Boron Source Research Articles

Oxygenated boron-doped carbon via polymer dehalogenation as an electrocatalyst for high-efficiency O2 reduction to H2O2

The direct electrochemical synthesis of H2O2 from O2 is currently the most promising alternative to energy-intensive industrial anthraquinone oxidation/reduction methods. However, its widespread use is hampered by the lack of efficient low-cost electrocatalysts. In the current study, oxygenated boron-doped carbon (O-BC) materials were realized via a green synthetic strategy involving polymer dehalogenation and employed as electrode materials for the electrochemical synthesis of H2O2via a 2e− oxygen reduction. The catalytic activity of the O-BC materials was optimized through systematic variation of the boron source (H3BO3) dosage and annealing temperature. Electrochemical measurements revealed that the optimal sample (O-BC-2-650) exhibited a selectivity of 98% for the 2e− oxygen reduction to H2O2 and an average H2O2 production rate of 412.8 mmol gcat−1 h−1 in an H-type alkaline electrolyzer. Density functional theory simulations indicated that the functionalization of active B sites with one oxygen atom provides the lowest Gibbs free energy change (ΔG) of 0.03 eV for the hydrogenation of *O2, while functionalization with zero or two O atoms results in much larger ΔG values (0.08 and 0.10 eV, respectively). Thus, this work details a new type of green, low-cost, and metal-free electrocatalyst for H2O2 production.

A simple synthesis of surfactant-free polycrystalline CuO nanoparticles supported on carbon nanofibers for regioselective hydroboration of alkynes.

Copper oxide nanoparticles (CuO NPs) with a clean surface supported on carbon nanofibers (CNFs) in one-pot were prepared by simple solid-state grinding and aging followed by thermal treatment, yielding CuO nanoparticles with high (23.8 wt%) and uniform CuO loading in the absence of surfactants and solvent. The CuO NPs on CNFs (CuO/CNF) showed excellent catalytic activity in transforming a wide variety of alkynes into alkenyl boronates using B2Pin2 as a boron source in the absence of ligand and additives with high regioselectivity under mild conditions. Moreover, the present CuO/CNF catalyst was recyclable and possesses excellent chemoselectivity. The developed green synthetic approach is expected to offer exciting opportunities for designing monometallic or bimetallic nanoparticle catalysts on different supports applied in heterogeneous catalysis.

Visible-light-driven PhSSPh-catalysed regioselective hydroborylation of α,β-unsaturated carbonyl compounds with NHC-boranes.

A photo-induced transition-metal-free regioselective hydroborylation of α,β-unsaturated carbonyl compounds is developed. The PhSSPh reagent was employed as the photocatalyst, and NHC-BH3 was used as the boron source. This transformation shows a broad substrate scope and provides a wide range of α-borylcarbonyl molecules in good to excellent yields.

Boron doped fluorescent carbon nano dots for the reduction of ionic dyes and as encryption/decryption QR security code labels

This work discusses the synthesis of fluorescent undoped and boron-doped carbon nanodots (BDCNDs) by a simple hydrothermal approach usingTribulus terrestrisas the carbon precursor and boric acid as the boron source.

Realizing outstanding electrochemical performance with Na3V2(PO4)2F3 modified with an ionic liquid for sodium-ion batteries.

Na3V2(PO4)2F3 is a typical NASICON structure with a high voltage plateau and capacity. Nevertheless, its applications are limited due to its low conductivity and poor rate performance. In this study, nitrogen–boron co-doped carbon-coated Na3V2(PO4)2F3 (NVPF-CNB) was prepared by a simple sol–gel method using an ionic liquid (1-vinyl-3-methyl imidazole tetrafluoroborate) as a source of nitrogen and boron for the first time. The morphology and electrochemical properties of NVPF-CNB composites were investigated. The results show that a nitrogen–boron co-doped carbon layer could increase the electron and ion diffusion rate, reduce internal resistance, and help alleviate particle agglomeration. NVPF-CNB-30 exhibited better rate performance under 5C and 10C charge/discharge with initial reversible capacities of 99 and 90 mA h g−1, respectively. Furthermore, NVPF-CNB-30 illustrates excellent cyclic performance with the capacity retention rate reaching 91.9% after 500 cycles at 5C, as well as a capacity retention rate of about 95.5% after 730 cycles at 10C. The evolution of the material's structure during charge/discharge processes studied by in situ X-ray diffraction confirms the stable structure of nitrogen–boron co-doped carbon-coated Na3V2(PO4)2F3. Co-doping of nitrogen and boron also provides more active sites on the surface of Na3V2(PO4)2F3, revealing a new strategy for the modification of sodium-ion batteries.

Simultaneous microwave-assisted reduction and B/N co-doping of graphene oxide for selective recognition of VOCs

The influence of heteroatom domains on the volatile organic compound (VOC) detection properties of B/N co-doped graphene oxide nanostructures is investigated by using different boron (B) and nitrogen (N) sources.

Preparation of boron doped diamond-like carbon films in a low-pressure high-density plasma in RF ICP-CVD

The main objective of this work is to prepare electrically conducting boron doped diamond-like carbon (DLC) films with good crystalline qualities and high optical band gap in a low pressure and high-density plasma in an RF ICP CVD system. The main precursor gas used was CH4, with Ar being the diluent gas. B2H6 in He was used as the main source of boron, as the dopant, in the system. Planar inductively coupled technique enables the plasma to be ignited at a very low deposition pressure of 30 mTorr. A substrate temperature of 450 °C, a 900 W of RF power and a dc substrate bias of −40 V were used during the sample growth. By varying the B2H6/CH4 (=R) ratio, the optimized condition for preparing boron doped DLC thin films was obtained at R = 1. Raman analysis showed that this sample has the minimum ID/IG ratio ∼0.83, a maximum IDia/ID (∼1.18) and a maximum IDia/IG (∼0.98). The sp3 C-C content of 48.05% was calculated from XPS. A high optical band gap of ∼3.8 eV was obtained from the UV–Vis spectra. Boron doping was confirmed from the Raman, XPS and electrical conductivity measurements.

THERAPEUTIC APPLICATION OF TANKAR (BORAX) ACCORDING TO UNANI SYSTEM OF MEDICINE: A REVIEW

Borax is a mineral origin drug belongs to traditional system of medicine. It is a color less, translucent monoclinic crystalline with irregular shape. Chemically it is composition of boric acid and sodium. Its important component is Boron. It is also called as Sodium biborate. Borax contains 11.3% boron. Turkey is the largest source of borax about 73% of world. Vegetables, Fruits and salts are the main source of boron. Borax is used as a medicine because of its various therapeutic purposes such as Antimicrobial, Anticancer, Osteogenesis, Genotoxic, Vermicidal, Hemostatic, Analgesic and Healing properties. The information about this drug was extracted from traditional, modern drugs and electronic resources. Borax naturally present in crude form known as “sohagroo or tinkala”. After purification sohagroo called as Tankar (borax) and used for multiple therapeutic purposes. Borax is pentahydrate with specific gravity 1.73 having wide range of actions in Unani System of Medicine (USM) such as Jali(Cleanser/Detergent), Dafe-taaffun ( Antiseptic), Hazim ( Digestive), qatil-e-Jaraseem (Insecticides), Akkal (Corrosive), Munaffis-e-balgham (Expectorant), Mudir-e-hydz (Emmenogogue), Mudir-e-bowl (Diuretic), Kasir-i-Riyah (Carminative) and Daf-esamoom (Antidot). Traditionally used orally in the treatment of acidity, amenorrhea, dysmenorrhea, menorrhagia, puerperal convulsions (PIH). Locally beneficial for ulcers, piles, cystitis, leucorrhea, gonorrhea, cervical erosion also treat skin disease such as ringworm, acne, Pityriasis and melasma. Borax has temperament hot and dry temperament.

The Chemical and B-Isotope Composition of Tourmaline from Intra-Granitic Pegmatites in the Las Chacras-Potrerillos Batholith, Argentina

ABSTRACT The Devonian Las Chacras-Potrerillos batholith comprises six nested monzonitic to granitic intrusions with metaluminous to weakly peraluminous composition and a Sr-Nd isotopic signature indicating a dominantly juvenile mantle-derived source. The chemically most evolved units in the southern batholith contain a large number of intra-granitic, pod-shaped tourmaline-bearing pegmatites. This study uses in situ chemical and boron isotopic analyses of tourmaline from nine of these pegmatites to discuss their relationship to the respective host intrusions and the implications of their B-isotope composition for the source and evolution of the magmas. The tourmalines reveal a diversity in element composition (e.g., FeO, MgO, TiO2, CaO, MnO, F) which distinguishes individual pegmatites from one another. However, all have a narrow δ11B range of –13.7 to –10.5‰ (n = 100) which indicates a relatively uniform magmatic system and similar temperature conditions during tourmaline crystallization. The average δ11B value of –11.7‰ is typical for S-type granites and is within the range reported for peraluminous granites, pegmatites, and metamorphic units of the Ordovician basement into which the Las Chacras-Potrerillos batholith intruded. The B-isotope evidence argues for a crustal boron source like that of the Ordovician basement, in contrast to the metaluminous to weakly peraluminous composition and juvenile initial Sr and Nd isotope ratios of the Las Chacras-Potrerillos batholith magmas. We propose that the boron was not derived from the magma source region but was incorporated from dehydration melting of clastic metasedimentary rocks higher up in the crustal column.

СКАРНОВО-БОРОСИЛИКАТНЫЕ МЕСТОРОЖДЕНИЯ-ГИГАНТЫ: ПРОИЗВОДНЫЕ ФЛЮИДНО-ГИДРОТЕРМАЛЬНОЙ ПЕРЕРАБОТКИ ФРАГМЕНТОВ АТОЛЛОВ В СУБДУКЦИОННОМ МЕЛАНЖЕ МЕЗОЗОЙСКИХ ОРОГЕННЫХ ПОЯСОВ АЗИИ

Geological observations coupled with geochemical, isotopic and thermobaric-geochemical research of danburite ores of skarn-borosilicate deposits unique in their reserves in the Sikhote-Alin (Dalnegorskoe) and in the Pamir (Ak-Arkhar) indicated lagoonal strata and evaporites in the form of atoll fragments within the Mesozoic subduction mélange as the most probable boron source, which preceded the skarn formation. At the Dalnegorskoe deposit, the fact that boron is mobilized by skarn-forming solutions from evaporite accumulations is directly confirmed by isotopically heavier composition of boron (δ11В = +17.7 ‰) corresponding to marine evaporites, and a typical enrichment of fluid in lithium.

THE AVAILABILITY STATUS OF BORON IN THE CULTIVATED SOIL OF NEPAL

Boron is available in nature in rocks and deposits and the availability is influenced by soil organic matter, soil pH, soil texture, and temperature and is taken up by plants in non-ionic form H3BO3 (boric acid) but this concentration account for only about 10% of total soil boron leading to boron deficiency. Also, boron toxicity may occur in low rainfall, extremely alkaline, and saline soils harming plants’ growth and development. Boron shortage and toxicity in plants have a fairly narrow range, and both are detrimental. Hence, it is needed to critically balance boron homeostasis in cropping soil. The concentration of boron in cultivated soil in different agroecological regions was found to be low to very low (1mg/kg of soil) in this review study, which was undertaken to familiarize the status of boron in Nepalese cultivated land. In separate micronutrient investigations, a few additional micronutrients were shown to be medium albeit, boron was found to be low even in the valley (>0.01ppm) including all three ecological regions. This shows boron deficiency is a universal problem in Nepal affecting 80-90% of agricultural soil. And this problem can be corrected by both foliar applications and by soil application of boron sources such as borate as per the recommended dose.

A tandem process for the synthesis of β-aminoboronic acids from aziridines with haloamine intermediates.

An unprecedented synthetic strategy is devised to generate β-aminoboronic acids from aziridines via a sequential process involving 1,2-iodoamine formation and radical borylation under light irradiation. A variety of aziridines including multiply substituted aziridines have been successfully employed as synthetic precursors, expanding their synthetic utility compared to previous methods. Mechanistic studies suggest that the boron source plays a unique role in the borylation step, and in the formation of haloamine intermediates.

A highly selective and sensitive "on-off" fluorescent probe for detecting cadmium ions and l-cysteine based on nitrogen and boron co-doped carbon quantum dots.

Cadmium ions (Cd2+) have caused relatively serious pollution, threatening human health and ecosystems. l-Cysteine (l-Cys) is an essential amino acid in living organisms and concentration of l-Cys is closely related to some human diseases. In this work, we first introduced 2-amino-3-hydroxypyridine and sodium borohydride as the nitrogen source and boron source to fabricate boron and nitrogen co-doped carbon quantum dots (N,B-CQDs) with high fluorescence quantum yield (21.2%), which were synthesized through a simple, low-consumption and pollution-free one-pot hydrothermal method. The obtained N,B-CQDs are able to detect Cd2+ rapidly and sensitively through fluorescence enhancement, which may be ascribed to chelation enhanced fluorescence that is induced by the formation of the N,B-CQDs/Cd2+ complex. Simultaneously, N,B-CQDs can be used to detect l-cysteine because significant fluorescence quenching was observed when l-Cys was added into the N,B-CQDs/Cd2+ system. In the two fluorescence “turn-on” and “turn-off” processes, this fluorescent probe obtained a good linear relationship over Cd2+ concentration ranging from 2.5 µM to 22.5 µM with a detection limit of 0.45 µM, while the concentration of l-cysteine showed a linear relationship in the range of 2.5–17.5 µM with a detection limit of 0.28 µM. The sensor has been successfully used to detect Cd2+ and l-cysteine in real samples with satisfying results.

Triethylborane as Single Boron and Carbon Source Toward Stable and Homogeneous Boron‐Doped Graphene

Herein, the synthesis of a stable and homogeneous boron‐doped graphene film using triethylborane as a single source of carbon and boron is reported. The effects of triethylborane amount and growth time on the synthesis of doped graphene are investigated under the same growth conditions on polycrystalline copper foil in a three‐zone chemical vapor deposition (CVD) system, which has not thus far been researched in detail. The findings show that boron‐doped graphene films are successfully synthesized. The results enable the design of a recipe for thin‐film doped graphene grown with optimum optical transmission and sheet resistance via amending TEB molarity and growth time. Such changes suggest that the single‐layer graphene film with high homogeneity can be obtained for the film grown using 0.5 m triethylborane along with 10 min growth time as confirmed by Raman mapping and atomic force microscope (AFM) measurements. It is further revealed that increasing the amount of triethylborane and growth times leads to the formation of thicker graphene films. In addition, X‐ray photoelectron spectrometer (XPS) measurements indicate that boron atoms get into a honeycomb structure, thanks to substitutional doping. The findings of this study have significant implications for the implementation of boron‐doped graphene films in semiconductor‐based technology.

Borophene Nanosheets as High-Efficiency Catalysts for the Hydrogen Evolution Reaction.

Borophene has been predicted to have outstanding catalytic activity owing to its extreme electron deficiency and abundant active sites. However, no experimental results have been still reported for borophene application in high-efficiency catalysis. Here, a borophene nanosheet was prepared on a carbon cloth surface via chemical vapor deposition. The boron source is sodium borohydride and the carrier gas is hydrogen gas. The crystal structure of the borophene nanosheet highly matches that of a theoretical α'-borophene nanosheet. Borophene shows good electrocatalytic hydrogen evolution reaction (HER) ability with a 69 mV/dec Tafel slope and good cycling stability in a 0.5 M H2SO4 solution. The enhanced performance is ascribed to an abundant electrocatalytic active area and low resistance of charge transfer, which results from its rich surface active sites. The improvement has been revealed by first-principles calculations, which is originated from their inherent metallicity and abundant electrocatalytic active sites on the nanosheets' surface. Borophene's extraordinarily high activity and stability give rise to extensive investigation of the application of borophene in high-efficiency energy applications such as catalysts and batteries.

Hydrochemistry and source apportionment of boron, sulfate, and nitrate in the Fen River, a typical loess covered area in the eastern Chinese Loess Plateau

Fen River Basin (FRB) is water-deficient and strongly influenced by human activities in the eastern Chinese Loess Plateau. The spatio-temporal variation and controlling factors of hyrochemistry and quality, sources of high boron, sulfate, and nitrate of surface waters in FRB were unclear. Major ions, δ11B, δ15N, and δ18O in surface waters in dry season and wet season of FRB were analyzed and correlation analysis (CA), principal component analysis (PCA), self-organizing map (SOM), forward model, and Bayesian isotope mixing model (MixSIAR) were used to solve above problems. Results showed that average riverine δ11B, δ15N, and δ18O of FRB was 7.8‰, 11.2‰, and 1.3‰ (1SD), respectively. Dissolved solutes ranked midstream > downstream > upstream with water type of Na +-Cl-, Ca2+-Mg2+-Cl-, and Ca2+-HCO3-, respectively. Low dissolved solutes were in forest areas while high values were in cropland and city areas. SOM analysis indicated that hydrochemistry was both influenced by natural (upstream) and pollutional input (midstream and downstream) and variation between dry season and wet season was minor. The abnormally high boron concentrations were mainly from silicate weathering (43%) and evaporites dissolution of loess (32%), urban and industrial input contributed 15% of riverine boron. High SO42− (207 ± 267 mg/L, 1SD) was mainly from sulfates. δ15N and δ18O analysis indicated that nitrification was the primary N cycling process. Further, MixSIAR showed that NO3− was mainly from municipal sewage (∼67%) and the total contribution of chemical fertilizer and soil nitrogen was ∼30% with slightly higher values in upstream and wet season. Influenced by land-use types, evaporite dissolution, and anthropogenic input, water quality below midstream was worse and strict sewage reduction policies must be developed. This study highlights the significant influence of evaporite dissolution of loess and anthropogenic input (urban and industrial input for B and sewage for NO3−) on hydrochemistry and water quality.

Laser Processing of Diffusion Boronized Layer Produced on Monel® Alloy 400-Microstructure, Microhardness, Corrosion and Wear Resistance Tests.

The paper presents the results of studies of microstructure, mechanical and physicochemical properties of surface layers produced by laser modification of the diffusion boron layer on Monel® Alloy 400. The diffusion boron layers were produced at 950 °C for 6 h. The gas-contact method was used in an open retort furnace. The process was carried out in a powder mixture containing B4C carbide as a boron source. The next stage was the modification of the boron layer with a diode laser beam of a nominal power of 3 kW. A constant power of 1400 W of the laser beam was used. The scanning speed was variable (successively 5 m/min, 25 m/min, 50 m/min). In order to determine the best parameters, single tracks were created, after which multiple tracks were prepared using previously selected parameters. It was found that both the diffusion borided layer and the laser modified layer had better properties than the substrate material. Both these processes contributed to an increase in corrosion resistance, hardness and wear resistance. It was also found that laser modification caused a slight deterioration of the properties in comparison with the diffusion borided layer. However, the laser modification process resulted in the production of a much thicker layer.

Effect of Adding Different Boron Sources to Diets Containing Low Calcium and Phosphorus on Some Bone Parameters of Weaned Akkaraman Lambs

The aim of this study was to investigate the effect of addition of different boron sources (ulexide, colemanite, etibor-48) to diet containing low Ca, P on bone parameters and bone strength in weaned lambs. 50 Akkaraman single male lambs weaned at 2.5 months of age were used. Lambs were divided into 5 groups. Groups were; positive control, negative control, supplementation with colemanite, supplementation with etibor-48, supplementation with ulexide. Roughage and concentrated feed was given twice in day. At the end of 90 days, 6 animals from each group were slaughtered. The weight, dry weight, length, width and ash levels of the femoral and tibial bones were significantly increased in added boron (B) sources groups compared to negative control. With the supplementation of the colemanite and ulexide to diets, the femoral and tibial Ca content was higher compared to negative control. The P content in the femoral bone increased in groups added of all boron sources than that in negative control, also in tibial P content in the colemanite and ulexide groups increased compared to negative control. The supplementation of all B sources had improved B levels and breaking strength of bones compared to controls.

The Mineral Composition of Date Palm Fruits (Phoenix dactylifera L.) under Low to High Salinity Irrigation.

Adaptability to salinity varies between different varieties of date palm trees. This research aims to explore the long-term impact of different salinity irrigation levels on the mineral content of 13 date palm varieties grown in the United Arab Emirates (UAE). Date varieties were grown using three irrigation water salinity levels of 5, 10 and 15 dS m−1. The mineral composition (B, Ca, Cu, Fe, K, Mg, Na, P and Zn) of date palm fruits was determined using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). High salinity levels showed no effect on the mineral content of Ajwat AlMadinah, Naghal, Barhi, Shagri, Abu Maan, Jabri, Sukkari and Rothan varieties. All date varieties remained good sources of dietary potassium, magnesium, manganese and boron even at high salinity levels. Increased salinity had no effect on the percent Daily Value (%DV) categories of most of the analyzed minerals. While no genotypes showed a general adaptation to different saline environments, Barhi, Ajwat Al Madinah, Khinizi, Maktoumi and Shagri varieties were more stable towards salinity variation. In the UAE, the genotype x saline-environment interaction was found to be high which makes it impossible to attribute the variation in mineral content to a single varietal or salinity effect.

Citrate gel synthesis of vanadium diboride

Toward synthesizing vanadium diboride (VB2), mainly mechanochemical and carbothermic routes have been hitherto administired as well as combustion, self-propagating high temperature synthesis (SHS), and solid state metathesismethods. However, methods suggested to date do not deliberately deal with the oxidation state of the vanadium forming the oxide, formation conditions and morphology. Additionally, studies usually suggest an ultimate single reaction, disregarding side reactions. This narrow thermodynamic approach lacks key information in regards to the required conditions. Herein, this study reports the laboratory scale synthesis of VB2 nanopowders employing citrate gel method. The process is carried out using ammonium metavanadate (NH4VO3) as the vanadium source, boric acid (H3BO3) as the boron source, and citric acid (C6H8O7) as a chelating agent. Raw powder chelate is subjected to boro/carbothermic reactions under argon atmosphere in the range of 1100–1500 °C correlated with thermodynamic calculations with a 100 °C interval which are in good agreement with the experimental data. The resulting material is characterized to be at least 92% VB2 within the possibility of excessive graphitic carbon, carbon deficient vanadium carbide (V8C7) and/or non-stoichiometric VxBy(yx≤32) remaining as impurities. The formation mechanisms referring Liquid-Solid (LS) and Vapour-Solid (VS) reaction pathways throughout the major steps are described.