Boride Nanosheets Research Articles

Interlayer Hydrogen Recombination from Hydrogen Boride Nanosheets Elucidated by Isotope Labeling.

In this study, deuterium boride (DB) nanosheets were synthesized as deuterated borophane through the ion exchange of magnesium cations in magnesium diboride with deuterons from a deuterium-type ion-exchange resin in acetonitrile. The Fourier-transform infrared absorption spectrum of DB exhibited clear isotope effects, namely the shift in the absorption peak of the B-H stretching vibrational mode to a lower wavenumber. Temperature-programmed desorption (TPD) from a mixture of DB and hydrogen boride (HB) nanosheets yielded a more intense hydrogen-deuterium (HD) signal compared to the H2 and D2 signals. This indicates that the release of hydrogen molecules from the HB nanosheets upon heating originated from interlayer hydrogen recombination rather than intralayer hydrogen recombination. TPD analysis of HB with graphene in different mixing ratios confirmed that the interlayer reaction is predominant in the lower-temperature (<623 K) regime. Meanwhile, the intralayer reaction could proceed in the higher-temperature (>623 K) regime, where hydrogen recombination occurs following H migration on the HB nanosheets.

Titanium boride nanosheets with photo-enhanced sonodynamic efficiency for glioblastoma treatment

Sonodynamic therapy (SDT) has garnered significant attention in cancer treatment, however, the low-yield reactive oxygen species (ROS) generation from sonosensitizers remains a major challenge. In this study, titanium boride nanosheets (TiB2 NSs) with photo-enhanced sonodynamic efficiency was fabricated for SDT of glioblastoma (GBM). Compared with commonly-used TiO2 nanoparticles, the obtained TiB2 NSs exhibited much higher ROS generation efficiency under ultrasound (US) irradiation due to their narrower band gap (2.50 eV). Importantly, TiB2 NSs displayed strong localized surface plasmon resonance (LSPR) effect in the second near-infrared (NIR II) window, which facilitated charge transfer rate and improved the separation efficiency of US-triggered electron–hole pairs, leading to photo-enhanced ROS generation efficiency. Furthermore, TiB2 NSs were encapsulated with macrophage cell membranes (CM) and then modified with RGD peptide to construct biomimetic nanoagents (TiB2@CM-RGD) for efficient blood-brain barrier (BBB) penetrating and GBM targeting. After intravenous injection into the tumor-bearing mouse, TiB2@CM-RGD can efficiently cross BBB and accumulate in the tumor sites. The tumor growth was significantly inhibited under simultaneous NIR II laser and US irradiation without causing appreciable long-term toxicity. Our work highlighted a new type of multifunctional titanium-based sonosensitizer with photo-enhanced sonodynamic efficiency for GBM treatment. Statement of significanceTitanium boride nanosheets (TiB2 NSs) with photo-enhanced sonodynamic efficiency was fabricated for SDT of glioblastoma (GBM). The obtained TiB2 NSs displayed strong localized surface plasmon resonance (LSPR) effect in the second near-infrared (NIR II) window, which facilitated charge transfer rate and improved the separation efficiency of US-triggered electron-hole pairs, leading to photo-enhanced ROS generation efficiency. Furthermore, TiB2 NSs were encapsulated with macrophage cell membranes (CM) and then modified with RGD peptide to construct biomimetic nanoagents (TiB2@CM-RGD) for efficient blood-brain barrier (BBB) penetrating and GBM targeting. After intravenous injection into the tumor-bearing mouse, TiB2@CM-RGD can efficiently cross BBB and accumulate in the tumor sites. The tumor growth was significantly inhibited under simultaneous NIR II laser and US irradiation without causing appreciable long-term toxicity.

Visible-Light-Induced Hydrogen Generation from Mixtures of Hydrogen Boride Nanosheets and Phenanthroline Molecules.

Hydrogen boride (HB) nanosheets are recognized as a safe and lightweight hydrogen carrier, yet their hydrogen (H2) generation technique has been limited. In the present study, nitrogen-containing organic heterocycles are mixed with HB nanosheets in acetonitrile solution for visible-light-driven H2 generation. After exploring various nitrogen-containing heterocycles, the mixture of 1,10-phenanthroline molecules (Phens) and HB nanosheets exhibited significant H2 generation even under visible light irradiation. The quantum efficiency for H2 generation of the mixture of HB nanosheets and Phens is 0.6%. Based on spectroscopic and electrochemical analyses and density functional theory (DFT) calculations, it is determined that radical species generated from Phens with electrons and protons donated by HB nanosheets are responsive to visible light for H2 generation. The HB nanosheets/Phens mixture presented in this study can generate H2 using renewable energy sources such as sunlight without the need for complex electrochemical systems or heating mechanisms and is expected to serve as a lightweight hydrogen storage/release system.

Novel two-dimensional FeB nanosheets for photoacoustic imaging-guided NIR-photothermal therapy

The development of biosafe near infrared (NIR)-photothermal nanomaterials is meaningful for tumor-targeted photothermal therapy and photoacoustic imaging for high-performance theranostics, but still challenging. Herein, we propose a new ultrasound-assisted chemical etching method based on the Fenton reaction to synthesize a novel kind of two-dimensional iron boride nanosheets (FBN) as NIR-photothermal nanomaterials. The developed FBN theranostic agent exhibits high NIR adsorption and NIR-photothermal conversion efficiencies, realizing biosafe and high efficacy of photoacoustic imaging-guided tumor-targeted NIR-photothermal therapy of tumor mice.

Visible-Light-Driven Hydrogen Release from Dye-Sensitized Hydrogen Boride Nanosheets.

Hydrogen boride (HB) nanosheets are expected to be safe and lightweight hydrogen carriers because of their high gravimetric hydrogen density (8.5 wt %) and photon-driven hydrogen release under mild conditions. However, previously reported HB nanosheets respond only to ultraviolet (UV) light to release hydrogen. In this study, we develop dye-modified HB nanosheets that can release hydrogen under visible light irradiation (>470 nm) without heat input. Hydrogen generation is initiated by electron injection from excited dye molecules into the conduction band of the HB nanosheets. The conduction band of the HB nanosheets is formed by the antibonding states of the B 2py and H 1s atomic orbitals, and the electrons injected from the dye molecules react with the protons of the HB nanosheets to release gaseous hydrogen molecules. Although the hydrogen production is terminated after long-term light irradiation owing to dye oxidation and/or loss of protons in HB nanosheets, the total amount of the released hydrogen molecules corresponds to approximately 25% of the protons in HB nanosheets even under the extra mild conditions. The addition of a sacrificial agent like iodine ions and a proton source like formic acid sustained the H2 generation from the dye-modified HB nanosheets under visible light irradiation for long term.

2D Tungsten Borides Induced Interfacial Modulation Engineering Toward High-Rate Performance Zinc-Iodine Battery.

Aqueous zinc-iodine batteries are promising candidates for large-scale energy storage due to their high energy density and low cost. However, their development is hindered by several drawbacks, including zinc dendrites, anode corrosion, and the shuttle of polyiodides. Here, the design of 2D-shaped tungsten boride nanosheets with abundant borophene subunits-based active sites is reported to guide the (002) plane-dominated deposition of zinc while suppressing side reactions, which facilitates interfacial nucleation and uniform growth of zinc. Meanwhile, the interfacial d-band orbits of tungsten sites can further enhance the anchoring of polyiodides on the surface, to promote the electrocatalytic redox conversion of iodine. The resulting tungsten boride-based I2 cathodes in zinc-iodine cells exhibit impressive cyclic stability after 5000 cycles at 50 C, which accelerates the practical applications of zinc-iodine batteries.

Regulating the crystallinity and hydrophobicity of cobalt boride nanosheet for enhanced CO2 photoreduction performance

Developing low-cost and efficient cocatalysts to strengthen CO2 conversion using solar energy is of great importance to reduce reliance on fossil fuels. Two-dimensional cobalt boride (CoB) nanosheets with comparatively high work function and low ΔGH* are prone to undergo low crystallinity under rigorous synthetic conditions. Herein, a facile method of thermal-induced molten salt melt is used to regulate the structure characters of CoB nanosheets. The optimized CoB cocatalyst as a noble-metal-free cocatalyst delivers a high CO formation rate of 29.6 μmol h−1 and selectivity of 70.1 % with visible light irradiation. This elevation is steered by the promoted crystallinity and hydrophobicity, which can speed the charge kinetics and reduce the proton accumulation on the surface as evidenced by various photoelectrochemical tests and contact angle tests of water, respectively. The high CO2 adsorption based on alkaline Co atoms of the CoB nanosheets drives the key COOH* intermediates production analyzed by the in-suit infrared spectra. This work exploits newly Co-based cocatalysts and strengthens the structure–activity relationship for efficient CO2 photoconversion.

Injectable spontaneous hydrogen-releasing hydrogel for long-lasting alleviation of osteoarthritis.

Excessive production of reactive oxygen species (ROS) amplifies pro-inflammatory pathways and exacerbates immune responses, and is a key factor in the progression of osteoarthritis (OA). Therapeutic hydrogen gas (H2) with antioxidative and anti-inflammatory effects, has a potential for OA alleviation, but the targeted delivery and sustained release of H2 are still challenging. Herein, we develop an injectable calcium boride nanosheets (CBN) loaded hydrogel platform (CBN@GelDA hydrogel) as a high-payload and sustainable H2 precursor for OA treatment. The CBN@GelDA hydrogel could maintain constant physiological pH conditions which further promotes more H2 release than the CBN alone and lasts more than one week. The biocompatibility of this hydrogel with macrophages and chondrocytes is effectively enhanced. The experiments show that the CBN@GelDA hydrogel holds the ROS scavenging ability, reducing the expression of related inflammatory cytokines, lessening M1 macrophages but stimulating M2 phenotype, and thereby decreasing chondrocyte apoptosis, which facilitates to breaking of the vicious circle of OA progression. Furthermore, a single-time injection of the CBN@GelDA hydrogel markedly reduces joint destruction in OA rats. From what has been discussed above, this injectable spontaneous H2-releasing hydrogel is promising for OA treatment. STATEMENT OF SIGNIFICANCE: Oxidative stress and inflammation play the key role in the occurrence and development of osteoarthritis (OA). The system of a hydrogel loaded with H2 precursor calcium boride nanosheet (CBN), which is the first to use as an H2 precursor, integrates superior injectable and biocompatible of hydrogel and the selection of antioxidant properties of H2. This system can improve H2 release behavior and achieve a single injection into the articular cavity to alleviate the progression of OA in rats. This study of the combination of a convenient long-acting injectable hydrogel and a safe therapeutic gas is of great value for improving the quality of life of clinical patients.

Interfacial electronic heterostructure engineering of cobalt boride nanosheets toward broadband efficient electromagnetic absorption

Vigorous reflection loss (RL), wide bandwidth together with suitable absorption frequency band are key application indicators for cutting-edge electromagnetic (EM) absorbers to avoid EM pollution in the aerospace. However, the rational design of EM absorbers, especially for the integration of multiple properties, remains highly challenging. Here, we report a novel two-dimensional (2D) nanosheets-like heterostructure constructed by a molten salt-assisted dissolution-growth strategy and linked via strong interfacial electronic interactions, namely, cobalt boride (CoB) with boron, nitrogen co-doped carbon (CoB/BNC). Density functional theory (DFT) calculations demonstrate that stable heterointerfaces formed by strong interfacial electronic interactions are beneficial for enriching polarization effects, while contributing sufficient dielectric loss to boost the EM absorption (EMA) performance. Accordingly, the minimum RL (RLmin) of −70.76 dB and effective absorption bandwidth (EAB) of 4.72 GHz are simultaneously accomplished for CoB/BNC at the thickness of 3.48 mm. Moreover, radar cross section (RCS) simulation results confirmed that the as-prepared absorber coating could perfectly suppress the metal scattering sources in different directions. Generally, this work offers an ingenious engineering strategy for the precise synthesis of functional heterostructures, which holds great promise for developing innovative EMA materials in the aerospace.

Application of transition metal boride nanosheet as sulfur host in high loading Li-S batteries

Two-dimensional (2D) metal boride material (MBene) has aroused concern recently. However, the research and application exploration for MBene materials with more exposure sites are seriously restricted due to lack of suitable preparation methods. Herein, a kind of composites of monolayer MBene nanosheets and carbon nanotube (mono-MBene/CNT) is prepared through ice template method for the first time and applicated as a novel cathode host in high-loading lithium-sulfur (Li-S) batteries. Benefiting from multifunctional advantages of mono-MBene/CNT cathode including anchoring lithium polysulfides (LiPS), multiple functional sites and fast lithium-ion transport, the cells with S@mono-MBene/CNT cathode exhibit superior long-term cycling performance over 1000 cycles. Most notably, even if the sulfur loading is up to 15.28 mg cm−2, the cells with S@mono-MBene/CNT cathode deliver an initial area capacity of 12.73 mAh cm−2 and the capacity can also maintain at 11.07 mAh cm−2 after 120 cycles (86.96 % capacity retention) with current density of 21.80 mA cm−2, which is approximately 3 times higher than the capacity of commercial lithium-ion batteries. This work not only provides a guiding role in preparing monolayer MBene material, but also exhibits the application prospect for MBene material in the fields of energy storage.

High electrochemical activity of Li2S2 linking two-dimensional tungsten boride nanosheet enables high-loading and long-lasting lithium-sulfur batteries

The Li2S-based cathodes with a high theoretical capacity of 1,166 mAh/g are regarded as the commercially available lithium-sulfur battery that can be coupled with Li-free anodes to avoid the safety concern of lithium metal. However, the instinct Li2S passivation leads to a high activation potential and low sulfur utilization with the notorious polysulfide migration. Herein, the single-atom tailoring strategy in designing liquid Li2S2 catholyte is created without the use of any complicated manufacturing processes or additives, where the Li2S2 cell enables the 3.0 V activation voltage without potential barrier. Meanwhile, the conductive and polar tungsten boride offer the active center to anchor polysulfides migration. As expected, the tungsten boride-Li2S2 cathode exhibits excellent cycling stability, impressive cycling performance without initial potential barrier.

Exploring the biotoxicity of carbon boride nanosheets (BC3) based on the villin headpiece protein model

The recently synthesized single-layer carbon boride (BC3), has been explored for biomedical applications. However, the interaction between BC3 and biomolecules needs to be further explored to evaluate its potential toxicity to biological systems. Here, using the villin headpiece (HP35) as a representative protein model, the binding behavior of proteins to BC3 and the structure evolution of proteins were studied by molecular dynamics simulation. Our data revealed that HP35 can quickly load and form stable binding to BC3 surface. The BC3 caused moderate destruction of the HP35 by destroying its native hydrogen bonds and unwinding its helices. The BC3/HP35 interaction strength is linearly correlated with the contact number between BC3 and HP35. HP35 forms binds to BC3 mainly through van der Waals interactions and π-π stacking. Compared to graphene, the polarized nature of BC3 can slightly strengthen the binding between BC3 and HP35. BC3 still faces the problem of potential cytotoxicity to biological system. These findings shed light on the biological effects of BC3 at the molecular level and guide the future application of BC3-based devices in biomedicine.

Synergistic Incorporation of Fe and Co into Nickel Boride Nanosheets to Tune Voltage Plateau and Charge Storage in Supercapacitors

Synergistic Incorporation of Fe and Co into Nickel Boride Nanosheets to Tune Voltage Plateau and Charge Storage in Supercapacitors

Synergistic Incorporation of Fe and Co into Nickel Boride Nanosheets to Tune Voltage Plateau and Charge Storage in Supercapacitors

Synergistic Incorporation of Fe and Co into Nickel Boride Nanosheets to Tune Voltage Plateau and Charge Storage in Supercapacitors

Chemical stability of hydrogen boride nanosheets in water

Boron-based two-dimensional materials are of interest for use in electronic devices and catalytic applications, for which it is important that they are chemically stable. Here, we explore the chemical stability of hydrogen boride nanosheets in water. Experiments reveal that mixing hydrogen boride and water produces negligible amounts of hydrogen, suggesting that hydrolysis does not occur and that hydrogen boride is stable in water, which is in contrast to most boron hydride materials. First-principles calculations reveal that the sheets interact weakly with water even in the presence of defects and that negatively charged boron prevents the onset of hydrolysis. We conclude that the charge state of boron and the covalent boron-boron bond network are responsible for the chemical and structural stability. On the other hand, we found that proton exchange with hydrogen boride nanosheets does occur in water, indicating that they become acidic in the presence of water.

MBene as a Theranostic Nanoplatform for Photocontrolled Intratumoral Retention and Drug Release.

Tumor-targeted drug delivery by nanomaterials is important to improve tumor therapy efficacy and reduce toxic side effects, but its efficiency is quite limited. In this work, a new type of MBene, zirconium boride nanosheet (ZBN), as a versatile nanoplatform to realize near-infrared (NIR)-controlled intratumoral retention and drug release is developed. ZBN exhibits high NIR-photothermal conversion efficiency (76.8%), surface modification with hyaluronic acid (HA) by polyol-borate esterfication endows ZBN-HA with good dispersion, and the photopyrolysis of borate ester causes HA detachment and ZBN aggregation, enabling NIR-controlled intratumoral retention to achieve high intratumoral accumulation. By virtue of surface borate esterfication, polyol chemotherapeutic drug (doxorubicin, DOX), and NO prodrug (β-galactosyl-diazeniumdiolate, Gal-NO) can be efficiently and stably conjugated on the surface of ZBN-HA (1.21g DOX or 0.57g Gal-NO per gram ZBN) without visible drug leakage, and the photopyrolysis of borate ester enables NIR-controlled drug release with high responsiveness and controllability. Combined chemothermal/gasothermal therapies based on ZBN-HA/DOX and ZBN-HA/NO nanomedicines eradicate primary tumors and interdict tumor metastasis by changing the tumor microenvironment and killing cancer cells in primary tumors. The developed NIR-photothermal MBene is confirmed as a versatile nanoplatform capable of high-efficacy tumor-targeted drug delivery and controlled drug release.

Highly Efficient Oxygen Reduction Reaction Activity of N‐Doped Carbon–Cobalt Boride Heterointerfaces

AbstractCompositional and structural engineering of metal‐metalloid materials can boost their electrocatalytic performance. Herein, a highly efficient and stable electrocatalytic system for the oxygen reduction reaction is obtained by creating heterointerfaces between N‐doped carbon and cobalt boride nanosheets. Furthermore, a detailed investigation on the effect of annealing temperature as well as the amount of carbon and nitrogen sources is conducted to tune their performance. The best electrocatalyst among the prepared materials is found to have an onset potential of 1.05 V and half‐wave potential of 0.94 V, which are 40 and 72 mV positive in comparison to commercial Pt/C, respectively. Finally, a zinc–air battery is also assembled using the catalyst.

Direct MoB MBene domain formation in magnetron sputtered MoAlB thin films.

Two-dimensional (2D) inorganic transition metal boride nanosheets are emerging as promising post-graphene materials in energy research due to their unique properties. State-of-the-art processing strategies are based on chemical etching of bulk material synthesized via solid-state reaction at temperatures above 1000 °C. Here, we report the direct formation of MoB MBene domains in a MoAlB thin film by Al deintercalation from MoAlB in the vicinity of AlOx regions. Hence, based on these results a straightforward processing pathway for the direct formation of MoB MBene-AlOx heterostructures without employing chemical etching is proposed here.

A high-performance oxygen evolution electrocatalyst based on partially amorphous bimetallic cobalt iron boride nanosheet

The oxygen evolution reaction (OER) plays a crucial role in various electrochemical energy conversion devices, but it greatly suffers from sluggish kinetic. Therefore, developing economical and high-active electrocatalysts with superior durability and high efficiency for OER is still a huge challenge. Herein, a partially amorphous nanosheet-liked bimetallic cobalt iron boride is directly grown on the nickel foam (CoFeB-5-30 NS/NF) via a facile electroless plating method and adopted as a catalyst for OER. Benefiting from the rational designed nanosheet array which provides large surface areas and more open-pathways to obtain fast electron transportation and gas release, the resulted CoFeB-5-30 NS/NF catalyst exhibits excellent catalytic activity and superior electrochemical stability in alkaline medium. The obtained CoFeB-5-30 NS/NF exhibits an overpotential of 260 mV to reach the current density of 20 mA cm−2. Most importantly, the CoFeB-5-30 NS/NF possesses a small Tafel slope of 38 mV dec−1 and excellent stability with insignificant activity degradation after successive electrolytic measurement (for over 60 h) at 20, 50 and 100 mA cm−2 in 1.0 M KOH, respectively. This work provides a simple and rapid strategy to prepare bimetallic borides and broadens the way for the development of efficient OER catalysts.

Amorphous cobalt boride nanosheets anchored surface-functionalized carbon nanofiber: An bifunctional and efficient catalyst for electrochemical sensing and oxygen evolution reaction

Development of new metal boride with carbon composite is an emerging class of catalyst and it brings enormous curiosity in the material community because of their potential intriguing properties. Here, we describe a new type of amorphous cobalt boride (A-CoB) nanosheet anchored on the surface of functionalized carbon nanofiber (A-CoB/ƒ-CNF) by a simple method. The emerged A-CoB/ƒ-CNF composite was demonstrated to possess great bifunctional electrocatalytic activity for the electrochemical sensing of antibiotic drug nitrofurantoin (NFT) and oxygen evolution reaction (OER). The prepared A-CoB/ƒ-CNF composite was characterized by various analytical and spectroscopic techniques such as XRD, FE-SEM, HR-TEM, Raman, and XPS analysis. The result from the electrochemical impedance spectroscopy confirms that the A-CoB/ƒ-CNF composite shows high electrical conductivity and the number of electron transferability for the NFT sensor and OER which is due to the presence of abundant active sites/large surface area in A-CoB, and synergistic effect between the A-CoB and ƒ-CNF. As an electrochemical sensor, the A-CoB/ƒ-CNF modified electrode shows substantial sensitivity (3.13 μA μM−1 cm−2), wider linear response range (0.01– 527 μM), and lower detection limit (0.003 μM) as-compared to the previously reported noble and non-noble metal-based electrocatalyst for NFT sensor. As well, the A-CoB/ƒ-CNF composite demonstrates superior OER activity with low overpotential and small Tafel slope value of 0.35 V and 173 mV/dec, respectively, which shows advanced kinetics than noble metal catalysts. Based on the results, we believed that the present work gives clear evidence for the preparation of transition metal boride anchored carbon material with an outstanding catalytic activity, and hence, it can be also extended to further electrochemical applications.