaminetetraacetate (EDTA) on MnO nanoparticles at the atomic level, as obtained by advanced electron paramagnetic resonance (EPR) spectroscopy. Binding of EDTA to MnO leads to dramatic changes in the EPR spectrum, with a 5-fold increase in the axial zero-field splitting parameter of Mn(II).

Epoxidation of Cyclooctene Using Water as the Oxygen Atom Source at Manganese Oxide Electrocatalysts.

Epoxides are useful intermediates for the manufacture of a diverse set of chemical products. Current routes of olefin epoxidation either involve hazardous reagents or generate stoichiometric side products, leading to challenges in separation and significant waste streams. Here, we demonstrate a sustainable and safe route to epoxidize olefin substrates using water as the oxygen atom source at room temperature and ambient pressure.

Highly Selective Active Chlorine Generation Electrocatalyzed by CoO Nanoparticles: Mechanistic Investigation through in Situ Electrokinetic and Spectroscopic Analyses.

The reaction mechanism of electrochemical chloride oxidation at neutral pH is different from that at acidic pH, in which a commercial chlor-alkali process has been developed. Different proton concentrations and accelerated hydrolysis of the generated chlorine into hypochlorous acid at high pH can change the electrokinetics and stability of reaction intermediates. We have investigated a unique reaction mechanism of CoO nanoparticles for chloride oxidation at neutral pH.

Efficient Water Splitting Cascade Photoanodes with Ligand-Engineered MnO Cocatalysts.

The band edge positions of semiconductors determine functionality in solar water splitting. While ligand exchange is known to enable modification of the band structure, its crucial role in water splitting efficiency is not yet fully understood. Here, ligand-engineered manganese oxide cocatalyst nanoparticles (MnO NPs) on bismuth vanadate (BiVO) anodes are first demonstrated, and a remarkably enhanced photocurrent density of 6.

Quantitative Analysis of Calcium Phosphate Nanocluster Growth Using Time-of-Flight Medium-Energy-Ion-Scattering Spectroscopy.

One of the remaining challenges in material chemistry is to unveil the quantitative compositional/structural information and thermodynamic nature of inorganic materials especially in the initial nucleation and growth step. In this report, we adopted newly developed time-of-flight medium-energy-ion-scattering (TOF-MEIS) spectroscopy to address this challenge and explored heterogeneously grown nanometer-sized calcium phosphate as a model system. With TOF-MEIS, we discovered the existence of calcium-rich nanoclusters (Ca/P ∼ 3) in the presence of the non-collagenous-protein-mimicking passivating ligands.

Amorphous Cobalt Phyllosilicate with Layered Crystalline Motifs as Water Oxidation Catalyst.

The development of a high-performance oxygen evolution reaction (OER) catalyst is pivotal for the practical realization of a water-splitting system. Although an extensive search for OER catalysts has been performed in the past decades, cost-effective catalysts remain elusive. Herein, an amorphous cobalt phyllosilicate (ACP) with layered crystalline motif prepared by a room-temperature precipitation is introduced as a new OER catalyst; this material exhibits a remarkably low overpotential (η ≈ 367 mV for a current density of 10 mA cm ).

Design Principle and Loss Engineering for Photovoltaic-Electrolysis Cell System.

The effects of exchange current density, Tafel slope, system resistance, electrode area, light intensity, and solar cell efficiency were systematically decoupled at the converter-assisted photovoltaic-water electrolysis system. This allows key determinants of overall efficiency to be identified. On the basis of this model, 26.

Sulfur-Modified Graphitic Carbon Nitride Nanostructures as an Efficient Electrocatalyst for Water Oxidation.

There is an urgent need to develop metal-free, low cost, durable, and highly efficient catalysts for industrially important oxygen evolution reactions. Inspired by natural geodes, unique melamine nanogeodes are successfully synthesized using hydrothermal process. Sulfur-modified graphitic carbon nitride (S-modified g-CN ) electrocatalysts are obtained by annealing these melamine nanogeodes in situ with sulfur.

Current Status and Bioinspired Perspective of Electrochemical Conversion of CO to a Long-Chain Hydrocarbon.

Electrocatalytic conversion of CO into a long-chain hydrocarbon represents an important research direction in adding value to CO-based chemicals and realizing its practical application. Long-chain hydrocarbons may change the current fossil fuel-based industry in that those chemicals have a similar energy density as gasoline, high compatibility with the current infrastructure, and low hydroscopicity for pipeline distribution. However, most of the electrocatalysts produce C, C, and C chemicals, and methods for producing long-chain hydrocarbons are not available thus far.

Mechanistic Investigation of Water Oxidation Catalyzed by Uniform, Assembled MnO Nanoparticles.

The development of active water oxidation catalysts is critical to achieve high efficiency in overall water splitting. Recently, sub-10 nm-sized monodispersed partially oxidized manganese oxide nanoparticles were shown to exhibit not only superior catalytic performance for oxygen evolution, but also unique electrokinetics, as compared to their bulk counterparts. In the present work, the water-oxidizing mechanism of partially oxidized MnO nanoparticles was investigated using integrated in situ spectroscopic and electrokinetic analyses.

Cold-spray coating of hydroxyapatite on a three-dimensional polyetheretherketone implant and its biocompatibility evaluated by in vitro and in vivo minipig model.

PEEK is a bioinert material that does not chemically bind to native bone tissue and thus formation of natural bone-like hydroxyapatite (HA) coating layer on PEEK has been an important challenge to improve biocompatibility and to preserve mechanical property of PEEK. Among various coating techniques, cold-spray coating method is suitable to form stable HA coating layer on PEEK while maintaining their chemical properties, because it can be conducted in relatively low-temperature range. Therefore, in this research, we used cold-spray coating method to form a thick layer of HA on the topographically complex PEEK substrates with periodic ridges on the surface and implanted in iliac bone defects of minipigs which is known to be similar with human body system.