Differential Pulse Voltammetric Simultaneous Determination of Paracetamol and Omnipaque on Boron Doped Diamond Electrode: Application to Natural Tomato, Carrot, Cucumber Juices and Wastewater

This article describes the use of a boron-doped diamond electrode (BDDE) as an electrochemical sensor for the simultaneous determination of omnipaque (OMP) and paracetamol (PCM) in perchloric acid medium (HClO4 0.1 M) and in complex matrices such as tomato, carrot and cucumber juices and waste water from the Treichville University Hospital. Voltammetric studies allowed us to have well-defined oxidation peaks at distinct potentials of OMP (E = 0.5 V/SCE) and PCM (E = 0.7 V/SCE). Under optimized conditions, well-defined quantities of OMP and PCM, introduced simultaneously by metered additions, gave linear responses in concentration ranges of 259.8 - 467.2 μM for OMP and 58.73 - 116.3 μM PCM. The detection limits obtained are 7.23 μΜ and 3.6 μΜ respectively for OMP and PCM with recovery rates between 85.8% ± 0.1% and 92.6% ± 0.1% for OMP and between 99.9% ± 0.1% and 101.2% ± 0.4% for the PCM. This technique has been successfully used to simultaneously detect these pharmaceuticals in these complex environments. It allows recovery of OMP and PCM respectively up to 97.5% ± 0.0% and 91.6% ± 0.3% in tomato juice;100.0% ± 0.0% and 95.2% ± 0.2% in carrot juice;101.4% ± 0.1% and 97.3% ± 0.3% in cucumber juice;100.1% ± 0.9% and 100.9% ± 0.1% in wastewater. The relevance of this technique for the simultaneous detection of OMP and PCM in tomato, carrot, cucumber juices and in waste water can be studied in the context of the contamination of certain fruits and vegetables by the substances organic pharmaceuticals released into the environment without prior treatment.

Effects of oxygen/nitrogen co-incorporation on regulation of growth and properties of boron-doped diamond films

Regulation with nitrogen and oxygen co-doping on growth and properties of boron doped diamond films is studied by using laughing gas as dopant. As the concentration of laughing gas(N2O/C) increases from 0 to 10%, the growth rate of diamond film decreases gradually, and the nitrogen-vacancy(NV) center luminescence intensity increases first and then weakens. The results show that oxygen in laughing gas has a strong inhibitory effect on formation of NV centers, and the inhibitory effect would be stronger as the concentration of laughing gas increases. As a result, the film growth rate and nitrogen-related compensation donor decrease, beneficial to increase the acceptor concentration(~3.2×10^(19)cm^(-3)) in the film. Moreover, it is found that the optimal regulation with the quality and electrical properties of boron doped diamond films could be realized by adding appropriate laughing gas, especially the hole mobility(~700cm^(2)/V·s), which is beneficial to the realization of high-quality boron doped diamond films and high-level optoelectronic device applications in the future.

The Fluorination of Boron-Doped Graphene for CF_(x) Cathode with Ultrahigh Energy Density

The enhancement of the fluorination degree of carbon fluorides(CF_(x))compounds is the most effective method to improve the energy densities of Li/CF_(x)batteries because the specific capacity of CF_(x)is proportional to the molar ratio of F to C atoms(F/C).In this study,B-doped graphene(BG)is prepared by using boric acid as the doping source and then the prepared BG is utilized as the starting material for the preparation of CF_(x).The B-doping enhances the F/C ratio of CF_(x)without hindering the electrochemical activity of the C–F bond.During the fluorination process,B-containing functional groups are removed from the graphene lattice.This facilitates the formation of a defect-rich graphene matrix,which not only enhances the F/C ratio due to abundant perfluorinated groups at the defective edges but also serves as the active site for extra Li+storage.The prepared CF_(x)exhibits the maximum specific capacity of 1204 mAh g^(−1),which is 39.2%higher than that of CF_(x)obtained directly from graphene oxide(without B-doping).An unprecedented energy density of 2974 Wh kg^(−1)is achieved for the asprepared CF_(x)samples,which is significantly higher than the theoretically calculated energy density of commercially available fluorinated graphite(2180 Wh kg^(−1)).Therefore,this study demonstrates a great potential of B-doping to realize the ultrahigh energy density of CF_(x)cathodes for practical applications.

Designing interstitial boron-doped tunnel-type vanadium dioxide cathode for enhancing zinc ion storage capability

Chemical doping is a powerful method to intrinsically tailor the electrochemical properties of electrode materials.Here,an interstitial boron-doped tunnel-type VO_(2)(B)is constructed via a facile hydrothermal method.Various analysis techniques demonstrate that boron resides in the interstitial site of VO_(2)(B)and such interstitial doping can boost the zinc storage kinetics and structural stability of VO_(2)(B)cathode during cycling.Interestingly,we found that the boron doping level has a saturation limit peculiarity as proved by the quantitative analysis.Notably,the 2 at.%boron-doped VO_(2)(B)shows enhanced zinc ion storage performance with a high storage capacity of 281.7 mAh g^(-1) at 0.1 A g^(-1),excellent rate performance of 142.2 mAh g^(-1) at 20 A g^(-1),and long cycle stability up to 1000 cycles with the capacity retention of 133.3 mAh g^(-1) at 5 A g^(-1).Additionally,the successful preparation of the boron-doped tunneltype α-MnO_(2) further indicates that the interstitial boron doping approach is a general strategy,which supplies a new chance to design other types of functional electrode materials for multivalence batteries.

Boron-doped lamellar porous carbon supported copper catalyst for dimethyl oxalate hydrogenation

Doping heteroatoms on carbon materials could bring some special advantages for using as catalyst support.In this work, a boron doped lamellar porous carbon(B-LPC) was prepared facilely and utilized as carbonbased support to construct Cu/B-LPC catalyst for dimethyl oxalate(DMO) hydrogenation. Doping boron could make the B-LPC own more defects on surface and bigger pore size than B-free LPC, which were beneficial to disperse and anchor Cu nanoparticles. Moreover, the interaction between Cu species and B-LPC could be strengthened by the doped B, which not only stabilized the Cu nanoparticles, but also tuned the valence of Cu species to maintain more Cu^(+). Therefore, the B-doped Cu/B-LPC catalyst exhibited stronger hydrogenation ability and obtained higher alcohols selectivity than Cu/LPC, as well as high stability without decrease of DMO conversion and ethylene glycol selectivity even after 300 h of reaction at 240℃.

Boron doped 1T phase MoS_(2) as a cocatalyst for promoting photocatalytic H_(2) evolution of g-C_(3)N_(4) nanosheets

As one of the 2D transition metal sulfides,1T phase MoS_(2) nanosheets(NSs)have been studied because of their distinguished conductivity and suitable electronic structure.Nevertheless,the active sites are limited to a small number of edge sites only,while the basal plane is catalytically inert.Herein,we report that boron(B)doped 1T phase MoS_(2) NSs can replace precious metals as a co-catalyst to assist in photocatalytic H_(2) production of 2D layered g-C_(3)N_(4) nanosheets(g-C_(3)N_(4) NSs).The H_(2) evolution rate of prepared B-MoS_(2)@g-C_(3)N_(4) composites with 15 wt%B-MoS_(2)(B-MoS_(2)@g-C_(3)N_(4)–15,1612.75μmol h^(−1) g^(−1))is 52.33 times of pure g-C_(3)N_(4) NSs(30.82μmol h^(−1) g^(−1)).Furthermore,the apparent quantum efficiency(AQE)of B-MoS_(2)@g-C_(3)N_(4)–15 composites under the light atλ=370 nm is calculated and reaches 5.54%.The excellent photocatalytic performance of B-MoS_(2)@g-C_(3)N_(4)–15 composites is attributed to the B ions doping inducing the distortion of 1T phase MoS_(2) crystal,which can activate more base planes to offer more active sites for H_(2) evolution reaction(HER).This work of B-MoS_(2)@g-C_(3)N_(4) composites offers experience in the progress of effective and low-price photocatalysts for HER.

Structure and electrical properties of polysilicon films doped with ammonium tetraborate tetrahydrate

Here,p-type polysilicon films are fabricated by ex-situ doping method with ammonium tetraborate tetrahydrate(ATT)as the boron source,named ATT-pPoly.The effects of ATT on the properties of polysilicon films are comprehensively analyzed.The Raman spectra reveal that the ATT-pPoly film is composed of grain boundary and crystalline regions.The preferred orientation is the(111)direction.The grain size increases from 16−23 nm to 21−47 nm,by~70%on average.Comparing with other reported films,Hall measurements reveal that the ATT-pPoly film has a higher carrier concentration(>10^(20)cm^(−3))and higher carrier mobility(>30 cm2/(V·s)).The superior properties of the ATT-pPoly film are attributed to the heavy doping and improved grain size.Heavy doping property is proved by the mean sheet resistance(Rsheet,m)and distribution profile.The R_(sheet,m)decreases by more than 30%,and it can be further decreased by 90%if the annealing temperature or duration is increased.The boron concentration of ATT-pPoly film annealed at 950℃ for 45 min is~3×10^(20)cm^(−3),and the distribution is nearly the same,except near the surface.Besides,the standard deviation coefficient(σ)of Rsheet,m is less than 5.0%,which verifies the excellent uniformity of ATT-pPoly film.

Preparation, characterization and electrochemical properties of boron-doped diamond films on Nb substrates

A series of boron-doped polycrystalline diamond films were prepared by hot filament （HF） chemical vapor deposition on Nb substrates. The effects of B/C ratio of reaction gas on film morphology, growth rate, chemical bonding states, phase composition and electrochemical properties of each deposited sample were studied by scanning electron microscopy, Raman spectra, X-ray diffraction, microhardness indentation, and electrochemical analysis. Results show that the average grain size of diamond and the growth rate decrease with increasing the B/C ratio. The diamond films exhibit excellent adhesion under Vickers microhardness testing （9.8 N load）. The sample with 2% B/C ratio has a wider potential window and a lower background current as well as a faster redox reaction rate in H2SO4 solution and KFe（CN）6 redox system compared with other doping level electrodes.

Effect of oxygen on regulation of properties of moderately boron-doped diamond films

Regulation of oxygen on properties of moderately boron-doped diamond films is fully investigated.Results show that,with adding a small amount of oxygen(oxygen-to-carbon ratio<5.0%),the crystal quality of diamond is improved,and a suppression effect of residual nitrogen is observed.With increasing ratio of O/C from 2.5%to 20.0%,the hole concentration is firstly increased then reduced.This change of hole concentration is also explained.Moreover,the results of Hall effect measurement with temperatures from 300 K to 825 K show that,with adding a small amount of oxygen,boron and oxygen complex structures(especially B_(3)O and B_(4)O)are formed and exhibit as shallow donor in diamond,which results in increase of donor concentration.With further increase of ratio of O/C,the inhibitory behaviors of oxygen on boron leads to decrease of acceptor concentration(the optical emission spectroscopy has shown that it is decreased with ratio of O/C more than 10.0%).This work demonstrates that oxygen-doping induced increasement of the crystalline and surface quality could be restored by the co-doping with oxygen.The technique could achieve boron-doped diamond films with both high quality and acceptable hole concentration,which is applicable to electronic level of usage.

Effect of deposition temperature on properties of boron-doped diamond films on tungsten carbide substrate

Boron-doped diamond(BDD)films were deposited on the tungsten carbide substrates at different substrate temperatures ranging from 450 to 850°C by hot filament chemical vapor deposition(HFCVD)method.The effect of deposition temperature on the properties of the boron-doped diamond films on tungsten carbide substrate was investigated.It is found that boron doping obviously enhances the growth rate of diamond films.A relatively high growth rate of 544 nm/h was obtained for the BDD film deposited on the tungsten carbide at 650°C.The added boron-containing precursor gas apparently reduced activation energy of film growth to be 53.1 kJ/mol,thus accelerated the rate of deposition chemical reaction.Moreover,Raman and XRD analysis showed that heavy boron doping(750 and 850°C)deteriorated the diamond crystallinity and produced a high defect density in the BDD films.Overall,600-700°C is found to be an optimum substrate temperature range for depositing BDD films on tungsten carbide substrate.

Electronic properties of graphene nanoribbon doped by boron/nitrogen pair:a first-principles study

By using the first-principles calculations, the electronic properties of graphene nanoribbon （GNR） doped by boron/nitrogen （B/N） bonded pair are investigated. It is found that B/N bonded pair tends to be doped at the edges of GNR and B/N pair doping in GNR is easier to carry out than single B doping and unbonded B/N co-doping in GNR. The electronic structure of GNR doped by B/N pair is very sensitive to doping site besides the ribbon width and chirality. Moreover, B/N pair doping can selectively adjust the energy gap of armchair GNR and can induce the semimetal-semiconductor transmission for zigzag GNR. This fact may lead to a possible method for energy band engineering of GNRs and benefit the design of graphene electronic device.

Synthesis and Antimicrobial Activity of Boron-doped Titania Nano-materials

Antibacterial activity of boron-doped TiO2(B/TiO2) nano-materials under visible light irradiation and in the dark was investigated. A simple sol-gel method was used to synthesize TiO2 nano-materials. X-ray diffraction pattern of B/TiO2 nano-materials represents the diffraction peaks relating to the crystal planes of TiO2(anatase and rutile). X-ray photoelectron spectroscopy result shows that part of boron ions incorporates into TiO2 lattice to form a possible chemical environment like Ti O B and the rest exist in the form of B2O3. The study on antibacterial effect of B/TiO2 nano-materials on fungal Candida albicans(ATCC10231), Gram-negative Escherichia coli(ATCC25922) and Gram-positive Staphylococcus aureus(ATCC6538) shows that the antibacterial action is more significant on Candida albicans than on Escherichia coli and Staphylococcus aureus. Under visible light irradiation, the antibacterial activity is superior to that in the dark.

Effect of nitrogen on deposition and field emission properties of boron-doped micro-and nano-crystalline diamond films

In this paper,we report the effect of nitrogen on the deposition and properties of boron doped diamond films synthesized by hot filament chemical vapor deposition.The diamond films consisting of micro-grains(nano-grains) were realized with low(high) boron source flow rate during the growth processes.The transition of micro-grains to nano-grains is speculated to be strongly(weekly) related with the boron(nitrogen) flow rate.The grain size and Raman spectral feature vary insignificantly as a function of the nitrogen introduction at a certain boron flow rate.The variation of electron field emission characteristics dependent on nitrogen is different between microcrystalline and nanocrystalline boron doped diamond samples,which are related to the combined phase composition,boron doping level and texture structure.There is an optimum nitrogen proportion to improve the field emission properties of the boron-doped films.

Cytotoxicity of Boron-Doped Nanocrystalline Diamond Films Prepared by Microwave Plasma Chemical Vapor Deposition

Boron-doped nanocrystalline diamond（NCD） exhibits extraordinary mechanical properties and chemical stability,making it highly suitable for biomedical applications.For implant materials,the impact of boron-doped NCD films on the character of cell growth（i.e.,adhesion,proliferation） is very important.Boron-doped NCD films with resistivity of 10-2Ω·cm were grown on Si substrates by the microwave plasma chemical vapor deposition（MPCVD） process with H2 bubbled B2O3.The crystal structure,diamond character,surface morphology,and surface roughness of the boron-doped NCD films were analyzed using different characterization methods,such as X-ray diffraction（XRD）,Raman spectroscopy,scanning electron microscopy（SEM） and atomic force microscopy（AFM）.The contact potential difference and possible boron distribution within the film were studied with a scanning kelvin force microscope（SKFM）.The cytotoxicity of films was studied by in vitro tests,including fluorescence microscopy,SEM and MTT assay.Results indicated that the surface roughness value of NCD films was 56.6 nm and boron was probably accumulated at the boundaries between diamond agglomerates.MG-63 cells adhered well and exhibited a significant growth on the surface of films,suggesting that the boron-doped NCD films were non-toxic to cells.

Combined DFT and experiment:Stabilizing the electrochemical interfaces via boron Lewis acids

The incorporation of boron into carbon material can significantly enhance its capacity performances.However,the origin of the promotion effect of boron doping on electrochemical performances is still unclear,in part due to the inadequate exposure of boron configurations resulting from the complexity of traditional carbon materials.To overcome this issue,herein,a series of boron-doped graphene with highly-exposed boron configurations are prepared by tuning annealing temperature.Then the correlation between boron configurations and the electrochemical performances is investigated.The combination of density-functional theory(DFT)computation and NH3-TPD/Py-FTIR indicates that the BCO_(2)configuration formed on the surface of graphene is easier to accept lone-pair electrons than BC_(2)O and BC_(3)configurations due to the stronger Lewis acidity.Such an electronic structure can effectively reduce the number of unstable electron donors and stabilize the electrochemical interface,which is proved by NMR,and critical for improving the electrochemical performances.Further experiments confirm that the optimized BG800 with the largest amount of BCO_(2)configuration presents ultralow leak current,improved cyclic stability,and better rate performance in SBPBF4/PC.This work would provide an insight into the design of high-performance boron-doped carbon materials towards energy storage.

Hydrophilic bi-functional B-doped g-C_(3)N_(4) hierarchical architecture for excellent photocatalytic H_(2)O_(2) production and photoelectrochemical water splitting

Graphitic carbon nitride(g-C_(3)N_(4))has attracted great interest in photocatalysis and photoelectrocatalysis.However,their poor hydrophilicity poses a great challenge for their applications in aqueous environment.Here,we demonstrate synthesis of a hydrophilic bi-functional hierarchical architecture by the assembly of B-doped g-C_(3)N_(4)nanoplatelets.Such hierarchical B-doped g-C_(3)N_(4)material enables full utilization of their highly enhanced visible light absorption and photogenerated carrier separation in aqueous medium,leading to an excellent photocatalytic H_(2)O_(2)production rate of 4240.3μM g^(-1)h^(-1),2.84,2.64 and 2.13 times higher than that of the bulk g-C_(3)N_(4),g-C_(3)N_(4)nanoplatelets and bulk B doped g-C_(3)N_(4),respectively.Photoanodes based on these hierarchical architectures can generate an unprecedented photocurrent density of 1.72 m A cm^(-2)at 1.23 V under AM 1.5 G illumination for photoelectrochemical water splitting.This work makes a fundamental improvement towards large-scale exploitation of highly active,hydrophilic and stable metal-free g-C_(3)N_(4)photocatalysts for various practical applications.

Synthesis of N-type semiconductor diamonds with sulfur,boron co-doping in FeNiMnCo-C system at high pressure and high temperature

A series of diamonds with boron and sulfur co-doping were synthesized in the Fe Ni Mn Co-C system by temperature gradient growth（TGG） under high pressure and high temperature（HPHT）. Because of differences in additives, the resulting diamond crystals were colorless, blue-black, or yellow. Their morphologies were slab, tower, or minaret-like. Analysis of the x-ray photoelectron spectra（XPS） of these diamonds shows the presence of B, S, and N in samples from which N was not eliminated. But only the B dopant was assuredly incorporated in the samples from which N was eliminated. Resistivity and Hall mobility were 8.510 Ω·cm and 760.870 cm^2/V·s, respectively, for a P-type diamond sample from which nitrogen was eliminated. Correspondingly, resistivity and Hall mobility were 4.211×10^5 Ω·cm and 76.300 cmΩ2/V·s for an N-type diamond sample from which nitrogen was not eliminated. Large N-type diamonds of type Ib with B–S doping were acquired.

A Comparative Study of Boron and Phosphorus Doping Effects in SiC: H Films Prepared by ECR-CVD

Hydrogenated silicon carbide films (SiC:H) were deposited using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) technique from a mixture of methane, silane and hydrogen, and using diborane and phosphine as doping gases. The effects of changes in the microwave power on the deposition rate and optical bandgap were investigated, and variations in the photoand dark-conductivities and activation energy were studied in conjunction with film analysis using the Raman scattering technique. In the case of boron-doped samples, the conductivity increased rapidly to a maximum, followed by rapid reduction at high microwave power. The ratio of the photo- to dark-conductivity (σph/σd) peaked at microwave power of ~600 W. Under conditions of high microwave power, Raman scattering analysis showed evidence of the formation and increase in the silicon microcrystalline and diamond-like phases in the films, the former of which could account for the rapid increase and the latter the subsequent decrease in the conductivity.In the case of phosphorusdoped SiC:H samples, it was found that increase in the microwave power has the effect of enhancing the formation of the silicon microcrystalline phase in the films which occurred in correspondence to a rapid increase in the conductivity and reduction in the activation energy The conductivity increase stabilised in samples deposited at microwave power exceeding 500 W probably as a result of dopant saturation. Results from Raman scattering measurements also showed that phosphorus doping had the effect of enhancing the formation of the silicon microcrystals in the film whereas the presence of boron had the effect of preserving the amorphous structure.

Au nanospheres modified boron-doped diamond microelectrode grown via hydrogen plasma etching solid doping source for dopamine detection

Boron doped diamond(BDD)electrode is a promising electrochemical material for detecting dopamine level in the human’s body.In this work,we developed a new doping source-graphite and solid boron oxide powders to synthesize BDD film with microwave plasma chemical vapor deposition,so as to avoid using toxic or corrosive dopants,such as boroethane and trimethylborate.The synthesized BDD film is pinhole free and with high doping density of 8.44×10^20 cm^-3 calculated from the Raman spectroscopy.Subsequently,Au nanospheres were decorated on the surface of BDD film to improve electrochemical performance of the BDD film.The Au nanoparticles modified BDD electrode demonstrates an excellent electrochemical response,a high sensitivity(in the range of 5μM-1 m M),and a low detection limit(~0.8μM)for detecting dopamine.

Preparation of Large-Scale Double-Side BDD Electrodes and Their Electrochemical Performances

Boron doped diamond(BDD)performs well in electrochemical oxidation for organic pollutants thanks to its wide electrochemical window and superior chemical stability.We presented a method to obtain well-adherent large-scale BDD/Nb electrode by the modified hot filament chemical vapor deposition system(HFCVD).SiC particles were sand blasted to enhance the adhesion of BDD coating.The BDD coating was then deposited on both sides of Nb which was placed vertically and closely with filament grids on both sides.The BDD/Nb electrodes had no deformation because the thermal deformations of the BDD films on both sides of the Nb substrate conteracted each other during cooling process after deposition.The surface morphology and purity of the BDD/Nb electrode were analyzed by Raman and scanning elestron microscope(SEM)techniques.Scratch test was used to investigate the adhesion of BDD films.The electrochemical performances were measured by cyclic voltammetry test.The BDD electrode at the B/C ratio of 2 000×10^(-6) held a higher oxygen evolution potential thanks to its high sp3 carbon content.Accelerated life test illustrated that the sandblasting pretreatment obviously enhanced the adhesion of BDD coating which resulted in a longer service duration than the un-sandblasted one.