•Focus on the preparation and electrochemical property of BDD film electrode.•Insight into the electrocatalytic process and mechanism on BDD electrodes towards pollutants.•The enhancement approaches ...towards electrochemical oxidation kinetics are included.•Other combination technologies based on electrochemical oxidation on BDD electrode are also described.•Perspectives and outlooks for BDD electrodes in electrochemical oxidation.
Boron-doped diamond (BDD) electrode has been considered as an optimal electrode material for electrochemical oxidation of organic contaminants in the aquatic environment due to its good physical and chemical properties. The fundamental research and practical application of BDD electrode in the mineralization of organic pollutants have been well developed up to now. In this review, the preparation and electrochemical properties of BDD film electrode are focused first. Then, we investigate the electrocatalytic process and degradation mechanisms on BDD electrodes based on the electrochemical oxidation of refractory pollutants in recent years. The enhancement approaches towards electrochemical oxidation kinetics are further highlighted, which include the establishment of high activity BDD electrodes and enhancement of mass transfer process during the electrochemical oxidation. Other combination technologies based on electrochemical oxidation with BDD electrode are also described to expand the application of BDD electrode in wastewater treatment. Further, the opportunity and prospective of BDD electrode are forecasted according to the existing problems in wastewater treatment.
A method for transition metal-free 1,2-carboboration of unactivated alkenes with bis(catecholato)diboron as the boron source in combination with alkyl halides as the alkyl component is introduced. ...The three-component reaction proceeds via a radical pathway on a broad range of unactivated alkenes, and the 1,2-carboboration products serve as valuable synthetic building blocks. Density functional theory calculations provide insights into the mechanism.
A nickel/N‐heterocyclic carbene catalytic system has been established for decarbonylative borylation of amides with B2nep2 by C−N bond activation. This transformation shows good functional‐group ...compatibility and can serve as a powerful synthetic tool for late‐stage borylation of amide groups in complex compounds. More importantly, as a key intermediate, the structure of an acyl nickel complex was first confirmed by X‐ray analysis. Furthermore, the decarbonylative process was also observed. These findings confirm the key mechanistic features of the acyl C−N bond activation process.
Keyed up: A Ni/N‐heterocyclic carbene (NHC) catalytic system has been established for the title reaction, which proceeds by C−N bond activation. As a key intermediate, the structure of an acyl nickel complex was confirmed by X‐ray analysis. The structure displays square‐planar geometry, stabilized by two NHC ligands in trans position. These findings confirm the key mechanistic features of the acyl C−N bond activation process. Boc=tert‐butoxycarbonyl, nep=neopentyl glycolato.
BODIPY Fluorophores for Membrane Potential Imaging Franke, Jenna M; Raliski, Benjamin K; Boggess, Steven C ...
Journal of the American Chemical Society,
08/2019, Letnik:
141, Številka:
32
Journal Article
Recenzirano
Odprti dostop
Fluorophores based on the BODIPY scaffold are prized for their tunable excitation and emission profiles, mild syntheses, and biological compatibility. Improving the water-solubility of BODIPY dyes ...remains an outstanding challenge. The development of water-soluble BODIPY dyes usually involves direct modification of the BODIPY fluorophore core with ionizable groups or substitution at the boron center. While these strategies are effective for the generation of water-soluble fluorophores, they are challenging to implement when developing BODIPY-based indicators: direct modification of BODIPY core can disrupt the electronics of the dye, complicating the design of functional indicators; and substitution at the boron center often renders the resultant BODIPY incompatible with the chemical transformations required to generate fluorescent sensors. In this study, we show that BODIPYs bearing a sulfonated aromatic group at the meso position provide a general solution for water-soluble BODIPYs. We outline the route to a suite of 5 new sulfonated BODIPYs with 2,6-disubstitution patterns spanning a range of electron-donating and -withdrawing propensities. To highlight the utility of these new, sulfonated BODIPYs, we further functionalize them to access 13 new, BODIPY-based, voltage-sensitive fluorophores (VF). The most sensitive of these BODIPY VF dyes displays a 48% ΔF/F per 100 mV in mammalian cells. Two additional BODIPY VFs show good voltage sensitivity (≥24% ΔF/F) and excellent brightness in cells. These compounds can report on action potential dynamics in both mammalian neurons and human stem cell-derived cardiomyocytes. Accessing a range of substituents in the context of a water-soluble BODIPY fluorophore provides opportunities to tune the electronic properties of water-soluble BODIPY dyes for functional indicators.
We demonstrate that polymer electron acceptors with excellent all‐polymer solar‐cell (all‐PSC) device performance can be developed from polymer electron donors by using B←N units. By alleviating the ...steric hindrance effect of the bulky pendant moieties on the conjugated polymers that contain B←N units, the π–π stacking distance of polymer backbones is decreased and the electron mobility is consequently enhanced by nearly two orders of magnitude. As a result, the power conversion efficiency of all‐PSCs with the polymer acting as the electron acceptor is greatly improved from 0.12 % to 5.04 %. This PCE value is comparable to that of the best all‐PSCs with state‐of‐the‐art polymer acceptors.
From giver to taker: Incorporation of B←N units into polymer electron donors has resulted in a series of polymer electron acceptors. Extending the length of the repeating units of the conjugated polymers alleviates the effect of steric hindrance from the pendant groups and promotes the π–π stacking of the polymer backbones. The all‐polymer solar‐cell device shows a power conversion efficiency (PCE) exceeding 5.0 %.
Photocatalytic H2O2 evolution through two‐electron oxygen reduction has attracted wide attention as an environmentally friendly strategy compared with the traditional anthraquinone or ...electrocatalytic method. Herein, a biomimetic leaf‐vein‐like g‐C3N4 as an efficient photocatalyst for H2O2 evolution is reported, which owns tenable band structure, optimized charge transfer, and selective two‐electron O2 reduction. The mechanism for the regulation of band structure and charge transfer is well studied by combining experiments and theoretical calculations. The H2O2 yield of CN4 (287 µmol h−1) is about 3.3 times higher than that of pristine CN (87 µmol h−1), and the apparent quantum yield for H2O2 evolution over CN4 reaches 27.8% at 420 nm, which is much higher than that for many other current photocatalysts. This work not only provides a novel strategy for the design of photocatalyst with excellent H2O2 evolution efficiency, but also promotes deep understanding for the role of defect and doping sites on photocatalytic activity.
Leaf‐vein‐like g‐C3N4 synthesized via a KBH4‐assisted thermal polycondensation strategy exhibits enhanced optical absorption, efficient charge carrier separation, and ample active sites, accordingly enabling excellent photocatalytic H2O2 evolution. The synergistic effect of B doping and defect sites on the improvement of catalyst performance is fully discussed by experiments and density functional theory calculations.
•Amendment of either B or Si significantly alleviated Cd accumulation and toxicity in hydroponically-cultured rice plants.•There existed strong interaction between the two elements in rice tolerance ...to Cd toxicity.•Addition of B and Si alleviated Cd-induced oxidative stress by improving antioxidative systems.•Supplement of B and Si in Cd-treated plants downregulated the expression of Cd transporter genes.
Cadmium (Cd) is a highly toxic heavy metal for both animals and plants. Rice consumption is a major source of Cd intake for human. Minimization of Cd accumulation in rice is key to reduce Cd hazard to human. Here we showed alleviating effects of boron (B), silicon (Si) and their mixture on Cd accumulation and toxicity in hydroponically-cultured rice plants. Cd treatment (100 μM) led to Cd accumulation in roots and shoots, as well as significant reduction in plant growth. However, amendment of either B or Si significantly alleviated Cd accumulation and toxicity. Moreover, simultaneous supply of B and Si showed better alleviating effect. However, addition of B and Si alleviated Cd-induced oxidative stress in Cd-treated plants as reflected by reduced MDA, H2O2 and O2−, as well as increased activities of major antioxidant enzymes. Cd exposure induced the expression of Cd transporter genes of OsHMA2, OsHMA3, OsNramp1 and OsNramp5. In contrast, simultaneous supplement of B and Si in Cd-treated plants compromised the gene expression. Our results show that both B and Si alleviate Cd accumulation and toxicity by improving oxidative stress and suppressing Cd uptake and transport, and the two elements display joint effect.
Present one‐step N2 fixation is impeded by tough activation of the N≡N bond and low selectivity to NH3. Here we report fixation of N2‐to‐NH3 can be decoupled to a two‐step process with one problem ...effectively solved in each step, including: 1) facile activation of N2 to NOx− by a non‐thermal plasma technique, and 2) highly selective conversion of NOx− to NH3 by electrocatalytic reduction. Importantly, this process uses air and water as low‐cost raw materials for scalable ammonia production under ambient conditions. For NOx− reduction to NH3, we present a surface boron‐rich core–shell nickel boride electrocatalyst. The surface boron‐rich feature is the key to boosting activity, selectivity, and stability via enhanced NOx− adsorption, and suppression of hydrogen evolution and surface Ni oxidation. A significant ammonia production of 198.3 μmol cm−2 h−1 was achieved, together with nearly 100 % Faradaic efficiency.
A two‐step process, serially integrating non‐thermal plasma technique for facile N2 to NOx− and electrocatalytic reduction for highly selective conversion of NOx− to NH3, is presented. A surface boron‐rich nickel boride electrocatalyst was developed to boost the activity, selectivity, and stability for nitrate reduction to NH3 with nearly 100 % Faradaic efficiency and low overpotential.
PDF
