High specific capacity, availability of tin oxide (SnO2) and improved electrical conductivity and rate capability of boron-doped graphene sheets (BG) promises the composite of the two as a potential ...anode material for Li ion battery. We report for the first time, one-pot synthesis of SnO2 dispersed boron-doped few layer graphene (SnO2/BG-I) in an environment friendly, hazardous-harmful reducing agent free, hydrogen assisted reduction technique in comparison to complicated two-step conventional process. In addition, a two-step, wet chemical free, greener approach is also employed to achieve SnO2 nanoparticles over BG support (SnO2/BG-II). Both the materials as anode showed enhanced performance compared to un-doped graphene supported SnO2 nanoparticles (SnO2/G). One-pot synthesized SnO2/BG-I as anode in Li ion battery shows comparable performance with a reversible capacity of 348 mAh g−1 at a current density 200 mA g−1, while SnO2/BG-II with higher amount of boron doping, exhibits higher stability over cycles with an excellent reversible capacity of 558 mAh g−1 due to the uniform distribution of SnO2 over boron-doped graphene sheets.
Synthesized in novel and environment friendly methods, SnO2 dispersed boron-doped graphene exhibits enhanced anodic performance, owing to the synergistic effects of boron doping. Display omitted
Tris(perfluorotolyl)borane—A Boron Lewis Superacid Körte, Leif A.; Schwabedissen, Jan; Soffner, Marcel ...
Angewandte Chemie International Edition,
July 10, 2017, Volume:
56, Issue:
29
Journal Article
Peer reviewed
Open access
Tristetrafluoro‐4‐(trifluoromethyl)phenylborane (BTolF) was prepared by treating boron tribromide with tetrameric F3CC6F4‐CuI. The F3CC6F4‐CuI was generated from F3CC6F4MgBr and copper(I) bromide. ...Lewis acidities of BTolF evaluated by the Gutmann–Beckett method and calculated fluoride‐ion affinities are 9 and 10 %, respectively, higher than that of tris(pentafluorophenyl)borane (BCF) and even higher than that of SbF5. The molecular structures of BTolF and BCF were determined by gas‐phase electron diffraction, that of BTolF also by single‐crystal X‐ray diffraction.
Superacidic tristetrafluoro‐4‐(trifluoromethyl)phenylborane (BTolF) was prepared from BBr3 and F3CC6F4‐CuI. It is a stronger Lewis acid than tris(pentafluorophenyl)borane (BCF) and has a higher fluoride‐ion affinity than SbF5. The structures of BTolF and of the widely used BCF were determined by gas‐phase electron diffraction and reflect the different electronic situations.
Boron-hydrides are the most promising source to produce clean H2 gas with very high rate at room temperature. To increase and control the H2 generation rate through hydrolysis of boron-hydrides an ...efficient and robust catalyst is necessary, made up of elements that are abundant in our earth. Interest in Co-based catalysts, mainly cobalt boride (Co–B), arises by their special features that make them potential substitute of noble metal catalyst for H2 production. Even economically this catalyst best suits the scenario for the future systems. The present review exhaustively and systematically highlights the progress made in the development of Co-based catalyst towards hydrogen production by hydrolysis of various boron-hydrides. Various strategies for synthesizing such catalysts and improving their activity and stability, including optimizing preparation conditions, nanostructuring, alloying, supporting on various materials, and exploiting hybrid systems, are discussed. Finally, by summarizing the successful and efficient routes, future challenges and perspectives to design a novel single catalyst for direct application are presented, along with the problems that must be resolved on a theoretical level to understand the mechanisms that govern the process of catalysis: this is an area of research that usually affects all catalysts.
•Review on Co–B catalyst for H2 production by hydrolysis of Boron-hydrides.•Nano-structured Co–B catalyst can be a possible replacement for noble metal.•Strategies to enhance the activity and stability of Co–B are exhaustively reviewed.•Future challenges and perspectives to design a novel single catalyst are presented.
Deprotonation of (cAAC)BH2(CN) provided clean access to the stable boryl anion, (cAAC)BH(CN)−. Whereas the addition of soft electrophiles occurred at the nucleophilic boron center, harder silyl ...electrophiles added to the harder terminal cyano nitrogen. The resulting (cAAC)BH(CNSiPh3) species behaved like a silylium boryl nucleophile as well as a neutral silylisonitrile borylene.
Whereas the salt metathesis of soft electrophiles with the (cyano)hydroboryl anion (cAAC)B(CN)H− occurs at the nucleophilic boron center, comparatively harder silyl electrophiles add to the harder terminal cyano nitrogen. The resulting (cAAC)BH(CNSiR3) species behave as both zwitterionic silylium boryl and neutral silylisonitrile borylene, a BI compound accessed through simple deprotonation and salt metathesis. cAAC=cyclic (alkyl)(amino)carbene.
Great interest in anode materials has dramatically emerged with increasing demand for electrochemically generated oxidants in industrial electrochemistry. For the last five decades, these needs have ...been mostly achieved by the introduction of two well-known anode materials, the dimensional stable anode (DSA®) and boron-doped diamond (BDD) electrodes. Nevertheless, the high cost and complicated process in fabricating these electrodes remains as a big obstacle for further development. Here, we report a novel anode material for the production of oxidants, the dark blue colored TiO2 nanotube array (NTA) (denoted as Blue TiO2 NTA) which has never been successfully achieved with titania-based materials. This titania-based electrocatalyst with irreversible electrochromism and high conductivity was successfully fabricated with simple cathodic polarization of anatase TiO2 NTA and exhibits the excellent electrocatalytic activity in generating chlorine (Cl2) and hydroxyl radical (•OH) which is comparable to the commercial DSA® and BDD electrodes, respectively. Thus, this Blue TiO2 NTA is suggested as a potential cost effective anodic material in industrial electrochemistry. In addition, even in other metal oxides other than titania, the cathodic polarization (accompanied with irreversible electrochromism) method may be applied to explore a new route for low-cost and novel anodic materials.
An ionic covalent–organic framework (ICOF-1 containing sp3 hybridized boron anionic centers formed by spiroborate linkage and dimethylammonium ions) is explored as an ion exchanger for the removal of ...lead (Pb2+) ions from aqueous solution. From molecular simulations, the Pb2+ ions are observed to exchange with the nonframework DMA+ ions in the ICOF-1. At a concentration of 600 ppm, the Pb2+ ions are completely exchanged and reside in the ICOF-1, while the DMA+ ions are in a dynamic equilibrium with the solution. It is revealed that the exchange between Pb2+ and DMA+ is governed by the stronger attraction of Pb2+ with the negatively charged ICOF-1 framework. The radial distribution functions and mean-squared displacements further show that the exchanged Pb2+ ions are in a closer proximity to the ICOF-1 framework with a smaller mobility than DMA+ ions. The simulation study provides microscopic insight into the ion-exchange process between Pb2+ and DMA+, and it suggests that the ICOF-1 might be an intriguing candidate for water purification.
This paper describes the origin of the reactivity and stability of boron-modified copper-based catalysts with prolonged lifespan for the vapor-phase selective hydrogenation of dimethyl oxalate to ...ethanol. Display omitted
► A low-cost copper-based catalyst for synthesis of ethanol with high efficiency. ► Boron modification is a readily available approach for improving the stability. ► Boron could improve the copper dispersion and suppress the growth of Cu particles. ► Boron affects the acidic/basic sites and enhances the metal–support interaction.
The long-term stability and activity of catalysts are vital for vapor-phase selective hydrogenation of dimethyl oxalate to synthesize ethanol. Boron has been widely employed as a modifier for transition-metal catalysts mainly to, improve selectivity and stability. We introduced boron species by impregnation into silica-supported copper catalysts prepared by an ammonia evaporation hydrothermal method and investigated their catalytic activity and thermal stability for hydrogenation of dimethyl oxalate. The effect on activity mainly depends on the amount of boron and an optimal Cu/B molar ratio of 3 was obtained. The characterization of the catalysts shows that boron-modified Cu/SiO2 facilitates the dispersion of copper species, enhances the metal–support interaction, and suppresses the growth of copper particles during dimethyl oxalate hydrogenation.
High‐grade periodate is relatively expensive, but is required for many sensitive applications such as the synthesis of active pharmaceutical ingredients. These high costs originate from using lead ...dioxide anodes in contemporary electrochemical methods and from expensive starting materials. A direct and cost‐efficient electrochemical synthesis of periodate from iodide, which is less costly and relies on a readily available starting material, is reported. The oxidation is conducted at boron‐doped diamond anodes, which are durable, metal‐free, and nontoxic. The avoidance of lead dioxide ultimately lowers the cost of purification and quality assurance. The electrolytic process was optimized by statistical methods and was scaled up in an electrolysis flow cell that enhanced the space–time yields by a cyclization protocol. An LC‐PDA analytical protocol was established enabling simple quantification of iodide, iodate, and periodate simultaneously with remarkable precision.
The electrochemical synthesis of periodate from iodide at boron‐doped diamond (BDD) anodes was developed, which in contrast to lead dioxide anodes are sustainable and durable. Toxic contaminations are hereby prevented, ultimately reducing the cost of purification. This opens the door for the broad application of periodate for demanding applications, such as the synthesis of active pharmaceutical ingredients.
Incorporation of electron deficient boron atoms along with Au doped TiO2 in the presence of rGO support was synthesized by hydrothermal method and demonstrated for the sonophotocatalytic degradation ...of TC under visible light illumination. The successful incorporation of electron deficient boron atoms and Au on TiO2 was considerably enhanced the optical absorption towards visible region due to the formation acceptor energy levels below to the conduction band of TiO2 by boron doping and surface plasmonic effect of Au. Moreover, formation of acceptor energy levels and introduction of reduced graphene oxide (rGO) support significantly improved the electron–hole pair separation and transportation which were supported by UV–vis-DRS, photo-current and photoluminescence measurements. The individual effect of photocatalysis and ultrasound for the TC degradation was found to be 45% and 12%, respectively. Importantly, a complete degradation (100%) of TC was achieved with 1.3 folds synergistic effect when ultrasound coupled with photocatalysis in 1 h. The enhanced degradation activity was mainly attributed to combined effect of rapid electron-hole pair separation facilitated by electron deficient B-atoms and rGO support and physical forces of ultrasound as well. In addition, ∼74% of Total Organic Carbon (TOC) removal was achieved within 1 h which further confirmed the effective demineralization of TC by the Au/B-TiO2/rGO composite.
The enormous demand for medical diagnostics has encouraged the fabrication of high- performance sensing platforms for the detection of glucose. Nonenzymatic glucose sensors are coming ever closer to ...being used in practical applications. Bimetallic catalysts have been shown to be superior to single metal catalysts in that they have greater activity and selectivity. Here, we demonstrate the preparation, characterization, and electrocatalytic characteristics of a new bimetallic Pt/Au nanocatalyst. This nanocatalyst can easily be synthesized by electrodeposition by sequentially depositing Au and Pt on the surface of a boron-doped diamond (BDD) electrode. We characterized the nanocatalyst by scanning electron microscopy (SEM), X-ray diffraction (XRD), and voltammetry. The morphology and composition of the nanocatalyst can be easily controlled by adjusting the electrodeposition process and the molar ratio between the Pt and Au precursors. The electrocatalytic characteristics of a Pt/Au/BDD electrode for the nonenzymatic oxidation of glucose were systematically investigated by cyclic voltammetry. The electrode exhibits higher catalytic activity for glucose oxidation than Pt/BDD and Au/BDD electrodes. The best catalytic activity and stability was obtained with a Pt:Au molar ratio of 50:50. Moreover, the presence of Au can significantly enhance the long-term stability and poisoning tolerance during the electro-oxidation of glucose. Measurements of glucose using the Pt/Au/BDD electrode were linear in the range from 0.01 to 7.5mM, with a detection limit of 0.0077mM glucose. The proposed electrode performs selective electrochemical analysis of glucose in the presence of common interfering species (e.g., acetaminophen, uric and ascorbic acids), avoiding the generation of overlapping signals from such species.
•Non-enzymatic glucose sensor of BDD electrodes with Pt/Au nanocatalyst was designed.•Significant improvements in the response to glucose in neutral media were obtained.•Excellent stability, selectivity and reproducibility were confirmed.
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