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.

Coupling Au with BO_(x) matrix induced by Closo-boron cluster for electrochemical synthesis of ammonia

Au is considered as one of the most promising catalysts for nitrogen reduction reaction(NRR),however maximizing the activity utilization rate of Au and understanding the synergistic effects between Au and carriers pose ongoing challenges.Herein,we systematically explore the synergistic catalytic effect of incorporating Au with boron clusters for accelerating NRR kinetics.An in-situ abinitio strategy is employed to construct B-doped Au nanoparticles(2-6 nm in diameter)loaded on BO_(x) substrates(AuBO_(x)),in which B not only modulates the surface electronic structure of Au but also forms strong coupling interactions to stabilize the nanoparticles.The electrochemical results show that Au-BO_(x) possesses excellent NRR activity(NH_(3) yield of 48.52μg h^(-1)mg_(cat)^(-1),Faraday efficiency of 56.18%),and exhibits high stability and reproducibility throughout the electrocatalytic NRR process.Theoretical calculations reveal that the introduction of B induces the formation of both Au dangling bond and Au-B coupling bond.which considerably facilitates the hydrogenation of~*N_(2)^(-)~*NH_(3).The present work provides a new avenue for the preparation of metal-boron materials achieved by one-step reduction and doping process,utilizing boron clusters as reducing and stabilizing agents.

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.

Effect of Water Stress and Foliar Boron Application on Seed Protein, Oil, Fatty Acids, and Nitrogen Metabolism in Soybean

Effects of water stress and foliar boron (FB) application on soybean (Glycine max (L) Merr.) seed composition and nitrogen metabolism have not been well investigated. Therefore, the objective of this study was to investigate the effects of water stress and FB on seed protein, oil, fatty acids, nitrate reductase activity (NRA), and nitrogenase activity (NA). A repeated greenhouse experiment was conducted where one set of soybean plants were subjected to water stress (WS), and the other set was watered (W). Foliar boron (B) was applied at rate of 0.45 kg·ha-1. Treatments were watered-plants with no FB (W), watered-plants with FB (WB), water-stress plants with no FB (WS), and water-stress plants with FB (WSB). The results showed that seed protein and oil percentage were significantly (P 15N/ 14N and 13C/12C natural abundance were altered between watered-and watered-stressed plants. These results suggest that water stress and FB can influence seed composition, and nitrogen metabolism, and 15N/14N and 13C/12C ratios, reflecting environmental and metabolic changes in carbon and nitrogen fixation pathways. Lack of B translocation from leaves to seed under water stress may suggest a possible mechanism of limited B translocation under water stress. These findings may be beneficial to breeders to select for B translocation efficiency under drought conditions. Altered 15N/14N and 13C/12C under water stress can be used as a tool to select for drought tolerance using N and C isotopes in the breeding programs.

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.

Computational Design of Single Mo Atom Anchored Defective Boron Phosphide Monolayer as a High-performance Electrocatalyst for the Nitrogen Reduction Reaction

Catalytic reduction of molecular dinitrogen(N_(2))to ammonia(NH_(3))is one of the most important and challenging industrial reactions.Electrochemical reduction is considered as an energy-saving technology for artificial ambient nitrogen fixation,which is emerging as an optimal potential sustainable strategy to substitute for the Haber–Bosch process.However,this process demands efficient catalysts for the N_(2)reduction reaction(NRR).Here,by means of first-principles calculations,we systematically explored the potential electrocatalytic performance of single transition metal atoms(Pd,Ag,Rh,Cu,Ti,Mo,Mn,Zn,Fe,Co,Ru,and Pt)embedded in monolayer defective boron phosphide(TMs/BP)monolayer with a phosphorus monovacancy for ambient NH_(3)production.Among them,the Mo/BP exhibits the best catalytic performance for ambient reduction of N_(2)through the typical enzymatic and consecutive reaction pathways with an activation barrier of 0.68 e V,indicating that Mo/BP is an efficient catalyst for N_(2)fixation.We believe that this work could provide a new avenue of ambient NH_(3)synthesis by using the designed single-atom electrocatalysts.

Synthesis and characterizations of boron and nitrogen co-doped high pressure and high temperature large single-crystal diamonds with increased mobility

We synthesized and investigated the boron-doped and boron/nitrogen co-doped large single-crystal diamonds grown under high pressure and high temperature(HPHT) conditions(5.9 GPa and 1290℃). The optical and electrical properties and surface characterization of the synthetic diamonds were observed and studied. Incorporation of nitrogen significantly changed the growth trace on surface of boron-containing diamonds. X-ray photoelectron spectroscopy(XPS) measurements showed good evident that nitrogen atoms successfully incorporate into the boron-rich diamond lattice and bond with carbon atoms. Raman spectra showed differences on the as-grown surfaces and interior between boron-doped and boron/nitrogen co-doped diamonds. Fourier transform infrared spectroscopy(FTIR) measurements indicated that the nitrogen incorporation significantly decreases the boron acceptor concentration in diamonds. Hall measurements at room temperature showed that the carriers concentration of the co-doped diamonds decreases, and the mobility increases obviously. The highest hole mobility of sample BNDD-1 reached 980 cm^(2)·V^(-1)·s^(-1), possible reasons were discussed in the paper.

Synthesis of boron, nitrogen co-doped porous carbon from asphaltene for high-performance supercapacitors

Oxidized asphaltene （OA）, a thermosetting material with plenty of functional groups, is synthesized from asphaltene （A） using HNO3]HzSO4 as the oxidizing agent. Boron, nitrogen co-doped porous carbon （BNC-OA） is prepared by carbonization of the mixture of boric acid and OA at 1173 K in an argon atmosphere. X-ray photoelectron spectroscopy （XPS） characterization reveals that the BNC-OA has a nitrogen content of 3.26 at.% and a boron content of 1.31 at.%, while its oxidation-free counterpart （BNC-SA） has a nitrogen content of 1.61 at.% and a boron content of 3.02 at.%. The specific surface area and total pore volume of BNC-OA are 1103 m2·g^-1 and 0.921 cm3·g^-1, respectively. At a current density of 0.1 A·g^-1, the specific capacitance of BNC-OA is 335 F·g^-1 and the capacitance retention can still reach 83% at 1 A·g^-1. The analysis shows that the superior electrochemical performance of the BNC-OA is attributed to the pseudocapacitance behavior of surface heteroatom functional groups and an abundant pore-structure. Boron, nitrogen co-doped porous carbon is a promising electrode material for supercapacitors.

Boron Nitride Quantum Dots/Ti_(3)C_(2)T_(x)-MXene Heterostructure For Efficient Electrocatalytic Nitrogen Fixation

Electrocatalytic N_(2) fixation through N_(2) reduction reaction(NRR)has been regarded as a promising route for sustainable NH_(3) synthesis,while exploring high-performing NRR catalysts is pivotal yet challenging.Herein,BN quantum dots/Ti_(3)C_(2)T_(x)-MXene(BNQDs/Ti_(3)C_(2)T_(x))heterostructure is demonstrated as an efficient and durable NRR catalyst,exhibiting a high NH_(3) yield of 52.8±3.3μg h^(-1) mg^(-1) with an FE of 19.1±1.6%at0.4 V(vs.RHE),which stand at the high level among all reported BN-and MXene-based NRR catalysts.Theoretical computations reveal that the electronic interactions between BNQDs and Ti_(3)C_(2)T_(x) enrich the electron density of B atoms at the heterointerface and endow them with enhanced electron-donating capability for N_(2) activation and protonation.Meanwhile,the decorated BNQDs can block the active sites of Ti_(3)C_(2)T_(x) for hydrogen evolution,rendering a high N_(2)-to-NH_(3) selectivity.

1+1>2: Learning from the interfacial modulation on single-atom electrocatalysts to design dual-atom electrocatalysts for dinitrogen reduction

Developing efficient electrocatalysts for converting dinitrogen to ammonia through electrocatalysis is of significance to the decentralized ammonia production. Here, through high-throughput density functional theory calculations, we demonstrated that the interfacial modulation of hexagonal boron nitride/graphene(hBN-graphene) could sufficiently improve the catalytic activity of the single transition metal atom catalysts for nitrogen reduction reaction(NRR). It was revealed that Re@hBN-graphene and Os@hBN-graphene possessed remarkable NRR catalytic activity with low limiting potentials of 0.29 V and 0.33 V, respectively. Furthermore, the mechanism of the enhanced catalytic activity was investigated based on various descriptors of the adsorption energies of intermediates, where the synergistic effect of hBN and graphene in the hybrid substrate was found to play a key role. Motivated by the synergistic effect of hybrid substrate in single-atom catalysts, a novel strategy was proposed to efficiently design dual-atom catalysts by integrating the merits of both metal components. The as-designed dual-atom catalyst Fe-Mo@hBN exhibited more excellent NRR catalytic performance with a limiting potential of 0.17 V, manifesting the solidity of the design strategy. Our findings open new avenues for the search of heterostructure substrates for single-atom catalysts and the efficient design of dualatom catalysts for NRR.

Response of Yield, Yield Components and Fiber Properties of Cotton to Different Application Rates of Nitrogen and Boron

Nitrogen （N） was applied at rates of 0, 100, 200 and 300 kg.ha^-1 and boron （B） was applied as foliar at rates 0, 500 and 1000 g.ha^-1 to study the effect of different application rates of nitrogen and boron fertilizers on yield, yield components and fiber properties of cotton. Statistical results of study showed that N application significantly （P 〈 0.05） enhanced boll number, boll weight, seed cotton weight of boll, seed cotton yield and lint yield. Results of study also indicated that the maximum seed cotton yield was recorded in case of 200 kg.ha^-1 N application rate, and this application rate resulted in 19.6% increased seed cotton yield. Statistical results also indicated that foliar application of B significantly enhanced boll number, boll weight, seed cotton yield and lint yield. Results also demonstrated that the maximum seed cotton yield was obtained in case of 1000 g.hal foliar application of B, and this foliar application rate resulted in 25% increased seed cotton yield. Statistical results showed that effect of different application rates of N was not significant for all fiber properties （fiber length, fiber strength and fiber fineness）. Conversely, results of study indicated that different application rates of B significantly affected some fiber properties.

On the ECI and CEI of Boron-Nitrogen Fullerenes

The eccentric connectivity index and connective eccentricity index are important topological indices for chemistry. In this paper, we investigate the eccentric connectivity index and connective eccentricity index of boron-nitrogen fullerenes, respectively. And we give computing formulas of eccentric connectivity index and connective eccentricity index of all boron-nitrogen fullerenes with regular structure.

Study on Tribological Behaviors of Boron-Nitrogen Modified Fatty Acid as Water-Based Lube Additives

A new type of boron-nitrogen modified fatty acid as water base lube additive was prepared and the chemical structure characterized by infrared spectrum.The tribological properties of the additive in water were evaluated by friction testers.The morphographies and tribochemical species of the worn surfaces were analyzed by means of X-ray Photoelectron Spectroscope(XPS).The results showed that the additive is excellent in increasing load-carrying capacity,anti-wear and friction-reducing abilities of water.The lubrication mechanism is inferred that a high strength adsorption film and a tribochemical reaction film are formed on the rubbing surfaces due to the carrier effect of the long chain fatty acid molecules,high reaction activities of nitrogen,electron-deficient orbit of boron and their synergisms.

氮化硼化学成分标准物质研制

研制3种氮化硼化学成分标准物质。以硼酸和三聚氰胺为原料,采用湿化学法合成固体前驱物,分别在空气和氮气气氛下高温热处理,制得质量分数为95%~99%的氮化硼候选物。随机抽取12瓶分装好的样品进行均匀性检验,组内和组间无显著性系统差异,样品均匀性良好。采用直线拟合法进行短期稳定性和长期稳定性检验,拟合直线斜率均小于临界值,样品稳定性良好。通过8家实验室采用两种不同原理的方法进行协作定值,统计评定出标准值和不确定度,定值组分包括总氮、总硼、氧化硼、铁、钙、钠,其中总氮质量分数为53.8%~55.9%,总硼质量分数为41.8%~43.7%,氧化硼质量分数为0.105%~2.37%,基本覆盖了常规氮化硼的纯度范围。该系列标准物质能够满足氮化硼相关产品的测量质量控制和测试需求。

硼对受高氨氮冲击后短程硝化系统效能恢复的影响研究

通过提高进水氨氮使稳定运行的短程硝化系统受到抑制,然后向反应器中投加硼来促进短程硝化效能的恢复。通过氮转化能力、氨氧化菌活性、胞外聚合物(EPS)中蛋白质(PN)和多糖(PS)含量、污泥形态和颗粒污泥的粒径分布来对短程硝化系统的变化进行表征。结果表明,稳定运行的短程硝化系统在短时间内受到800 mg/L氨氮冲击后短程硝化效能下降,污泥稳定性减弱,且在氨氮重新恢复到200 mg/L后短期内其效能仍无法恢复;与抑制期相比,投加硼后系统在恢复期的氨氮去除率从50%上升到95%,亚硝酸盐积累率从50%上升到85%,硝酸盐积累率从50%下降到15%,反应器的比氨氮氧化速率(SAOR)从18.65 mg/(g·h)上升到38.36 mg/(g·h),比耗氧速率(SOUR)从47.68 mg/(g·h)增加到54.24 mg/(g·h),MLSS增加了32%,达到4.5 g/L,EPS中PN质量分数比抑制期增加23%,m(PN)/m(PS)增加35.96%,信号分子AI-2质量浓度也从0.021 ng/mL增加到0.124 ng/mL。该研究结果阐明了硼对受高氨氮冲击下短程硝化系统效能的恢复有促进作用。

锌锰硼配施对雪茄烟叶光合特性、碳氮代谢及品质的影响

为探究配施不同比例锌锰硼元素对雪茄烟叶光合特性、碳氮代谢和品质的影响,以‘德雪1号’为试材,对雪茄烟生育期质体色素含量、净光合速率、碳氮代谢酶活及发酵后烟叶化学成分、锌锰硼元素含量进行分析。结果表明:(1)配施不同比例的锌锰硼元素均能提高雪茄烟烟叶质体色素含量、净光合速率以及烟叶淀粉酶、硝酸还原酶、谷氨酰胺合成酶活性和碳氮代谢产物含量,碳氮代谢更为协调;(2)处理间比较,T2处理(Zn∶Mn∶B=4∶4∶3)较CK(Zn∶Mn∶B=0∶0∶0)发酵后烟叶总糖、还原糖含量分别增加51.39%、66.67%,烟碱、总氮含量分别降低12.08%、20.22%,Zn、Mn、B含量分别提高0.17、1.98、0.65倍,钾氯比、氮碱比协调性较好,符合优质雪茄烟叶生产要求。综上可得,四川省什邡雪茄烟产区宜采用T2处理(Zn∶Mn∶B=4∶4∶3)的锌、锰、硼元素配施比例,T3处理(Zn∶Mn∶B=2∶3∶2)次之,可显著增强雪茄烟叶的光合特性、碳氮代谢强度,改善烟叶品质。

硼氮掺杂多孔碳电极材料的制备及其储能性能

【目的】制备储能性能优良的混合超级电容器,开发可再生和清洁能源存储技术。【方法】采用多孔碳作为电极材料,对多孔碳掺杂硼(B)、氮(N)等元素,增加多孔碳缺陷数量,改善多孔碳的电化学储能性能;使用乙二胺四乙酸四钠作为碳源,以硼酸铵、硼酸钠与氯化铵作为B、N掺杂源,分别制备B、N共掺杂多孔碳(B-N-多孔碳)、无掺杂多孔碳以及B、N单独掺杂多孔碳(B-多孔碳、N-多孔碳);对制得的多孔碳电极材料进行测试与表征,并进行电化学性能分析,研究多孔碳电极材料的比容量、功率密度和循环稳定性等储能性能;通过温度优化实验确定制备B-N-多孔碳的最优煅烧温度。【结果】B-N-多孔碳的孔类型主要有微孔、中孔、大孔,比表面积为668 m^(2)/g,总孔容为0.9 cm^(3)/g;N、B、C、O元素分布均匀,N、B的质量分数分别为13.12%、3.24%;石墨化程度低,结构无序程度高,缺陷数量大,离子的吸附性能强,充放电性能最佳;拥有最大的比容量和容量保持率;电荷转移内阻最小,循环性能最佳,会产生赝电容行为。【结论】当硼酸铵添加量为20 mmol,煅烧温度为700℃时,制得的B-N-多孔碳具有最好的微观形貌结构与电化学性能。

汽车座椅用抗菌涤纶针织物制备及其性能

为解决汽车座椅用涤纶针织物耐久性抗菌问题,以钛酸四丁酯为钛源、硼酸和尿素为掺杂体,采用快速溶胶-凝胶浸渍负载法,通过优化工艺制备出负载硼氮共掺杂纳米二氧化钛(B-N-TiO_(2))抗菌剂的涤纶针织物。在模拟日光照射条件下采用振荡法测试抗菌涤纶针织物对大肠杆菌和金黄色葡萄球菌的抗菌性能。分析抗菌剂的光谱性质和微观形貌,并测试织物的断裂强力、耐磨性能、拒水性能等。结果表明:当浸渍时间为5 min、焙烘温度为120℃、焙烘时间为15 min时,所制抗菌涤纶针织物对大肠杆菌和金黄色葡萄球菌的抑菌率分别为98.4%和94.4%,其主要性能均符合相关标准要求;经20次洗涤后,其纤维表面仍包覆有大量抗菌剂,且抑菌率分别为91.8%和91.3%,抗菌耐久性优于AA级。

盐浴保护渗硼对渗氮30CrMnSi钢组织与硬度的影响

30CrMnSi钢表面渗入少量的硼,可以得到优良的表面力学性能,传统盐浴渗硼工艺温度高,晶粒容易长大。实验在渗硼之前,先往30CrMnSi钢表面渗入有细化晶粒作用的氮元素,从而抑制渗硼过程中的晶粒长大。而且硼可以与30CrMnSi钢中的锰组合成Mn-B系空冷贝氏体钢,正火后观察渗层组织和测试硬度,探讨优化渗层的方法。

氮化硼高温陶瓷材料对真空感应气雾化金属粉末的影响

研究了真空感应熔炼气雾(VIGA)技术中使用高温陶瓷材料对GH4169雾化结果的影响。利用电子秤、氧氮分析仪和X射线分析雾化后不同氮化硼高温陶瓷材料用量对包铁质量、金属粉末的氧氮、高密夹杂的影响。结果表明:在浇口杯处涂抹氮化硼高温陶瓷材料可以有效地缩短清理包铁时长。随着氮化硼高温陶瓷材料用量的增加,包铁质量明显减少,采用VIGA设备生产的GH4169金属粉末氧氮值及非金属夹杂物均合格。另外,在大坩埚内部涂抹不同量的高温陶瓷材料也对金属粉末没有任何影响。本研究对了解在VIGA设备中通过使用氮化硼高温陶瓷材料来提高浇口杯寿命和减少包铁质量,具有指导意义和参考价值。