氨基络合物制备氨硼烷及放氢性能研究

以NaBH₄为硼源、氨基络合物Ni(NH₃)₆Cl₂为氨源制备高储氢容量的氨硼烷(NH₃BH₃, Ammonia Borane, AB)及其放氢性能研究. 通过XRD, FTIR, ¹¹B NMR, ICP等手段分析表征了所制备产物的组成和纯度, 在此基础上探究了原料比例、反应温度、时间和溶剂等因素对产物的影响. 同时, 对不同原料比制得氨硼烷的热解放氢性能进行了研究. 实验结果表明: 当物质的量NaBH₄∶Ni(NH₃)₆Cl₂＝2∶1经过10 h的反应, 得到了纯度非常高的氨硼烷(纯度＞99%)|以NaBH₄∶Ni(NH₃)₆Cl₂＝3∶1得到的氨硼烷, 当以2 ℃/min进行升温时, 氢气释放主要集中在第一步, 并且没有硼烷和硼嗪等杂质气体的产生. 另外, 在产物中得到了金属Ni纳米颗粒, 经洗涤干燥后其粒径大小可控制在10 nm左右, 在催化氨硼烷等材料的水解放氢方面具有潜在的应用价值.     

硼-10富集硼烷Lewis碱加合物的合成

天然硼中主要含有两种稳定同位素,即硼-10和硼-11,丰度分别为19.78%和80.22%.其中,富集的硼-10同位素在核工业以及放射治疗癌症等方面有重要应用.因此,硼-10富集含硼化合物的合成具有重要的研究意义.硼烷类化合物是合成这类化合物的主要起始原料,但是目前合成硼-10富集硼烷化合物的方法还比较少.以商业可得的硼-10富集硼酸为起始原料,首先采用改进的文献方法合成了硼-10富集的Na¹⁰BH₄,Na¹⁰BH₄与碘单质反应生成乙硼烷(¹⁰B₂H₆)然后,乙硼烷与各种Lewis碱进行配位,得到了一系列硼-10富集的硼烷Lewis碱加合物,包括四氢呋喃硼烷(THF·¹⁰BH₃)、二甲基硫醚硼烷(DMS·¹⁰BH₃)、N,N-二甲基苯胺硼烷(DMA·¹⁰BH₃)、氨硼烷(NH₃·     

掺硼p型非晶硅薄膜的制备及光学性能的表征

以高氢稀释的硅烷(SiH₄ )为反应气体,硼烷(B₂H₆)为掺杂气体,利用RF-PECVD方法,在玻璃衬底上制备出掺硼的氢化非晶硅(a-Si:H)薄膜,研究了硼掺杂量对氢化非晶硅(a-Si:H)薄膜的光学性能的影响.利用NKD-7000 W光学薄膜分析系统测试薄膜的透射谱和反射谱,并利用该系统的软件拟合得出薄膜的折射率、消光系数、吸收系数等光学性能参数,利用Tauc法计算掺硼的非晶硅薄膜的光学带隙.实验结果表明,随着硼掺杂量的增加,掺杂非晶硅薄膜样品在同一波长处的折射率先增大后减小,而且每一样品均随着入射光波长的增加而减小,在波长500 nm处的折射率均达到4.3以上;薄膜的消光系数和吸收系数随着硼掺杂量的增大而增大,在500 nm处的吸收系数可高达1.5×10⁵cm^-1.在实验的硼掺杂范围内,光学带隙从1.81 eV变化到1.71 eV.     

Rh/N-GMCs纳米催化剂的制备及其催化氨硼烷水解产氢性能研究

本实验通过高温焙烧三聚氰胺和葡萄糖混合物制备出具有独特层状结构的氮掺杂石墨相炭材料(N-GMCs)。再以N-GMCs为载体采用浸渍-还原法将金属Rh负载到载体表面,最终制得Rh/N-GMCs催化剂。结果表明,Rh与NGMCs之间存在强的金属-载体相互作用,Rh的负载量为0.4%时,反应转化频率(TOF)值达到峰值,此时0.4%Rh/NGMCs催化剂的TOF为645.3 min^–1,该催化剂上氨硼烷水解的活化能(E_a)为54.0 k J/mol,氨硼烷脱氢速率随氨硼烷浓度和催化剂浓度呈现正相关,该催化剂循环10次之后,催化活性未明显下降,表明该催化剂具有较好的循环稳定性。     

新型含膦五元杂环类化合物的合成

以1-苯基磷杂环戊烷硼烷络合物为起始原料,经羧基化、酯化、格氏反应以及硅基化反应合成了两个新型的含膦五元杂环化合物——顺式-二[3,5-二-(三氟甲基苯基)](1-苯基磷杂环戊烷-2)-甲醇硼烷络合物和顺式-二[3,5-二-(三氟甲基苯基)](1-苯基磷杂环戊烷-2)-三甲基硅氧甲烷硼烷络合物,其结构经1H NMR,13C NMR,31P NMR和HR-EI-MS表征。     

铕掺杂TiO2的制备及其可见光光催化性能研究

采用溶胶-凝胶法制备了不同铕(Eu)掺杂量的TiO₂纳米颗粒(Eu-TiO₂),利用透射电镜(TEM),X射线光电子能谱(XPS),X射线衍射(XRD)及紫外可见漫反射(UV-Vis DRS)等方法对Eu-TiO₂进行了物理特性的初步表征.结果表明:与未掺杂纳米TiO₂比较,Eu-TiO₂禁带宽度变窄,具有可见光光催化活性.在可见光下(λ≥420 nm)照射下,以光催化降解染料罗丹明B(Rhodamine B,RhB)为目标反应,探讨了Eu-TiO₂不同制备条件对RhB降解光催化活性的影响,优化得到制备高活性Eu-TiO₂最佳pH为3、掺杂比例(n_Eu/n_Ti)为0.05%、煅烧温度为500 ℃.研究了可见光照射下Eu-TiO₂降解RhB和无色有机小分子水杨酸(SA)光催化反应条件及降解特性,RhB的12 h深度氧化矿化率为60.2%,SA的8 h降解率达到100%.通过跟踪测定可见光下Eu-TiO₂光催化反应过程中氧化物种的变化,研究了可见光激发Eu-TiO₂光催化反应机理,表明其光催化反应主要涉及羟基自由基(·OH)历程.     

表面敏化TiO2基复合薄膜的能带结构与光致电荷转移的研究

采用离子束溅射方法制备出TiO₂/ITO, Zr^4＋掺杂的TiO₂(TiO₂-Zr)/ITO和ZrO₂/TiO₂/ITO复合薄膜. 利用表面敏化方法制备出(1,10-邻菲咯啉)₂(3,4,5-三氟苯基)咪唑并[5,6-f]邻菲咯啉钌混配配合物[Rup₂O](p＝1,10-邻菲咯啉, O＝(3,4,5-三氟苯基)咪唑并[5,6-f]邻菲咯啉)/TiO₂/ITO, Rup₂O/TiO₂-Zr/ITO和Rup₂O/ZrO₂/TiO₂/ITO表面敏化TiO₂基复合薄膜. 表面光电压谱(SPS)表明, 表面敏化TiO₂基复合薄膜在400～600和350 nm产生的SPS响应峰的峰高比与TiO₂基复合薄膜的结构密切相关. 利用电场诱导表面光电压谱(EFISPS)确定了复合薄膜的能带结构, 其结果分析表明, 400～600 nm的SPS响应峰主要源于Rup₂O分子的中心离子Ru 4d能级到配体邻菲咯啉p₁^*和配体咪唑并邻菲咯啉p₂^*跃迁|TiO₂禁带内Zr^4＋掺杂能级的存在减小了光生载流子的复合, 增加导带光生电子的数量|ZrO₂/TiO₂异质结构的存在有利于光生电子向ITO表面的转移, 从而导致400～600 nm和350 nm SPS响应峰的峰高比的增加, 意味着光致电荷转移效率的提高.     

2D氮化碳:通过调节非金属硼掺杂C3N5阐明宽酸性及碱性pH范围的光催化析氢的反应机理(英文)

太阳能驱动水裂解产氢是一种绿色能源技术,用于制备可再生和零碳排放燃料以实现可持续能源生产.近期,氮化碳(g-C₃N₄)同素异形体C₃N₅的出现克服了g-C₃N₄的固有缺点,如光生载流子快速复合和可见光吸收差,而导致极低的光催化效率.本文将硼掺杂剂通过原子替换或间隙掺杂的方式引入到C₃N₅体系中,并利用密度泛函理论对纯C₃N₅和硼掺杂C₃N₅体系进行计算,考察了硼原子对C₃N₅电子和光学性能的影响以及其催化析氢反应(HER)机理.热力学计算结果表明,硼原子掺杂在C₃N₅体系中是可行且有利的.在N3位氮原子被硼原子取代(B_N3-C₃N₅)后,带隙(0.6 e V)变窄.与纯C     

二维Z型BCN/Sn3O4复合材料的光催化还原性能

分别以直接热聚合法和水热合成法制备得到二维硼掺杂氮化碳(BCN)和四氧化三锡(Sn₃O₄)半导体材料, 采用超声复合和煅烧复合两种方法构建了BCN/Sn₃O₄复合材料. 利用 X 射线衍射(XRD)、 紫外-可见漫反射(UV-Vis)光谱、 透射电子显微镜(TEM)等手段对所制备样品进行了表征和分析, 探讨了不同复合方法对催化剂微观结构及光电性质的影响; 以可见光下光解水制氢和活化氧制过氧化氢为模型反应考察了催化剂的光催化性能. 结果表明, BCN与Sn₃O₄能够形成二维面-面复合结构, 相比于超声复合法, 直接煅烧法更有利于有效界面的形成, 使得界面间产生Sn₃O₄到BCN的电荷迁移, 增强了BCN表面电荷密度, 并使复合材料具有更加优化的光电响应和光催化还原活性, 其中煅烧法得到的复合样品BCN/Sn₃O₄-3C(Sn₃O₄与BCN质量比为3%)表现出显著增强的光解水制氢及活化氧制过氧化氢的活性.     

三元掺杂改性锂离子电池正极材料Li3V2(PO4)3

以柠檬酸为螯合剂和还原剂, NH₄VO₃为钒源,通过溶胶-凝胶法制备了锂离子电池正极材料Li₃V₂(PO₄)₃及其三元掺杂体系Li_2.85Na_0.15V_1.9Al_0.1(PO₄)_2.9F_0.1.分别采用X射线衍射(XRD)、高分辨透射电子显微镜(HRTEM)、能量损失谱(EELS)、拉曼(Raman)光谱、扫描电子显微镜(SEM)、X射线能谱(EDS)、恒流充放电、循环伏安(CV)和交流阻抗谱(EIS)等技术对材料的微观结构、颗粒形貌和电化学性能进行分析.结果表明:在残余碳包覆的基础上, Na、Al、F三元掺杂有利于稳定Li₃V₂(PO₄)₃的晶体结构,进一步减少颗粒团聚和提升材料导电特性,促进第三个锂离子的脱出和嵌入,从而显著改善Li₃V₂(PO₄)₃的实用电化学性能.未经掺杂的Li₃V₂(PO₄)₃原粉在1/9C、1C和6C倍率下的可逆比容量分别为141、119和98 mAh·g^-1,而三元掺杂改性材料在1/9C、1C、8C和14C倍率下的比容量分别为172、139、119和115 mAh·g^-1.在1C倍率下循环300圈后,掺杂体系的比容量依然高达118 mAh·g^-1,比原粉高出32.6%.值得注意的是,这种三元掺杂还使Li₃V₂(PO₄)₃的多平台放电曲线近似转变为一条斜线,显示出可能不同的储锂机制.     

Extremely Electron-Withdrawing Lewis-Paired CN Groups for Organic p-Dopants

P-type chemical doping (p-doping) is a key technique to modulate the optical, electrical, and electronic properties of organic semiconductors. However, typical functional groups in organic p-dopants have insufficient electron-withdrawing strength, and the inevitable diffusion of dopants in host matrices degrades doping stabilities. Herein, we utilize extremely electron-withdrawing Lewis-paired CN groups as a new class of building blocks for designing unprecedentedly strong organic p-dopants with excellent doping stability. Various Lewis acids are paired with CN-functionalized conjugated molecules in the solution state, which strengthens the electron-withdrawing properties of CN groups almost twofold. The large dopants afford outstanding doping stability against continuous heating and long-term atmospheric exposure, which is promising for practical applications in devices. Given the broad applicability of this simple combinatorial approach, it may impact many fields of (opto)electronics.     

A novel luminophor and host polymer from fluorene-carbazole derivatives for preparing solution-processed non-doped blue and closed-white light devices

A novel blue light emitting polymer was designed and synthesized via alternative conjugated 9,9-dioctylfluorene and 9-(6-(9H-carbazol-9-yl)hexyl)-9H-carbazole, named PF2Cz. It exhibited high thermal stability, good film morphology and strong deep-blue emission peaks at 408 and 429?nm in film. The triplet energy level of PF2Cz (E_T?=?2.30?eV) was also improved. Non-doped and doped devices were both prepared by solution process to characterize the electroluminescent (EL) properties of PF2Cz. In non-doped devices, PF2Cz acted as blue emitter which exhibited a Commission Internation de L'Eclairage (CIE) coordinate of (0.164, 0.102) and a external quantum efficiency (EQE) values of 1.28%. Moreover, the doped phosphorescent devices utilized PF2Cz as host material obtained a closed-white light emission with a content of 1?wt% dopant. All these results indicated that the fluorene-carbazole derivatives could be a promising molecular design strategy for the synthesis of blue light and host organic semiconductors.     

Wide Band‐Gap Bismuth‐based p‐Dopants for Opto‐Electronic Applications

Ten new efficient p‐dopants for conductivity doping of organic semiconductors for OLEDs are identified. The key advantage of the electrophilic tris(carboxylato) bismuth(III) compounds is the unique low absorption of the resulting doped layers which promotes the efficiency of OLED devices. The combination of these features with their low fabrication cost, volatility, and stability, make these materials very attractive as dopants in organic electronics.     

Sterically-Hindered Molecular p-Dopants Promote Integer Charge Transfer in Organic Semiconductors

Molecular p-dopants designed to undergo electron transfer with organic semiconductors are typically planar molecules with high electron affinity. However, their planarity can promote the formation of ground-state charge transfer complexes with the semiconductor host and results in fractional instead of integer charge transfer, which is highly detrimental to doping efficiency. Here, we show this process can be readily overcome by targeted dopant design exploiting steric hindrance. To this end, we synthesize and characterize the remarkably stable p-dopant 2,2′,2′′-(cyclopropane-1,2,3-triylidene)tris(2-(perfluorophenyl)acetonitrile) comprising pendant functional groups that sterically shield its central core while retaining high electron affinity. Finally, we demonstrate it outperforms a planar dopant of identical electron affinity and increases the thin film conductivity by up to an order of magnitude. We believe exploiting steric hindrance represents a promising design strategy towards molecular dopants of enhanced doping efficiency.     

New electrolytes using Li2O or Li2O2 oxides and tris(pentafluorophenyl) borane as boron based anion receptor for lithium batteries

A new system of electrolytes has been developed and studied for lithium-ion batteries. This new system is based on the interactions between Li₂O or Li₂O₂ and tris(pentafluorophenyl) borane (TPFPB) in carbonate based organic solvents. This opens up a completely new approach in developing non-aqueous electrolytes. In general, the solubility of Li₂O or Li₂O₂ is very low in organic solvents and the ionic conductivities of these solutions are almost undetectable. By adding certain amount of tris(pentafluorophenyl) borane (TPFPB), one type of boron based anion receptors (BBARs), the solubility of Li₂O or Li₂O₂ in carbonate based solvents was significantly enhanced. In addition, the Li⁺ transference numbers of these new electrolytes measured were as high as 0.7, which are more than 100% higher than the values for the conventional electrolytes for lithium-ion batteries. The room-temperature conductivities are around 1 × 10⁻³ S/cm. These new electrolytes are compatible with LiMn₂O₄ cathode for lithium-ion batteries.     

水/醇溶共轭聚合物界面材料及其在光电器件中的应用

相对于传统的无机半导体器件,以有机半导体(特别是聚合物半导体)材料为基础的有机光电器件,可采用与传统印刷技术(例如喷墨打印、卷对卷印刷等)相结合的溶液加工方式制备低成本、大面积、柔性光电器件,因而成为广泛关注的焦点,并得到了快速发展.实现溶液加工的高效有机光电器件的一个关键问题是界面问题——如何避免溶液加工时有机层间的互溶以及如何实现可印刷稳定金属电极的高效电子注入等.水/醇溶性共轭聚合物的迅速发展为解决溶液加工多层有机光电器件所面临的界面问题提供了有效手段.研究发现,水/醇溶共轭聚合物不但可以有效避免溶液加工多层器件中的界面互溶,而且还可与高功函数的稳定金属发生界面偶极相互作用而增强其电子注入,从而解决了高功函数稳定金属电子注入的难题,为实现全溶液加工的高效印刷有机光电器件提供了可行的方案.本文介绍了近年来本课题组在水/醇溶共轭聚合物阴极界面材料及器件应用方面的研究进展,并对水/醇溶共轭聚合物阴极界面材料在聚合物发光二极管和聚合物太阳电池中的工作机理进行了探讨.     

Field Effect Devices Based on SrTiO3 Gate Dielectrics for the Investigation of Charge Carrier Mobility in Macromolecular Films

Field effect devices (FET) allow an exhaustive investigation of the electronic transport properties of innovative semiconductors of interest for new applications in modern electronics. In this contribution, we report on the fabrication and characterization of FET devices where SrTiO₃ (STO) single crystals and organic macromolecular compounds, such as doped and undoped polythiophenes, or poly(N-vinylcarbazole) (PVK), are used as insulating and semiconducting layers, respectively. STO, with ε_r of about 300, offers the possibility to strongly modulate the charge carrier density in the organic films, thus overcoming the limitations related to the use of more conventional oxides.     

Preparation and characterization of anthracenecarboxylic acid doped polyaniline thin films

Doped polyaniline films were prepared with electrochemistry method. A small conjugated molecule, anthracenecarboxylic acid(2-ACA), was used as the dopant, considering its electrical activeness due to the conjugated π-π* structure. Film morphology of doped and undoped polyaniline samples was investigated. The corresponding changes in optical and electrical properties after ACA doping were discussed. By measuring and calculating their energy level distribution, a promising application of polyaniline thin films as buffer layer in optic-electric devices is expectable.     

Dithieno[3,2‐b:2′,3′‐d]pyrrole Cored p‐Type Semiconductors Enabling 20 % Efficiency Dopant‐Free Perovskite Solar Cells

Organic p‐type semiconductors with tunable structures offer great opportunities for hybrid perovskite solar cells (PVSCs). We report herein two dithieno[3,2‐b:2′,3′‐d]pyrrole (DTP) cored molecular semiconductors prepared through π‐conjugation extension and an N‐alkylation strategy. The as‐prepared conjugated molecules exhibit a highest occupied molecular orbital (HOMO) level of ?4.82 eV and a hole mobility up to 2.16×10^?4 cm² V^?1 s^?1. Together with excellent film‐forming and over 99 % photoluminescence quenching efficiency on perovskite, the DTP based semiconductors work efficiently as hole‐transporting materials (HTMs) for n‐i‐p structured PVSCs. Their dopant‐free MA_0.7FA_0.3PbI_2.85Br_0.15 devices exhibit a power conversion efficiency over 20 %, representing one of the highest values for un‐doped molecular HTMs based PVSCs. This work demonstrates the great potential of using a DTP core in designing efficient semiconductors for dopant‐free PVSCs.     

High-performance air-stable organic field-effect transistors: isoindigo-based conjugated polymers

Two conjugated polymers, IIDDT and IIDT, based on an isoindigo core were developed for organic field-effect transisitors. Investigation of their field-effect performance indicated that IIDDT exhibited air-stable mobility up to 0.79 cm(2) V(-1) s(-1), which is quite high among polymer FET materials. The facile preparation and high mobility of such polymers make isoindigo-based polymers very promising for application as solution-processable organic semiconductors for optoelectronic devices.