Effect Of Boron Doping Research Articles

Synergistic Effect of Boron Doping and Porous Structures on Titanium Dioxide for Efficient Photocatalytic Nitrate Reduction to Nitrogen in Pure Water.

Photocatalytic reduction of nitrate to N2 holds great significance for environmental governance. However, the selectivity of nitrate reduction to N2 is influenced by sacrificial agents and the kinds of cocatalysts (such as Pt and Ag). The presence of unconsumed sacrificial agents can aggravate environmental pollution, while noble metal-based cocatalysts increase application costs. Herein, the porous boron-doped TiO2 (B-TiO2) was successfully synthesized by using the sol-gel method with Amberlite IRA-900 as a template. The incorporation of 33% boron into TiO2 (33% B-TiO2) achieved a 100% nitrate (20 ppm) conversion rate and 94.5% N2 selectivity without the need for sacrificial agents and cocatalysts during the nitrate reduction process. The catalyst's unique multistage porous structure not only enhances the light absorption ability but also significantly provides abundant surface adsorption sites. Additionally, theoretical studies show that boron doping effectively modulates the band structure of TiO2 and increases the electron density at the Ti surface active sites, both of which are essential for achieving a high nitrate reduction efficiency. This work emphasizes the synergistic effect between morphology control and electronic structure regulation in promoting the photocatalytic reduction of nitrate to nitrogen, providing valuable insights for the photocatalytic treatment of nitrate wastewater.

Chitosan-Based Porous Carbon Materials with Built-In Lewis Acid Boron Sites for Enhanced CO2 Capture and Conversion via an Electron-Inducing Effect.

Electron-induced effects, which are prevalent in adsorption and heterogeneous catalytic reactions, can significantly influence the state and uptake of adsorbates. Here, we demonstrate the in situ doping of electron-deficient boron into the backbone of chitosan-based porous carbon materials. Despite a reduction in specific surface area, the resulting boron-doped porous carbons (NBPCs) exhibit an enhanced CO2 adsorption performance, with sample NBPC-10 achieving CO2 adsorption capacities of 7.62 and 4.82 mmol·g-1 at 273 and 298 K, respectively. This improvement is attributed to the electron-induced effect of boron doping, which also enhances the separation selectivity of CO2 from N2. Additionally, the high CO2 adsorption capacity fosters synergism between NBPCs and the cocatalyst tetrabutylammonium bromide (TBAB), thereby augmenting the catalytic activity for the cycloaddition of CO2 and epoxide. Notably, cyclic carbonate yields exceeding 99% were attained even under 1 bar of CO2. Controlled experiments corroborated the pivotal role of boron-doping-induced modifications in the porous carbon structure in enhancing both CO2 selective adsorption and conversion performance. Furthermore, NBPCs demonstrated excellent recyclability as both adsorbents and catalysts, offering fresh perspectives for the design of functionalized porous carbon materials tailored for CO2 capture and conversion.

Intervalence plasmons in boron-doped diamond

Doped semiconductors can exhibit metallic-like properties ranging from superconductivity to tunable localized surface plasmon resonances. Diamond is a wide-bandgap semiconductor that is rendered electronically active by incorporating a hole dopant, boron. While the effects of boron doping on the electronic band structure of diamond are well-studied, any link between charge carriers and plasmons has never been shown. Here, we report intervalence plasmons in boron-doped diamond, defined as collective electronic excitations between the valence subbands, opened up by the presence of holes. Evidence for these low-energy excitations is provided by valence electron energy loss spectroscopy and near-field infrared spectroscopy. The measured spectra are subsequently reproduced by first-principles calculations based on the contribution of intervalence band transitions to the dielectric function. Our calculations also reveal that the real part of the dielectric function exhibits a crossover characteristic of metallicity. These results suggest a new mechanism for inducing plasmon-like behavior in doped semiconductors, and the possibility of attaining such properties in diamond, a key emerging material for quantum information technologies.

Roles of doping in enhancing the performance of graphene/graphene-like semiconductors

Graphene is renowned for its excellent chemical, thermal, mechanical, electrical, and optical properties, which arise from its unique bonding structure. However, graphene is intrinsically a zero-bandgap material, limiting its development in the field of flexible nanoelectronics. To expand the range of applications for graphene in electronic devices, it is crucial to develop the strategies for inducing a bandgap. One of the most effective methods is chemical doping. Doping not only alters the electronic properties of graphene by modifying its inherent gapless nature but also engenders new materials with distinctive and potentially synergistic characteristics. Although there are many reviews on the doped graphene, there is a rare one to discuss the role of doping in enhancing the performance of graphene-based semiconductors. This paper reviews various doping types and their impacts on graphene, emphasizing the effects of boron (B) doping, nitrogen (N) doping, oxygen-group doping, other non-metallic atom or atomic pair doping, and metallic doping. We will further discuss how these dopants affect the geometry, electronic structure, and mechanical properties of graphene. It is expected to be meaningful for further understanding the nature of doped graphene and building new graphene-like structures.

The Effect of Silicon and Boron Doping on the Microstructure of Arc Melted Boron Carbide

The Effect of Silicon and Boron Doping on the Microstructure of Arc Melted Boron Carbide

Boron doping induced manganese oxide local metallicity for optimising intrinsic conductivity and supercapacitor performance

Poor electrical conductivity, a crucial issue in applying manganese oxides as electronic materials, has been mentioned in nearly all related research work. A universal optimization scheme for intrinsic conductivity is lacking among solutions. In this study, boron with a strong Lewis acidity was selected as a doping source to modulate the electronic structure of manganese oxide. Boron, a commonly-used p-type doping element, has an unclear doping mechanism for transition metal oxides. Based on the first principles, all doping possibilities were investigated, finding boron atoms can most easily enter the lattice interstice. Importantly, after boron atom doping, the material generates a density of state at the Fermi level, resulting in the overlap of the valence and conduction band, forming a partial occupation band. The material changes from semiconductor properties to metallic properties and the electrical conductivity is significantly optimized. To verify the scheme feasibility, boron-doped Mn3O4 was synthesized through the hydrothermal and the charge transfer resistance of sample Mn-B-4 is 46 % lower than that of undoped Mn3O4 electrodes. Further exploration of boron doping effects was conducted by using supercapacitor tests which are strongly influenced by conductivity. Mn-B-4 exhibited better rate performance and cyclic stability as a supercapacitor electrode. The positive effects of boron doping on the electrical conductivity of manganese oxides were demonstrated through both theoretical calculations and experiments. This study will provide a general solution reference for large-scale modification and application of manganese oxide and would contribute to the promotion of the related electronic materials field.

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.

Effect of boron doping on the irradiation resistance of iron phosphate glass: Insights from mechanical properties and chemical stability

We investigated the ion-irradiation effects of iron phosphate glasses (IPGs) with composition of 40Fe2O3‒60P2O5 (mol%) and 10B2O3‒36Fe2O3‒54P2O5 (mol%), respectively, and explored the effect of boron doping on the mechanical properties and the chemical stability. Mono-ion irradiation (5-MeV Xe20+) and sequential irradiation scenario (5-MeV Xe20++ 250-keV H+) were performed with different doses. As the Xe-dose increased, both the hardness and the Young's modulus decreased until converging to saturation, and then the hardness tended to recover. The variations in mechanical properties and water contact angle of the 10B2O3‒36Fe2O3‒54P2O5 were more significant than those of the 40Fe2O3‒60P2O5, indicating inferior irradiation resistance. The hardness recovery was also observed in H-ion irradiation whose energy deposition is predominated by electronic interaction, while the boron doping weakened this phenomenon. Our study contributes to understanding the long-term behavior of IPG during the underground disposal of high-level waste, and provides fundamental data to optimize the design of IPG formulations.

Performance improvement strategies of boron-doped lithium-rich layered oxide cathode materials for wide temperature condition

Herein, the boron-doped Li-rich materials are prepared by rapid nucleation-assisted solvothermal and high-temperature method. In this work, the effects of boron doping on crystal structure and cycling performances of as-prepared materials were investigated. The material characterization results show that the introduction of B reduces the TM valence, enlarges the (003) space distance, and modulates the local crystal structure, which may change the electrochemical performance of as-prepared samples. Li1.2Ni0.24Co0.08Mn0.48B0.02O2 (LLNCMBO-2) showed an increase in discharge capacity of 36.5 mAh g−1 at 0.1 C compared to the pristine sample. The LLNCMBO-2 exhibit high capacity retention of 85.50 % after 200 cycles with a voltage decay of only 254.9 mV. Additionally, the results of wide temperature testing show that the electrochemical performance of boron-doped samples improved evidently.

Multi boron-doping effects in hard carbon toward enhanced sodium ion storage

Hard carbon (HC) has been considered as promising anode material for sodium-ion batteries (SIBs). The optimization of hard carbon’s microstructure and solid electrolyte interface (SEI) property are demonstrated effective in enhancing the Na+ storage capability, however, a one-step regulation strategy to achieve simultaneous multi-scale structures optimization is highly desirable. Herein, we have systematically investigated the effects of boron doping on hard carbon’s microstructure and interface chemistry. A variety of structure characterizations show that appropriate amount of boron doping can increase the size of closed pores via rearrangement of carbon layers with improved graphitization degree, which provides more Na+ storage sites. In-situ Fourier transform infrared spectroscopy/electrochemical impedance spectroscopy (FTIR/EIS) and X-ray photoelectron spectroscopy (XPS) analysis demonstrate the presence of more BC3 and less B–C–O structures that result in enhanced ion diffusion kinetics and the formation of inorganic rich and robust SEI, which leads to facilitated charge transfer and excellent rate performance. As a result, the hard carbon anode with optimized boron doping content exhibits enhanced rate and cycling performance. In general, this work unravels the critical role of boron doping in optimizing the pore structure, interface chemistry and diffusion kinetics of hard carbon, which enables rational design of sodium-ion battery anode with enhanced Na+ storage performance.

Thermal stabilization enhancement of diamond films via boron doping and its antioxidant mechanism

Diamond films possess numerous extraordinary physical and chemical properties, but their high-temperature applications are limited by its poor thermal stability. Herein, we fabricated the undoped microcrystalline diamond (MCD) film and heavy boron-doped diamond (h-BDD-1, 2.94 × 1021 atoms·cm−3; h-BDD-2, 9.10 × 1021 atoms·cm−3) films to investigate the effect of boron doping on the thermal stability of diamond films. A series of evidences, including air annealing experiments, thermogravimetric-differential scanning calorimetry (TG-DSC) analysis, and in-situ ultra-high-temperature confocal laser-scanning microscope (CLSM), demonstrated that the thermal stability of diamond films was obviously enhanced by boron doping. Consequently, the h-BDD-2 film exhibited the best thermal stability with an initial oxidation temperature above 900 °C, which was much higher than that of MCD film (709 °C). By deconvolving the X-ray photoelectron spectra, we believed that the transition of B–C bonds to stable oxy-boron carbide complexes (B4O–C, B3O–C) is the key to improving the thermal stability. These results not only reveal a new antioxidant mechanism of boron-doped diamond films but also pave a way for the application of diamond in high-temperature environments.

Effects of boron doping on the surface modification and defect evolution of silicon induced by proton implantation and annealing

Ultra-thin silicons can be obtained using SMART CUT technology, but there is a lack of systematic research on the effect of boron doping. This paper reports the effects of boron doping on surface modification and defect evolution. Monocrystalline silicon samples with different concentrations of boron doping were implanted to 3.5 × 1017H+/cm2 using a 1.52 MeV High Intensity Proton Implanter (HIPI) and annealed at 300, 400, and 550 ℃. The annealed samples were analyzed by non-contact optical profilometry, Raman spectroscopy, SEM, and TEM. The results show that appropriate boron doping can reduce the surface roughness of the exfoliated samples; excessive boron doping leads to a significant increase in surface roughness (∼525 nm) and produces a step-like morphology. Boron doping leads to changes in the type, concentration and dissociation temperature of hydrogenated defects during implantation. These changes result in the width of damage band changes vary with doping concentration. The density and diameter of the hydrogenated extended defects also changed, which results in the surface modification of samples, such as the change of the surface morphology and substrate roughness. In the end of the paper, the paper discusses the correlation between surface morphology and internal damage for different concentrations of boron doping.

Effects of boron doping in InSe single crystals on optical limiting performance in the near-infrared region

Identification of photonic materials with high infrared transmittance and high nonlinear optical coefficients is one of the main emphases in material science as a result of the rapid advancement in infrared photonics. In this study, undoped and B (boron) -doped InSe single crystals were grown by using the modified vertical Bridgman method, and their nonlinear optical properties were investigated to reveal their usability as an optical limiter in the near-infrared region. The decreasing band gap energies and increasing defect states were determined with increasing B concentration in InSe single crystals. The effect of the B concentration on the nonlinear absorption (NA) and optical limiting properties of the InSe single crystals was investigated via open aperture (OA) Z-scan experiments under ultrafast laser excitation at 1200 nm wavelength with 100 femtosecond pulse duration. Two-photon absorption (TPA) was the dominant NA mechanism at 1200 nm excitation wavelength in the femtosecond domain. The results revealed that the NA became stronger with increasing input intensity and increasing amount of B dopant atoms in the InSe single crystal. The observed enhanced NA can be attributed to two possible events (i) increasing input intensity induced more excited electrons which led to more contribution to NA through TPA and (ii) increasing B dopant atoms in InSe single crystal induced more defect states. The NA may be more enhanced with the contribution of these defect states related NA mechanisms. The high transparency and strong NA behavior at the near-infrared region make these single crystals exceptional potential candidates for developing various optoelectronics and filters at the near-infrared spectral region.

Increasing the Catalytic Activity of Co3O4 via Boron Doping and Chemical Reduction for Enhanced Acetone Detection

AbstractOptimally increasing the catalytic activity of Co3O4‐based materials is crucial for promoting their practical applications for acetone detection; however, this still remains challenging. Herein, a strategy is proposed in this work to increase the catalytic activity of Co3O4 toward the oxidation of acetone through the synergistic effect of boron doping and chemical reduction, which can substantially improve the sensing performance for acetone detection. The characterization results confirm that the present strategy facilitates the formation of more oxygen vacancies and increases the content of Co2+ ions serving as active sites. As expected, the optimal sensor yields a higher response . To extend the practical application to the auxiliary diagnosis of diabetes through exhaled breath, the optimal sensors distinguished between acetone concentrations in the breath of healthy individuals and in the simulated breath of patients with diabetes. Detailed gas‐sensing measurements reveal that the enhanced acetone sensing performance is attributed to the increased catalytic activity of materials for oxidation of acetone by the Mars–van Krevelen, Langmuir–Hinshelwood, and Eley–Rideal mechanisms. This study provides new insights into the fabrication of high‐performance metal oxide‐based gas sensors by improving the catalytic activity of sensing materials.

Synthesis and investigation of novel boron- and magnesium-doped YAG:Ce and LuAG:Ce phosphor ceramics.

YAG:Ce and LuAG:Ce ceramics are widely used as scintillator materials that convert high-energy radiation into visible light. For the practical application of such compounds, short decay times are a necessity. One way of shortening the existing decay times even more is to change the local environment of emitting ions by means of doping the matrix with additional elements, for example, boron or magnesium. Furthermore, boron ions also can help absorb gamma rays more efficiently, therefore improving overall applicability. Due to the aforementioned reasons, YAG and LuAG ceramics doped with cerium, boron, and magnesium were synthesized. Initial amorphous powders have been obtained by means of sol-gel synthesis and pressed into pellets under isostatic pressure and finally calcinated to form crystalline ceramics. The effects of boron and magnesium doping on the morphological, structural, and luminescence properties were investigated. The key results showed that doping with boron has indeed shortened the decay times of the garnet pellets. Overall, boron doping of ceramics is a relatively new research area; however, it is rather promising as it helps both to improve the luminescence properties and to increase particle growth rate.

The impact of boron doping in the tunneling magnetoresistance of Heusler alloy Co2FeAl

Heusler alloy-based magnetic tunnel junctions have the potential to provide high spin polarization, small damping, and fast switching. In this study, junctions with a ferromagnetic electrode of Co2FeAl were fabricated via room-temperature sputtering on Si/SiO2 substrates. The effect of boron doping on Co2FeAl magnetic tunnel junctions was investigated for different boron concentrations. The surface roughness determined by atomic force microscope, and the analysis of x-ray diffraction measurement on the Co2FeAl thin film reveals critical information about the interface. The Co2FeAl layer was deposited on the bottom and on the top of the insulating MgO layer as two different sample structures to compare the impact of the boron doping on different layers through tunneling magnetoresistance measurements. The doping of boron in Co2FeAl had a large positive impact on the structural and magneto-transport properties of the junctions, with reduced interfacial roughness and substantial improvement in tunneling magnetoresistance. In samples annealed at low temperature, a two-level magnetoresistance was also observed. This is believed to be related to the memristive effect of the tunnel barrier. The findings of this study have practical uses for the design and fabrication of magnetic tunnel junctions with improved magneto-transport properties.

Experimental and computational analysis of stacking fault energy in B-doped Fe50−XMn30Co10Cr10BX multi-principal elements alloys

The effect of boron doping in Fe50−XMn30Co10Cr10BX multi-component alloys on the resulting stacking fault energy has been experimentally and computationally assessed to understand the alloys' deformation mechanisms from structural and thermodynamic perspectives. Firstly, the fcc and hcp phases were identified together with stacking faults along their (110) planes using high-resolution transmission electron microscopy. At the same time, they were theoretically predicted through thermodynamic CALPHAD and ab initio calculations. The average stacking fault energy for the boron-free alloy was 23.9 ± 2.4 mJ/m2, suggesting that the deformation mechanisms relate to dislocation slip and deformation twinning. The average stacking fault energy for the highest boron content (5.4 at%) was 50.1 ± 14.1 mJ/m2, indicating dislocation glide as the possible deformation mechanism. The boron content in the solid solution was modelled. The modelling suggested that the presence of Cr-B, Mn-B and Fe-B bonds points towards forming (Cr,Fe)2B borides, which was experimentally confirmed. The borides, fcc phase stability, and the boron in solid solution contribute to increased stacking fault energy, preventing the motion of Shockley partial dislocations and influencing the ɛ-hcp martensitic transformation.

The effect of boron and scandium doping on the luminescence of LuAG:Ce and GdAG:Ce for application as scintillators

This study concerns cerium and boron doped Lu3Al4Sc1O12 and Gd3Al3Sc2O12 garnet µ-crystalline powders, which were synthesized for the first time. Rare earth ion, particularly Ce3+ activated garnets, due to their high density and efficient Ce3+ luminescence upon blue, UV, or x-ray excitation, can be used as scintillators that convert high-energy radiation into visible light. The incorporation of B3+ and Sc3+ ions into the garnet matrix corresponds to the improvement of the scintillating properties. Boron in these compounds could act like a flux and thus modulate particle morphology, while scandium solely changes the physical and luminescent properties of these garnets. From the measured radioluminescence emission spectra, it could be concluded that boron doping results in a higher emission intensity when the compounds are excited by high-energy radiation. The most striking effect is that the decay time is reduced, and the quantum efficiency of the compounds increases. After improving the kinetic properties of these compounds, it is possible to discuss a wider application of the synthesized materials. In addition to the aforementioned properties, room temperature as well as temperature dependent photoluminescence emission, excitation, and decay times at different temperatures were taken for all samples. The elemental composition of the samples was determined by using the ICP-OES technique. The crystal structure was analyzed by means of powder XRD. Particle morphology and size distribution were also investigated.The main idea of this research is to synthesize new and adjusted garnet type compounds that show better luminescent properties, which are required for scintillator materials.

Electronic and transport properties of boron and nitrogen doped germanene nanoribbons: A first principles study

We have studied the electronic properties of pristine zigzag germanene nanoribbons (ZGeNRs) using ab initio method. The effect of boron and nitrogen doping on electronic properties of ZGeNRs at two different edge sites is also calculated. It is observed that the H-terminated pristine ZGeNRs exhibit semi-metallic behavior while the ZGeNRs doped with boron and nitrogen shows the metallic behavior. The electron density calculation shows that the density is low in pristine ZGeNRs while it is high in the doped ZGeNRs. The transmission coefficient analysis also suggests the same. As the transmission is sensitive to doping, hence, ZGeNRs have potential application in nanoelectronics devices.

Cyclo[18]carbon as a Hazardous Gas Scavenger: Effect of Boron and Nitrogen Doping on Molecular Adsorption

AbstractDoping is one of the most important mechanisms to enhance the molecular adsorption performance of bulk and nanostructures. Here, we have investigated the adsorption performance of Boron and Nitrogen doped C18 nanocluster (or C17X : X=B,N) towards the gases CO, NO and NH3 by means of first principles calculations. The structural, electronic, and sensing properties of C17X nanoclusters are studied to understand their sensing behavior, using gaussian 09 package. The interaction of C17B nanocluster with CO, NO and NH3 molecules results into chemical adsorption with order of adsorption energies as: CO (−1.41 eV)>NH3 (−1.81 eV)>NO (−2 eV). However, in case of C17N, the interaction with CO and NH3 results into physisorption, and chemisorption is observed only for its interaction with NO gas molecule. The adsorption energy order goes as: CO (−0.15 eV)>NH3 (−0.25 eV)>NO (−1.32 eV). The long recovery time in case of C17B nanocluster after the adsorption, makes it suitable for removal application, whereas shorter recovery time (in case of C17N nanocluster for CO and NH3 adsorption), is suitable for sensor application.