Borohydrides

硼氢化物
  • 文章类型: Journal Article
    近几十年来,利用硼氢化物(B-NZVI)合成的纳米零价铁被广泛应用于环境修复。然而,硼在增强B-NZVI的固有反应性方面的贡献及其在去除六价铬[Cr(VI)]方面的有效性尚未得到很好的认识和量化。据我们所知,在这里,首次证明了B-NZVI的核-壳结构,其特征是氧化铁壳下方的Fe-B合金壳。合金硼可以降低H+,在B-NZVIs的酸消化过程中产生超过35.6%的H2。此外,合金B在Cr(VI)去除过程中为Fe3还原提供电子,防止反应性颗粒表面的原位钝化。同时,B-NZVI的无定形氧化物壳表现出增加的缺陷密度,促进壳外Fe2+的释放以减少Cr(VI),形成层状结构的沉淀物和强烈的Fe-O键。因此,B-NZVI的表面积归一化容量和表面反应速率比NZVI晶体高6.5和6.9倍,分别。这项研究揭示了合金B在使用B-NZVI去除Cr(VI)中的重要性,并提出了一种全面的方法来研究B-NZVI去除污染物所涉及的电子途径和机制。
    Nanoscale zerovalent iron synthesized using borohydride (B-NZVI) has been widely applied in environmental remediation in recent decades. However, the contribution of boron in enhancing the inherent reactivity of B-NZVI and its effectiveness in removing hexavalent chromium [Cr(VI)] have not been well recognized and quantified. To the best of our knowledge, herein, a core-shell structure of B-NZVI featuring an Fe-B alloy shell beneath the iron oxide shell is demonstrated for the first time. Alloyed boron can reduce H+, contributing to more than 35.6% of H2 generation during acid digestion of B-NZVIs. In addition, alloyed B provides electrons for Fe3+ reduction during Cr(VI) removal, preventing in situ passivation of the reactive particle surface. Meanwhile, the amorphous oxide shell of B-NZVI exhibits an increased defect density, promoting the release of Fe2+ outside the shell to reduce Cr(VI), forming layer-structured precipitates and intense Fe-O bonds. Consequently, the surface-area-normalized capacity and surface reaction rate of B-NZVI are 6.5 and 6.9 times higher than those of crystalline NZVI, respectively. This study reveals the importance of alloyed B in Cr(VI) removal using B-NZVI and presents a comprehensive approach for investigating electron pathways and mechanisms involved in B-NZVIs for contaminant removal.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    低镇痛效率限制了镁在镇痛中的使用。这里,我们报道了具有离子电流整流活性的氢化硼(BH)可以显着提高镁的镇痛效率,甚至比吗啡还高.合成的可注射MgB2由与Mg2+交替的六方硼片组成。在病理环境中,而插层的Mg2+将被H+交换,将形成2维硼苯类似物BH片,以通过阳离子-pi相互作用与带电阳离子相互作用,协同导致神经元中钠离子和钾离子电流的一种双向动态调制。通过与释放的Mg2+协调来竞争Ca2+,阈值电位从正常的-35.9mV显著增加到-5.9mV,显著抑制神经元兴奋性,提供有效的镇痛作用。在三种典型的疼痛模型中,包括CFA引起的炎性疼痛,PINP或CCI引起的神经性疼痛,MgB2显示其镇痛效率分别比临床MgSO4高约2.23、3.20和2.0倍。MgB2作为镇痛药物的开发解决了疼痛缓解的未满足的医疗需求,而没有药物耐受性或对阿片类药物成瘾的风险。
    The limited analgesic efficiency of magnesium restricts its application in pain management. Here, we report boron hydride (BH) with ion currents rectification activity that can enhance the analgesic efficiency of magnesium without the risks of drug tolerance or addiction. We synthesize MgB2, comprising hexagonal boron sheets alternating with Mg2+. In pathological environment, Mg2+ is exchanged by H+, forming two-dimensional borophene-analogue BH sheets. BH interacts with the charged cations via cation-pi interaction, leading to dynamic modulation of sodium and potassium ion currents around neurons. Additionally, released Mg2+ competes Ca2+ to inhibit its influx and neuronal excitation. In vitro cultured dorsal root neurons show a remarkable increase in threshold potential from the normal -35.9 mV to -5.9 mV after the addition of MgB2, indicating potent analgesic effect. In three typical pain models, including CFA-induced inflammatory pain, CINP- or CCI-induced neuropathic pain, MgB2 exhibits analgesic efficiency approximately 2.23, 3.20, and 2.0 times higher than clinical MgSO4, respectively, and even about 1.04, 1.66, and 1.95 times higher than morphine, respectively. The development of magnesium based intermetallic compounds holds promise in addressing the non-opioid medical need for pain relief.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    具有独特形态和改进的储氢性能的纳米结构金属氢化物引起了人们的强烈兴趣。然而,研究高活性硼氢化物的生长过程仍然具有挑战性。在这里,首次报道了通过氢辅助一锅溶剂热反应合成LiBH4纳米棒。正丁基锂与三乙胺硼烷在正己烷中在50巴的H2下在40-100°C下反应,形成了直径为500-800nm的[100]取向的LiBH4纳米棒,其生长是由定向附着和配体吸附驱动的。独特的形态使LiBH4纳米棒能够从≈184°C释放氢,比商业样品低94°C(≈278°C)。在450°C下40分钟内氢释放量为13wt%,具有稳定的循环能力,显著优于商业LiBH4(≈9.1重量%)。更重要的是,相对于商业对应物,通过纳米棒样品成功地实现了氢化起始温度的高达180°C的降低。LiBH4纳米棒在脱氢过程中没有起泡,提高了氢气循环性能。新方法将揭示纳米结构金属硼氢化物作为高级功能材料的制备。
    Nanostructured metal hydrides with unique morphology and improved hydrogen storage properties have attracted intense interests. However, the study of the growth process of highly active borohydrides remains challenging. Herein, for the first time the synthesis of LiBH4 nanorods through a hydrogen-assisted one-pot solvothermal reaction is reported. Reaction of n-butyl lithium with triethylamine borane in n-hexane under 50 bar of H2 at 40-100 °C gives rise to the formation of the [100]-oriented LiBH4 nanorods with 500-800 nm in diameter, whose growth is driven by orientated attachment and ligand adsorption. The unique morphology enables the LiBH4 nanorods to release hydrogen from ≈184 °C, 94 °C lower than the commercial sample (≈278 °C). Hydrogen release amounts to 13 wt% within 40 min at 450 °C with a stable cyclability, remarkably superior to the commercial LiBH4 (≈9.1 wt%). More importantly, up to 180 °C reduction in the onset temperature of hydrogenation is successfully attained by the nanorod sample with respect to the commercial counterpart. The LiBH4 nanorods show no foaming during dehydrogenation, which improves the hydrogen cycling performance. The new approach will shed light on the preparation of nanostructured metal borohydrides as advanced functional materials.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    农作物农药残留的环境监测对于食品安全和环境保护都至关重要。传统的方法面临的挑战,由于在果皮和牙髓组织内源性化合物的干扰,通常是侵入性的,劳动密集型,不足以实时观察有害物质的分布。在这项研究中,动态硼氢化物还原的纳米粒子被用作增强的底物。第一次,利用表面增强拉曼光谱(SERS)成像来实现农药残留的全过程视觉检测。所开发的方法既稳定又灵敏,检测下限低于1pg/mL,再加上强大的定量分析能力。该技术已成功用于检测各种作物和果汁中的残留信号。此外,SERS成像用于绘制从水果和蔬菜外部到内部的农药残留分布图。顶点成分分析通过减轻植物自发荧光的干扰进一步完善了该过程。总的来说,这一创新战略促进了全面的农药残留监测,为控制农作物中的有害物质提供了有力的工具。它的潜在应用范围超出了食品安全,对可持续农业生产和加强环境保护抱有重大希望。
    Environmental monitoring of pesticide residues in crops is essential for both food safety and environmental protection. Traditional methodologies face challenges due to the interference of endogenous compounds in peel and pulp tissues, often being invasive, labor-intensive, and inadequate for real-time observation of hazardous substance distribution. In this study, dynamic borohydride-reduced nanoparticles were employed as enhanced substrates. For the first time, surface-enhanced Raman spectroscopy (SERS) imaging was harnessed to enable whole-process visual detection of pesticide residues. The developed method is both stable and sensitive, boasting a detection lower limit below 1 pg/mL, coupled with robust quantitative analytical capabilities. This technique was successfully employed to detect residue signals across various crops and fruit juices. Furthermore, SERS imaging was utilized to map the distribution of pesticide residues from the exterior to the interior of fruits and vegetables. Vertex component analysis further refined the process by mitigating interference from plant autofluorescence. Collectively, this innovative strategy facilitates comprehensive pesticide residue monitoring, offering a potent tool for controlling hazardous substances in crops. Its potential applications extend beyond food safety, holding significant promise for sustainable agricultural production and enhanced environmental safeguarding.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    提出了一种创造性地设计的新型两步增强技术,其中B族维生素分子被硼氢化钠动态吸附到银纳米颗粒的表面上,随后在阳离子(钙离子)存在下进行局部等离子体共振,最终在同一分子上实现化学和物理协同增强,并构建维生素检测的“表面热点”两步增强平台。促进的维生素分子的拉曼信号增强了9个数量级。在随后的研究中,观察到维生素B2分子在银纳米颗粒的表面上处于接近垂直的图像中,这也可能有助于拉曼信号增强。结合深度学习技术,该方法已成功应用于体液中B族维生素的检测。作为一个准确的,快速,可重复,非侵入性,和多功能测定平台,它为智能识别食品中的痕量B分子带来了巨大的希望,制药,和人体。
    A creatively designed novel two-step enhancement technique is presented in which B vitamin molecules are dynamically adsorbed onto the surface of silver nanoparticles by sodium borohydride, followed by local plasmon resonance in the presence of cations (calcium ions), ultimately achieving synergistic chemical and physical enhancement on the same molecule and constructing a \"surface hot spots\" two-step enhancement platform for vitamin detection. The Raman signal of the promoted vitamin molecule is enhanced by nine orders of magnitude. In a subsequent study it was observed that the vitamin B2 molecules were in a near-vertical image on the surface of the silver nanoparticles, which may also contribute to the Raman signal enhancement. Combined with deep learning techniques, the method has been successfully applied to the detection of B vitamins in body fluids. As an accurate, rapid, reproducible, non-invasive, and versatile assay platform, it holds great promise for the intelligent identification of trace B molecules in food, pharmaceuticals, and the human body.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    石榴石型氧化物Li6.4La3Zr1.4Ta0.6O12(LLZTO)具有优异的离子导电性和对锂(Li)金属的良好稳定性,但是需要高温烧结(约1200°C),这会导致高制造成本,机械加工性差,和高界面电阻。这里,报道了一种包含LLZTO-4LiBH4/xLi3BN2H8的新型高性能三组分复合固体电解质(CSE),它是通过球磨LLZTO-4LiBH4混合物,然后用Li3BN2H8手工研磨制备的。通过在120°C下加热冷压CSE粉末制成的绿色颗粒可提供超快的室温离子电导率(在30°C下约为1.73×10-3Scm-1)和超高的锂离子迁移数(约0.9999),这使得Li|Li对称电池在30°C下以仅30mV的过电位循环超过1600h。此外,Li|CSE|TiS2全电池提供201mAhg-1的容量,具有长循环能力。这些出色的性能是由于电解质颗粒中的低开孔率以及Li3BN2H8的高固有离子电导率和易变形性。
    Garnet-type oxide Li6.4 La3 Zr1.4 Ta0.6 O12 (LLZTO) features superior ionic conductivity and good stability toward lithium (Li) metal, but requires high-temperature sintering (≈1200 °C) that induces high fabrication cost, poor mechanical processability, and high interface resistance. Here, a novel high-performance tricomponent composite solid electrolyte (CSE) comprising LLZTO-4LiBH4 /xLi3 BN2 H8 is reported, which is prepared by ball milling the LLZTO-4LiBH4  mixture followed by hand milling with Li3 BN2 H8 . Green pellets fabricated by heating the cold-pressed CSE powders at 120 °C offer ultrafast room-temperature ionic conductivity (≈1.73 × 10-3  S cm-1  at 30 °C) and ultrahigh Li-ion transference number (≈0.9999), which enable the Li|Li symmetrical cells to cycle over 1600 h at 30 °C with only 30 mV of overpotential. Moreover, the Li|CSE|TiS2  full cells deliver 201 mAh g-1  of capacity with long cyclability. These outstanding performances are due to the low open porosity in the electrolyte pellets as well as the high intrinsic ionic conductivity and easy deformability of Li3 BN2 H8 .
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    原子精确的第11族金属团簇(Cu,Ag,和Au)由于其出色的结构和引人入胜的特性而引起了极大的关注。这些簇的独特亚类之一基于[(RO)2PE2]型的二磷酸盐配体(E=S或Se,和R=烷基)。这些配体成功地稳定了最多样化的Cu,Ag,Au团簇和超原子,从简单的到惊人的组件,具有不寻常的结构和粘合模式。值得注意的是,这种复杂的簇是由廉价和简单的试剂直接组装而成的,金属(I)盐和二磷酸根阴离子。这个反应,当在氢化物或其他阴离子源存在下进行时,或者外来金属离子,导致氢化物或阴离子模板的均核或异核结构。在这篇专题文章中,我们调查了这个令人兴奋的领域的最新进展,突出了“金属(I)盐-[(RO)2PX2]-配体-模板阴离子或硼氢化物”系统的强大合成能力,作为创建新的原子精确簇的取之不尽的平台,超原子,和纳米合金。
    Atomically precise clusters of group 11 metals (Cu, Ag, and Au) attract considerable attention owing to their remarkable structure and fascinating properties. One of the unique subclasses of these clusters is based on dichalcophosphate ligands of [(RO)2PE2]- type (E = S or Se, and R = alkyl). These ligands successfully stabilise the most diverse Cu, Ag, and Au clusters and superatoms, spanning from simple ones to amazing assemblies featuring unusual structural and bonding patterns. It is noteworthy that such complicated clusters are assembled directly from cheap and simple reagents, metal(I) salts and dichalcophosphate anions. This reaction, when performed in the presence of a hydride or other anion sources, or foreign metal ions, results in hydrido- or anion-templated homo- or heteronuclear structures. In this feature article, we survey the recent advances in this exciting field, highlighting the powerful synthetic capabilities of the system \"a metal(I) salt - [(RO)2PX2]- ligands - a templating anion or borohydride\" as an inexhaustible platform for the creation of new atomically precise clusters, superatoms, and nanoalloys.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    当前固体电解质和高容量阳极之间的低离子和电子电导率限制了全固态锂离子电池(ASSLIB)的长期循环性能。在这里,这项工作报告了用于高性能ASSLIB的超稳定电极-固体电解质复合材料的制造,该复合材料通过在每个均匀分布在石墨烯上的MgH2纳米颗粒的表面上均匀覆盖超薄Mg(BH4)2层而实现。Mg(BH4)2层的初始放电过程导致MgH2纳米颗粒的均匀覆盖,其中LiBH4作为固体电解质,Li2B6具有比LiBH4更高的Li离子电导率。因此,覆盖有超薄Mg(BH4)2层的石墨烯负载的MgH2纳米颗粒的Li离子电导率比没有Mg(BH4)2层的Li离子电导率高两个数量级。此外,由此形成的对LiBH4具有强吸附能力的惰性Li2B6,作为一个稳定的框架,which,再加上石墨烯的结构支撑作用,减轻MgH2纳米颗粒的体积变化,促进LiBH4和单个MgH2纳米颗粒之间的密切接触,导致在每个MgH2纳米颗粒上形成具有高离子和电子电导率的均匀稳定界面。因此,在350次循环后,MgH2在2Ag-1下实现了800mAhg-1的超高比容量。
    The low ionic and electronic conductivity between current solid electrolytes and high-capacity anodes limits the long-term cycling performance of all-solid-state lithium-ion batteries (ASSLIBs). Herein, this work reports the fabrication of an ultra-stable electrode-solid electrolyte composite for high-performance ASSLIBs enabled by the homogeneous coverage of ultrathin Mg(BH4 )2 layers on the surface of each MgH2 nanoparticle that are uniformly distributed on graphene. The initial discharge process of Mg(BH4 )2 layers results in uniform coverage of MgH2 nanoparticle with both LiBH4 as the solid electrolyte and Li2 B6 with even higher Li ion conductivity than LiBH4 . Consequently, the Li ion conductivity of graphene-supported MgH2 nanoparticles covered with ultrathin Mg(BH4 )2 layers is two orders of magnitude higher than that without Mg(BH4 )2 layers. Moreover, the thus-formed inactive Li2 B6 with strong adsorption capability toward LiBH4 , acts as a stabilizing framework, which, coupled with the structural support role of graphene, alleviates the volume change of MgH2 nanoparticles and facilitates the intimate contact between LiBH4 and individual MgH2 nanoparticles, leading to the formation of uniform stable interfaces with high ionic and electronic conductivity on each MgH2 nanoparticles. Hence, an ultrahigh specific capacity of 800 mAh g-1 is achieved for MgH2 at 2 A g-1 after 350 cycles.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    果糖-1,6-二磷酸醛缩酶(EC4.1.2.13)是一种高度保守的酶,参与糖酵解和糖异生。在这项研究中,我们从Euphausiasuperba(EsFBA)中克隆了果糖-1,6-二磷酸醛缩酶基因。EsFBA的全长cDNA序列长1098bp,编码365个氨基酸的蛋白质。果糖-1,6-二磷酸醛缩酶基因在大肠杆菌中表达(E。大肠杆菌)。使用HisTrapHP亲和色谱和尺寸排阻色谱获得高度纯化的蛋白质。预测的EsFBA三维结构与人醛缩酶有65.66%的同源性,与南美白对虾FBA的同源性最高(84.38%)。重组EsFBA在45°C和pH7.0的磷酸盐缓冲液中具有最高的活性。通过检测金属离子和EDTA的活性,发现金属离子和EDTA对EsFBA酶活性的影响不显著,而硼氢化物的存在严重降低了酶活性;因此,EsFBA被确认为I类醛缩酶。此外,在位置34、147、188和230的靶向突变证实它们是EsFBA的关键氨基酸残基。
    Fructose-1,6-bisphosphate aldolase (EC 4.1.2.13) is a highly conserved enzyme that is involved in glycolysis and gluconeogenesis. In this study, we cloned the fructose-1,6-bisphosphate aldolase gene from Euphausia superba (EsFBA). The full-length cDNA sequence of EsFBA is 1098 bp long and encodes a 365-amino-acid protein. The fructose-1,6-bisphosphate aldolase gene was expressed in Escherichia coli (E. coli). A highly purified protein was obtained using HisTrap HP affinity chromatography and size-exclusion chromatography. The predicted three-dimensional structure of EsFBA showed a 65.66% homology with human aldolase, whereas it had the highest homology (84.38%) with the FBA of Penaeus vannamei. Recombinant EsFBA had the highest activity at 45 °C and pH 7.0 in phosphate buffer. By examining the activity of metal ions and EDTA, we found that the effect of metal ions and EDTA on EsFBA\'s enzyme activity was not significant, while the presence of borohydride severely reduced the enzymatic activity; thus, EsFBA was confirmed to be a class I aldolase. Furthermore, targeted mutations at positions 34, 147, 188, and 230 confirmed that they are key amino acid residues for EsFBA.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    热固性不饱和聚酯树脂(UPR)复合材料被发现广泛的工业应用。然而,交联网络中众多稳定的碳-碳键使它们难以降解,造成大规模的复合废物。在这里,利用纳米级Fe0催化剂原位形成策略,通过类Fenton反应从UPR复合材料中无损回收碳纤维(CF)。该策略中使用的纳米Fe0催化剂活化H2O2以去除UPR,具有温和的条件和高效的降解能力。针对催化剂的容易生长,通过碱体系的水解实现了多孔UPR。随后通过硼氢化物还原在水解树脂的表面上原位形成纳米级Fe0催化剂。受益于快速传质,在类Fenton反应过程中,原位生长的纳米Fe0比添加的纳米Fe0或Fe2催化剂显示出更有效的降解能力。实验表明,水解树脂可以在80min内降解90%以上,80°CGC-MS,通过FT-IR分析和密度泛函理论(DFT)计算来解释水解树脂中碳骨架的断裂过程。尤其是,从复合材料中观察到CF的显着恢复过程,100%消除树脂。回收的CF布表现出99%的强度保留和保持纺织结构,微观形貌,化学结构,导致CF的无损回收。这种原位形成的纳米级Fe0催化降解策略可以为从UPR复合材料中无损回收CF提供有前途的实际应用。
    Thermosetting unsaturated polyester resin (UPR) composites were found widespread industrial applications. However, the numerous stable carbon-carbon bonds in cross-linked networks made them intractable for degradation, causing the large-scale composite wastes. Here a nanoscale Fe0 catalyst in-situ forming strategy was exploited to nondestructively recycle carbon fiber (CF) from UPR composites via Fenton-like reaction. The nano-Fe0 catalyst employed in this strategy activated H2O2 for removing UPR, featuring mild conditions and efficient degradation ability. Aiming at facile growth of the catalyst, a porous UPR was achieved by the hydrolysis of alkalic system. The nanoscale Fe0 catalyst was subsequently formed in-situ on the surface of hydrolyzed resin by borohydride reduction. Benefiting from fast mass transfer, the in-situ grown nano-Fe0 showed more efficient degradation ability than added nano-Fe0 or Fe2+ catalyst during Fenton-like reaction. The experiments indicated that hydrolyzed resin could be degraded more than 90% within 80 min, 80 °C. GC-MS, FT-IR analysis and Density functional theory (DFT) calculation were conducted to explained the fracture processes of carbon skeleton in hydrolyzed resin. Especially, a remarkable recovery process of CF from composites was observed, with a 100 percent elimination of resin. The recycled CF cloth exhibited a 99% strength retention and maintained the textile structure, microtopography, chemical structure, resulting in the nondestructive reclaim of CF. This in-situ formed nanoscale Fe0 catalytic degradation strategy may provide a promising practical application for nondestructively recycle CF from UPR composites.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号