Boron Doping Research Articles

Graphitic Carbon Nitride Supported Boron Quantum Dots: A Transition Metal Free Alternative for Di-nitrogen to Ammonia Reaction.

Presently, a sustainable electrochemical Nitrogen Reduction Reaction (NRR) has been essentially found to be viable on transition metal-based catalysts. However, metal free catalysts, being cost effective and non-corrosive, present an ideal solution for a sustainable world. Herein, through a DFT based study, we demonstrate a metal free NRR catalysts, boron quantum dots with 13 atoms as a case study, and their chemically modified counterparts when anchored on graphitic carbon nitride (g-C3N4) surface. The best catalyst among the studied, a silicon doped boron quantum dot with a cagelike structure, is found to favour the dinitrogen to ammonia reaction path way with a low liming potential and potential rate-determining step (PDS) of -0.11 V and 0.27 eV, respectively. The present work demonstrates as to how boron quantum dots, which are reported to be experimentally synthesised, can be exploited for ammonia synthesis when supported on surface. These catalysts effectively suppress the HER, thus establishing its suitability as an ideal catalyst. The work also represents a futuristic pathway towards a metal free catalyst for NRR.

Boron modification of AuRh mesoporous nanotubes for electro-reduction of nitrogen to ammonia.

Electrocatalytic nitrogen reduction reaction (NRR) is a prospective tactics for ammonia synthesis. However, the development of highly active NRR electrocatalysts is still challenging owing to the difficult activation of nitrogen and competitive hydrogen evolution reaction (HER). Here, we synthesized boron-doped AuRh mesoporous nanotubes (B-AuRh MNTs) via dual-template method coupled with boron doping. The mesoporous nanotube structure has high specific surface area and excellent surface permeability. Thereby, the B-AuRh MNTs exhibit NH3 yield of 13.3 μg h-1 mg-1cat and Faraday efficiency of 22.5% under 0.1 M Na2SO4. The doping of boron with weak hydrogen adsorption can generate electronic effect, thus stimulating the activation of N2 molecules and effectively inhibiting HER. This study proposes a universal method for the preparation of boron-doped Pd-based catalysts, which is beneficial to improve the NRR performance.&#xD.

The performance of phosphorus hexarbide monolayer as lithium-ion battery anode materials by boron and sulfur doping

The performance of phosphorus hexarbide monolayer as lithium-ion battery anode materials by boron and sulfur doping

An Interstitial Boron Inserted Metastable Hexagonal Rh Nanocrystal for Efficient Hydrogen Oxidation Electrocatalysis

AbstractConstructing metastable phase structure plays an important role in changing the physicochemical properties and improving the catalytic performance of nanocrystals. Unfortunately, the synthesis of metastable phase metallic nanocrystals is highly challenging, mainly due to the thermodynamically unstable ground‐state. Here, we report a synthesis of unconventional metastable hexagonal rhodium nanocrystal (Bint−Rhhcp/C) via interstitial boron insertion. The insertion of boron atoms into the interstitial sites of cubic Rh lattice not only induces the atomic arrangements from face‐centered cubic (fcc) to hexagonal close‐packed (hcp), but also stabilizes the metastable hexagonal Rh structure. Benefiting from the phase transition and interstitial boron doping, the Bint−Rhhcp/C catalyst exhibits remarkable catalytic performance toward hydrogen oxidation reaction (HOR) under alkaline media, with a mass activity of 1.413 mA μgPGM−1. Experimental measurements including in situ surface‐enhanced infrared absorption spectroscopy (SEIRAS) and density functional theory (DFT) calculations indicate that the strengthened adsorption of hydroxyl species on the electrode surface of Bint−Rhhcp/C is responsible for the reconstruction of interfacial water structure and increased water proportions in the gap region in the electric double layers. As a result, the increased water connectivity and hydrogen bond network facilitate high‐efficiency hydrogen transfer across the interface, thereby boost the alkaline HOR performance.

Boron doped Ti2Nb10O29 nanosheets core/shell arrays as advanced high-energy anode for fast lithium ions storage

Titanium niobium oxide (Ti2Nb10O29, TNO) as anode for high-energy lithium ion batteries (LIBs) typically suffers from sluggish kinetics and reaction activity because of its inferior electronic/ionic conductivity and easy aggregation feature. Herein, we present a novel synergistic strategy to tackle such problems of TNO by combining boron (B) doping and porous carbon nanosheet (PCN) arrays support. Experiment results and theoretical calculations demonstrate that the doped B substantially ameliorates the intrinsic electronic/ionic conductivity of TNO, increases the oxygen vacancy content in TNO, and accelerates lithium ion diffusion. Meanwhile, high-conductive PCN arrays as growth skeleton can avoid the agglomeration of B-TNO particles. As a result, the as-prepared PCN/B-TNO anode delivers an impressive specific capacity of 303 mAh g−1 at 1 C and 104 mAh g−1 at 20 C, superior to the PCN/TNO anode. Additionally, PCN/B-TNO anode also possesses a prominent long-time durability (85 % capacity retention after 2000 cycles). Our work paves a new way of rationally constructing high-energy anodes for fast energy storage and release.

Characterization and Optimization of a Locally Boron-Doped Diamond Tool for Self-sensing of Cutting Temperature

High-sensitivity and rapid-response measurements of micro zone cutting temperature are crucial for characterizing and optimizing machining states in the ultra-precision cutting process. This innovative method uses a locally boron-doped diamond (LBDD) tool itself as the sensor for in-process measurements of cutting temperature. However, the heterogeneity of boron doping and the resulting lattice distortions considerably affect the mechanical properties and temperature-sensing performances of the tool. In this work, optimized synthesis processes and structural designs for LBDD tools that function as self-sensing cutting temperature devices were proposed. Annealing treatments under high-pressure conditions were conducted to promote the diffusion and ionization of boron multimers in the boron-doped diamond zone, thereby enhancing the crystal quality and semiconductor electrical properties of the LBDD. Various LBDDs with thin-layer temperature-sensing structures of different doping concentrations and thicknesses were synthesized. The optimal components and structures were identified as the temperature-sensing cutting tool through comparative analyses of temperature measurement capabilities and semiconductor properties. The selected tool was employed for in-process cutting temperature measurement during single-point diamond turning of copper and carbon fiber. Results indicate that the LBDD tool can accurately monitor cutting temperature during steady cutting processes and identify the micromorphological features of the machined surfaces based on cutting temperature characteristics. These insights are pivotal for controlling cutting temperature and refining the ultra-precision cutting process.

Electron-Spin Relaxation in Boron-Doped Graphene Nanoribbons.

Boron-doped graphene nanoribbons are promising platforms for developing organic materials with magnetic properties. Boron dopants can be used to create localized magnetic states in nanoribbons with tunable interactions. Controlling the coherence times of these magnetic states is the very first step in designing materials for quantum computation or information storage. In this work, we address the connection between the relaxation time and the position of the dopants for a series of boron-doped graphene nanofragments. We combine Redfield theory and ab initio calculations of magnetic properties to unveil the mechanism that governs spin relaxation in solution. We demonstrate that relaxation times can be in the order of 1 ms for the selected graphene nanofragments. A detailed analysis of the relaxation mechanism reveals that the spin decoherence is fundamentally driven by fluctuations of the spin-orbit coupling, and the hyperfine interaction facilitated by the thermal motion of the graphene nanofragments. The close connection between relaxation time, hyperfine interaction and the spin-orbit coupling offers the perspective of designing attractive materials with long-lived spin states.

Synthesis structural and thermal properties of 30Li2O-20ZnO-xB2O3-(50-x) P2O5 borophosphate glasses with varying B2O3 content

A borophosphate system with the composition 30Li2O-20ZnO-xB2O3-(50-x) P2O5 (where x = 0, 10, and 45 mol%) has been successfully synthesized using the conventional melt-quenching technique. The resulting materials were analyzed for their amorphous and vitreous properties using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The study focused on the impact of boron doping on thermal properties, specifically examining the glass transition temperature (Tg), crystallization temperature (Tc), and overall thermal stability. Structural analysis was further supported by Raman spectroscopy, providing insights into the network structure of the glasses. Morphological characteristics and elemental composition were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS).

Improving shape memory effect in Fe-Mn-Si-based alloys by reducing annealing twin boundaries through trace boron doping

Previous work has shown that the shape memory effect (SME) exhibited a strong negative dependence on the density of annealing twin boundaries (ATBs) in Fe-Mn-Si-based alloys. Reducing the density of ATBs has thus been an effective way to improve the SME of Fe-Mn-Si-based alloys. This study investigated the effects of trace B doping on the density of ATBs and the resultant SME in solution-treated Fe-Mn-Si-based alloys. Results indicated that doping 89 ppm B effectively reduced the density of ATBs in the solution-treated Fe-Mn-Si-based alloy. Consequently, its SME was remarkably improved. The maximum shape recovery strain reached 2.7 % in the B-doped alloy, 1.3 % higher than in the alloy without B doping. This work demonstrates a new avenue to improve the SME by doping trace B, which is of significance for the fabrication of Fe-Mn-Si-based shape memory alloys in a more cost-effective manner.

Interfacial Engineering of MoxSy via Boron-Doping for Electrochemical N2-to-NH3 Conversion.

The electrocatalytic synthesis of ammonia (NH3) through the nitrogen reduction reaction (NRR) under ambient temperature and pressure is emerging as an alternative approach to the conventional Haber-Bosch process. However, it remains a significant challenge due to poor kinetics, low nitrogen (N2) solubility in aqueous electrolytes, and the competing hydrogen evolution reaction (HER), which can significantly impact NH3 production rates and Faradaic efficiency (FE). Herein, a rationally designed boron-doped molybdenum sulfide (B-Mo-MoxSy) electrocatalyst is reported that effectively enhances N2 reduction to NH3 with an onset potential of -0.15V versus RHE, achieving a FE of 78% and an NH3 yield of 5.83µg h⁻¹ cm⁻2 in a 0.05m H2SO4(aq). Theoretical studies suggest that the effectiveness of NRR originates from electron density redistribution due to boron (B) doping, which provides an ideal pathway for nitrogenous species to bind with electron-deficient B sites. This work demonstrates a significant exploration, showing that Mo-based electrocatalysts are capable of facilitating artificial N2 fixation.

Effects of boron and manganese doping on electrical poling and properties of 0.94(Bi0.5Na0.5)TiO3-0.06BaTiO3 piezoelectric ceramics

Undoped, 1 mol % B3+ doped (1B), and 1 mol% B3+ - 1 mol% Mn3+ co-doped (1B-1Mn) 0.94(Bi0.5Na0.5)TiO3-0.06BaTiO3 (BNT-6BT) lead-free piezoelectric ceramics were produced by solid-state reaction method. Samples were shaped into disc pellets using high-purity perovskite phase powders of all compositions and were sintered at 1150 °C for 12 h in air. After the structural characterizations of the produced materials by using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Archimedes method, electrical property measurements were peformed for the undoped and variously doped samples. As it is a critical step for the improved piezoelectric properties, poling conditions were systematically studied in the range of 5–20 min time duration, at temperatures from room temperature (RT) up to 80 °C, and electric fields between 3 and 5 kV/mm. Major electrical properties were determined in terms of dielectric constant (εr), dielectric loss (tanδ), piezoelectric coefficient (d33), maximum polarization (Pmax), remanent polarization (Pr), coercive field (EC), and maximum strain (Smax). The measured values were compared for undoped, 1B and 1B-1Mn ceramics. The highest εr, d33, Pmax, Pr, and Smax values were obtained for 1B composition after the poling process at RT. Although all other properties were greatly improved by B3+ doping, high values of EC (26.87 kV/cm) and tanδ (0.0314) are considered to be detrimental for many applications. It has been observed that 1B-1Mn composition exhibited significantly reduced EC (22.73 kV/cm) and tanδ (0,0170) values with only a slight drop in other properties. It was also noted that Mn3+ doping increased the poling electric field and temperature, while the influence of poling time on properties was found to be quite negligible for all compositions in this study. As a result, the doping-dependent optimized poling conditions were determined for 1B-1Mn co-doped BNT-6BT lead-free piezoelectric ceramics in this study.

3D printer fabrication of boron doped Cu-MWCNT/PLA electrodes: Investigation of its efficiency in electrocatalytic hydrogen production

In this study, three-dimensional (3D) electrodes based on MWCNT-Cu/PLA with high electrocatalytic efficiency, large surface area and different amounts of nano‑boron doped MWCNT-Cu/PLA were fabricated using Fused Granular Fabrication (FGF) method with a 3D printer. When FE-SEM images are examined, MWCNT fibers and copper particles are seen more clearly on the surface due to the formation of more dense conductive networks between the conductive carbon fibers trapped in the PLA structure due to the increasing amount of boron. When XRD results are examined, it is observed that the characteristic peaks belonging to the face-centered cubic structure of Cu are dominant and the crystal size increases as MWCNT addition and boron doping increase. When Raman spectra were analyzed to investigate the internal structural changes of MWCNTs, three characteristic bands corresponding to the D band (defect), G band (graphite band) and G' band (D overtone) of MWCNTs were determined and it was observed that the ID/IG ratio decreased with increasing boron doping compared to MWCNT-Cu/PLA electrode. The B1s spectrum of the 3D 0.8B@MWCNT-Cu/PLA electrode confirmed the presence of boron with the peak corresponding to B@C bonds at 191.2 eV. The obtained 3D electrocatalysts were used as cathodes in an electrolysis cell in aqueous solution containing 1 M KOH and their catalytic efficiency in hydrogen evolution reaction (HER) was tested. In order to increase the activity of the 3D electrodes, unlike the literature, they were activated by electrochemical activation process without using organic solvent and HER measurements of the activated electrodes were performed. Before activation, the charge transfer resistance (Rct) value of the Cu/PLA electrode, which was 6219.00 Ω cm−2, decreased to 681.90 Ω cm−2 after 5 % MWCNT doping. It is seen that with boron doping, a greater decrease in Rct value is realized, reaching values of 66.50–74.56 Ω cm−2. The cathodic Tafel slopes show that the Volmer reaction is the rate-determining step for HER and the rate-determining step is the electrochemical adsorption of hydrogen on the metal surface. In addition, energy efficiency tests of the 3D electrodes in HER were also performed and electrochemically active surface areas were determined. Thus, this study has taken an important step toward using 3D electrocatalysts, which are produced with more cost and more flexible designs, unlike previous production techniques, for hydrogen energy production.

Boron-doped TiO2 nanoparticles for improved photoelectrochemical response via enhanced surface area and visible light absorption

The present study introduces boron doping into TiO2 nanoparticles to synthesize boron-doped TiO2 samples. The structural and morphological properties of the pristine and doped samples are investigated using X-ray diffraction, Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) and High Resolution Transmission Electron Microscopy (HRTEM) techniques. Photoelectrochemical measurements have confirmed that a 3 wt % concentration of boron doped TiO2 nanoparticles shows improved photoelectrochemical response compared to pristine TiO2 nanoparticles. An ∼285-fold improvement (∼0.97 mA/cm2 at 0.81 V vs RHE) is observed in 3 wt % boron doped TiO2 nanoparticles array as compared to the pristine (3.4 μA/cm2 at 0.81 V vs RHE) photoanode samples. Moreover, the enhanced surface area, suppressed recombination, effective charge separation/transport of photogenerated charge carriers, and improved visible light absorption due to boron doping result in a remarkably high current density.

Excitation wavelength and time dependent colour tunable room temperature phosphorescence from boron doped carbon nanodots.

Developing metal free room temperature phosphorescence (RTP) materials have received tremendous attention due its potential application in various fields such as sensing, optoelectronics and anticounterfeiting. Herein, we have synthesized an excitation wavelength and time dependent phosphorescent boron doped carbon nanodots (BCNDs) by thermal treatment of ethanolamine and boric acid at 240°C, where boric acid act as both doping and host agents. The obtained BCNDs display blue to orange fluorescence in both aqueous medium and solid state. In addition, the BCNDs display tunable orange-yellow-green phosphorescence in solid state under UV and visible light, lasting upto 10s, visible to naked eye. The boron and nitrogen doping regulates the band gap of the BCNDs, resulting the phosphorescence colour tunability. The average phosphorescence lifetime and quantum yield of BCNDs are found to be 1.27s and 8.61% respectively. Based on the optical properties, the BCNDs are applied as security ink in information encryption and security marking. Hence, this work can promote the development of metal free phosphorescent carbon based materials which may find application in various emerging fields.

DFT and AIMD Evaluation of Boron‐Doped Biphenylene as an Anode Material in Lithium‐ and Sodium‐Ion Batteries

AbstractDesign and proposal of high‐efficiency anode materials are crucial for the development of batteries with enhanced power and energy density, a key factor in their commercialization. This study presents a comparative theoretical study to evaluate the potential of boron‐doped biphenylene (B‐BP) as an anode electrode in lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs). Current research investigates the impact of boron doping on the structural, electronic, and stability properties of pristine biphenylene. Computational calculations reveal strong interactions between charge carriers (Li and Na atoms) and the proposed anode with a charge transfer from Li/Na atom to the surface. According to kinetic studies, a low energy barrier for charge carrier diffusion has been obtained which makes it a promising candidate for fast‐charge battery applications. Theoretical capacity calculations show that B‐BP outperforms graphite as the commercial case of anode material, with calculated values of 560.67 mAh g−1 for Li and 934.45 mAh g−1 for Na storage.

High-efficiency n-TOPCon cells ensured by an emitter preparation process without post-oxidation

Laser-enhanced contact optimisation (LECO) technology can effectively improve the efficiency of tunnel oxide passivated contact (n-TOPCon) solar cells. Generally, the preparation of an emitter in TOPCon cells requires post-oxidation treatment at temperatures exceeding 1030 °C for over 3000 s. This high-temperature post-oxidation process results in reduced surface doping concentration, increased reflectivity of the front of the cell and elevated manufacturing costs of the junction. In this study, through process research, we reveal that the optimal profile depth of emitter (the boron doping concentration at 1 × 1018 atoms/cm3) for mass-produced LECO pastes ranges from 0.44 to 0.52 μm. Additionally, it was discovered that a boron-rich layer (BRL) thinner than 10 nm does not reduce bulk lifetime and increase contact resistivity. Based on these findings, we developed a boron-diffusion method without post-oxidation, which involves controlling the BRL thickness by adjusting the pre-oxidation layer thickness and cycle deposition. When applied to the mass production of n-TOPCon solar cells, this approach resulted in a solar cell conversion efficiency of 26.28 %. This represents an improvement of 0.03 %–0.05 % over traditional boron-diffusion processes. Furthermore, eliminating post-oxidation significantly improved the production capacity and lifespan of the boron-diffusion furnace, thereby reducing the manufacturing costs associated with the solar cells. Furthermore, eliminating post-oxidation significantly improved the production capacity and lifespan of the boron-diffusion furnace, thereby reducing the manufacturing costs associated with the solar cells.

Correlation of residual stress on piezoresistive properties of boron-doped diamond films

To investigate the influence of residual stress on the piezoresistive behavior of boron-doped diamond (BDD) films, BDD films with varying doping concentrations were synthesized using a hot-filament chemical vapor deposition (HFCVD) system on silicon and diamond substrates. The relationship between the surface morphology, structural composition, resistivity, and piezoresistive properties of BDD electrodes was examined, along with an in-depth analysis of the impact of boron doping level on these properties. The microstructure and bonding state of the BDD films were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. The piezoresistive properties of the BDD films were evaluated employing a cantilever beam bending method. Our findings demonstrate that the level of boron doping not only affects resistivity but also directly influences residual stress in BDD films, both factors having an impact on their piezoresistive properties. Despite significantly larger grain sizes observed in BDD films grown on diamond substrates compared to those grown on silicon substrates at identical boron doping concentrations, they exhibit consistent variations in residual stress and gauge factor (GF) values. With increasing doping levels, the absolute residual stress decreases initially before increasing again; moreover, at 2000 ppm doping level, it transitions from compressive to tensile stress. The GF value is closely associated with both the magnitude and type of residual stress. By utilizing a doping concentration of 2000 ppm for growth on diamond substrates, we achieved a peak GF value of 257 for BDD films which highlights their promising potential for pressure sensor applications.

Regulating Local Electron Distribution of Cu Electrocatalyst via Boron Doping for Boosting Rapid Absorption and Conversion of Nitrate to Ammonia

AbstractThe electrochemical reduction of nitrate to ammonia (NO3RR) is an effective route to ammonia synthesis with the characteristics of low energy input. However, the complex multi‐electron/proton transfer pathways associated with this reaction may trigger the accumulation of competitive by‐products. Herein, boron (B)‐doped Cu electrode (denoted as B–Cu2O/Cu/CP) as “all‐in‐one” catalyst is prepared by one‐step electrodeposition strategy. Caused by the B doping, the charge redistribution and local coordination environment of Cu2O/Cu species are modulated, resulting in the exposure of active sites on the Cu2O/Cu/CP catalyst. In‐situ Fourier transform infrared spectroscopy and theoretical investigations demonstrate that both Cu2O and Cu sites modulated by B can effectively enhance the adsorption of NO3− and facilitate the conversion of intermediate by‐products, thus promoting the direct reduction of NO3− to NH3. Consequently, a remarkable Faradaic efficiency of 92.74% can be obtained on B–Cu2O/Cu/CP catalyst with minimal accumulation of by‐products. It is expected that this work, based on the heterogeneous B doping, will open a maneuverable and versatile way for the design of effective catalysts.

Twisted Structure Induced Solid-State Fluorescence and Room-Temperature Phosphorescence from Furan-Based Carbon Dots.

Boron doping can effectively induce solid-state fluorescence (SSF) in carbon dots (CDs); however, research on the intrinsic mechanism underlying this phenomenon is lacking. Herein, a design strategy for boron-doped furan-based CDs is proposed, CDs with aggregation-induced emission (AIE) properties are synthesized, and the mechanism by which boron atom dopants induces SSF and room-temperature phosphorescence (RTP) is elucidated. The morphology and structural characterization of the CDs indicate that boron doping leads to structural twisting of the CDs. The AIE phenomenon of CDs arises from the inhibition of the twisted structure motions and a reduction in the nonradiative relaxation rate during the aggregation process. In addition, CDs with twisted structures exhibit a smaller overlap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), effectively reducing the singlet-triplet splitting energy (ΔEST). CDs embedded in microcrystalline cellulose (MCC) exhibit green RTP because the nonradiative transitions are suppressed, and the excited triplet species remain stable. For the first time, this study reveals the structure-activity relationship between the twisted structure and optical properties of CDs, providing a new approach for the preparation of solid-state light-emitting CDs.

B-Doped Graphdiynes and Several of Their Corresponding Oxides: A Theoretical Study by X-ray Spectra.

Boron doping can significantly improve the electronic structure and physical and chemical properties of graphdiyne (GDY), which also expands its application prospects in photoelectricity, catalysis, and biology. The accurate configurations characterization of B-doped graphdiyne (B-GDY) has not been achieved due to insufficient experimental and theoretical research. The current work involves the simulation of the geometries of 11 typical B-GDY and B-doped graphdiyne oxides [B(O)-GDY] as well as a pristine GDY, along with their X-ray photoelectron (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra at the density functional theory (DFT) level. The boron and carbon spectra for various bonding types were theoretically imitated to assess the spectral contributions. Calculated outcomes indicate that there is a noticeable dependence of the NEXAFS spectra on the local structure. The simulated XPS spectra provide precise assignments and an extra supplement to the spectra peaks, in addition to the position and general peak forms of simulated spectral peaks matching the experimental spectra fairly well. The combination of XPS and NEXAFS spectra can give useful information for identifying typical B-GDY and B(O)-GDY molecules. This paper offers a comprehensive structure-spectrum relationship of B-GDY and its oxides as well as a further theoretical prediction and guidance for experimental synthesis, which is helpful to solve the challenging issue of identification of B-doped carbon-based materials.