自组装花状α-Ni（OH）2和NiO的制备和表征

以硝酸镍为原料,尿素为沉淀剂,在不添加任何模板和表面活性剂条件下,采用均匀沉淀法制备出具有自组装结构的花状α型Ni(OH)2,并以其为前驱体,制得了同样具有花状结构的NiO。采用XRD、SEM、HRTEM、TG和低温液氮吸附技术对样品的晶相结构、表面形貌和孔径结构等进行表征。测试结果显示,所制备的样品是α型Ni(OH)2,比表面积是245.0m2/g,而且这些直径为4～6μm的花状Ni(OH)2是由许多纳米薄片相互组装而成。将花状Ni(OH)2在400℃焙烧2h即可获得具有花状结构的NiO,其比表面积为125.2m2/g。     

水热合成三维花状薄水铝石微观结构

在水溶液体系中,利用十六烷基三甲基溴化铵（CTAB）作为模板剂,水热合成了由纳米薄片自组装成的三维花状薄水铝石微观结构,采用XRD、SEM和TEM对其物相结构和形貌进行了分析,研究表明,该花状微观结构是由厚度50mm左右的纳米薄片自组装而成,形貌规则统一,分散均匀,平均直径为1．5μm,在其形成过程中,模板剂CTAB起到关键性的作用,并推断了纳米薄片自组装花状微观结构的形成机理。经过500℃焙烧得到的γ-Al2O3保持了该花状微观结构。     

一步沉淀法制备三维分等级花状α-Bi2 O3微球及其光性能

以乙醇-水为溶剂体系、丙三醇为封端剂,在低温(95℃)及常压下,采用水相一步沉淀法,以Bi(NO_3)_3·5H_2O为铋源、NaOH为沉淀剂,反应1 h制备出两种三维分等级花状α-Bi_2O_3微球。采用X射线衍射仪(XRD)和场发射扫描电子显微镜镜(FE-SEM)表征Bi_2O_3样品的晶型和微观形貌。结果表明,样品均为α相,尺度在微米级,随丙三醇浓度不同,微观形貌分别为纳米立方体3D自组装分等级花状微球和一维纳米棒自组装分等级花状微球。初步分析了特殊微观形貌形成的机理。紫外-可见光谱(UV-Vis)分析表明,样品均在紫外-可见光区有显著的光吸收,两种样品的禁带宽度分别为2.76 eV和2.70 eV,属于电子从价带跃迁到导带引起的吸收,为Bi_2O_3的直接带隙吸收。荧光光谱(PL)分析表明,样品在400～600 nm均具有五个发射谱带(谱带中心位于450 nm、466 nm、480 nm、490 nm和562 nm处)。微观形貌影响荧光发射谱带的波形与强度,纳米棒自组装而成的花状分等级微球的荧光强度稍弱。     

花状CdO微球的制备及其对高氯酸铵热分解的催化性能

采用溶剂热合成-热分解两步法制得花状CdO微球。以醋酸镉为原料、甲醇为溶剂,采用溶剂热法合成由纳米片自组装而成的花状前驱体微球。将前驱体焙烧后,得到形貌保持良好的花状多孔CdO微球。利用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、热重(TG)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和N_2吸附-脱附等手段对样品的物相、化学组成、形貌及孔结构进行表征。借助差示扫描量热(DSC)技术对CdO花状微球催化高氯酸铵(AP)热分解的性能进行评价。结果表明:花状CdO微球对AP热分解过程具有一定的催化作用。添加质量分数为2%的CdO可使AP的高温分解峰值温度从444.4℃降低至402.8℃,分解热从586.9 J/g提高到1091.7 J/g,分解活化能从280.5 kJ/mol减小至83.78 kJ/mol。基于实验结果,提出了CdO花状微球催化AP热分解的可能机理。     

花状纳米铜的制备及抗菌性能

采用液相化学还原法分别制备了聚乙烯吡咯烷酮(PVP)和羧甲基壳聚糖(NOCC)修饰的花状铜纳米材料。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线粉末衍射仪(XRD)等对所得样品的形貌和结构进行了表征。结果表明,所制备样品具有面心立方铜的晶体结构,SEM观察下,铜纳米微粒以PVP和NOCC为软模板自组装生长花状纳米结构。分别通过抑菌圈法和肉汤稀释法测试了样品对3种常见菌种的抑菌圈直径、最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。结果表明,所制备样品对大肠杆菌(E.coli)、金黄色葡萄球菌(S.aureus)及绿脓杆菌(P.aeruginosa)均具有优异的抑菌杀菌作用。     

水热法制备花状γ-AlOOH

以十八水合硫酸铝和尿素为原料,十六烷基三甲基溴化铵(CTAB)和酒石酸钠为表面活性剂,在165℃水热条件下反应3h,制备花状γ-AlOOH结构。采用扫描电镜(SEM)、热重分析和X射线衍射(XRD)对样品进行表征。实验结果表明,采用水热法可以得到长度、厚度均匀的γ-AlOOH纳米片组装成的花状γ-AlOOH。     

花状ZnO超细结构的水热自组装

通过简单的水热合成路线,合成出由ZnO纳米棒束组装的花状结构.其组成结构单元ZnO纳米棒沿［001］晶向生长,呈很好的单晶结构.大部分纳米棒直径约为500nm,长约6.0μm.研究结果表明,在无水乙二胺存在的条件下,氨水（28%, v/v）在ZnO花状结构的形成过程中起到了至关重要的作用.调节氨水的含量,组成结构单元ZnO纳米棒可以组装成不同的花状结构.当加入氨水的量使得溶液的pH值达到10时,即可得到由ZnO纳米棒束组装成的花状结构,并简单讨论了这种花状结构的形状结构的形成机理.      

N-甲基-2-[4-二甲基氨基]苯基-3,4-富勒烯基吡咯烷微米花的控制合成及性能研究

以富勒烯C60、4-(N,N-二甲基氨基)苯甲醛为原料,通过1,3-偶极环加成反应合成了N-甲基-2-[4-二甲基氨基]苯基-3,4-富勒烯基吡咯烷(NMDAPF)。首次采用表面活性剂协助自组装的方法制备出该C60衍生物的微米花状结构,通过扫描电子显微镜(SEM)、高分辨透射电子显微镜(HRTEM)、选区电子衍射(SAED)、拉曼光谱(Raman)、热重分析(TGA)和荧光光谱(PL)进行表征,考察了溶液浓度、醇与溶剂体积比、表面活性剂种类、表面活性剂浓度以及温度对其形貌和晶体结构的影响。结果表明:在CCl4溶剂中,该C60衍生物溶液浓度为1.0mg/mL,异丙醇与CCl4体积比为4∶1,以十六烷基三甲基溴化铵(CTAB)为表面活性剂,其浓度为5.0mmol/L,温度为20℃时,NMDAPF晶态形貌为规整的微米花状结构。     

氢氧化钴/氢氧化镍复合材料的制备及电化学性能研究

过渡金属氧化物(氢氧化物)由于其优良的电容特性而受到极大的关注,其中Co(OH)_2和Ni(OH)_2是研究的热点。采用电化学沉积法制备不同摩尔比的Co(OH)_2/Ni(OH)_2复合材料,利用XRD和SEM对沉积产物进行结构和形貌表征,同时采用循环伏安法、恒电流充放电以及电化学阻抗谱对电极材料进行电化学性能测试。结果表明,电化学沉积法可以制备出不同摩尔比的Co(OH)_2/Ni(OH)_2复合材料,电极材料为纳米花状结构,而这种结构大幅增加了活性材料的比表面积。随着沉积溶液中Co(NO_3)_2或Ni(NO_3)_2含量的增加,Co(OH)_2/Ni(OH)_2电极材料的放电时间与比电容值呈现先增大后减小的趋势。其中,当沉积溶液中Ni(NO_3)_2∶Co(NO_3)_2=1∶1时,所沉积的Co(OH)_2/Ni(OH)_2复合材料的放电时间最长、比电容值最大,可达到841.15 F/g。     

以硫酸钛和氟硅酸水热法制备花状多级TiO_2微球（英文）

以廉价的硫酸钛为原料和氟硅酸为结构控制剂,用成本低效益好的水热法制备暴露{001}面纳米片组装的花状多级TiO2微球。这些多级微球是由许多交联的纳米片组装。通过调变氟硅酸根离子的浓度可以容易地控制多级微球的精细结构。通过XRD和SEM表征来检测微球的生长过程,并提出了可能的形成机理。与其他溶解热合成法相比,这种成本低效益好的水热合成法有望应用于大批量生产花状多级TiO2微球。这种精制的花状多级TiO2微球展现了很好的光催化降解甲基橙的能力。     

Microwave-assisted hydrothermal synthesis of Ni(OH)2 architectures and their in situ thermal convention to NiO

The Ni(OH)₂ architectures with flower-like morphology assembled from nanosheets have been successfully synthesized through a microwave-assisted hydrothermal method using urea as a hydrolysis-controlling agent and polyethylene glycol (PEG) as a surfactant. The NiO architectures with similar morphology were obtained by a simple thermal decomposition process of the precursor Ni(OH)₂. The as-obtained products were well characterized by XRD, TG-DTA, SEM, TEM, FTIR and UV–Vis. The experimental results shown that flower-like Ni(OH)₂ architectures with a diameter of 2.5–4.0 μm are assembled from nanosheets with a thickness of 10–20 nm and width of 0.5–1.5 μm. The UV–Vis experimental results shown that the absorption edge of the NiO architectures have a blue-shift with the increasing of the calcination temperature.     

混合氨-碱沉淀剂制备Ni(OH)_2/还原氧化石墨烯复合材料及其电化学性能

利用简单易行的化学沉淀-回流法制备了Ni(OH)_2/还原氧化石墨烯(RGO)复合材料,研究了不同混合氨-碱沉淀剂对复合材料电化学性能的影响。采用XRD、拉曼光谱(Raman)和SEM表征Ni(OH)_2/RGO复合材料的微观结构和形貌。当以NH_3·H_2O-NaOH作为沉淀剂时,Ni(OH)_2/RGO复合材料中β-Ni(OH)_2纳米片均匀分散在石墨烯片层之间,形成相互插层结构。利用循环伏安(CV)、恒电流充放电(GCD)和电化学交流阻抗(EIS)测试了复合电极材料的电化学性能。研究结果表明:放电倍率为0.2C时,Ni(OH)_2/RGO复合电极材料的放电比容量达到344.8mAh/g,比β-Ni(OH)2的放电比容量高出约29%;5C时放电比容量为274.5mAh/g,经过50个循环,容量保持率为98.8%,呈现出良好的倍率性能和循环性能。     

Enhanced adsorption performance of hierarchical S-doped Ni(OH)<Subscript>2</Subscript> hollow nanocomposites for the removal of Congo red

In this work, nonmetallic S was doped into hierarchical Ni(OH)₂ hollow microspheres by ethanol solvothermal method using thiourea as sulfur source. Although the morphology of precursor Ni(OH)₂ is maintained, the surface states and pore properties had greatly changed after S doping. Using the as-prepared S-doped Ni(OH)₂ as adsorbents for the removal of Congo red (CR), the S-doped Ni(OH)₂ exhibited much better adsorption capacity compared with undoped Ni(OH)₂. The adsorption behavior of both Ni(OH)₂ and S-doped Ni(OH)₂ followed the pseudo-second-order kinetic model and intraparticle diffusion model. The equilibrium data of Ni(OH)₂ could be better fitted by Langmuir model, while Freundlich model could be better used to describe the S-doped Ni(OH)₂ with a much larger adsorption capacity toward CR. The tuned microstructure and changed surface states of adsorbent after S doping may be responsible for the enhanced adsorption performance. Therefore, the doping of S species into hierarchical Ni(OH)₂ paves a new way to tune the microstructure and surface states of Ni-based materials.     

A new perspective on carbon nano-onion/nickel hydroxide/oxide composites: Physicochemical properties and application in hybrid electrochemical systems

Carbon nano-onion (CNO) and Ni(OH)₂ or NiO composites were prepared by chemical loading of Ni(OH)₂ on the carbon surface. The samples were characterized by transmission electron microscopic (TEM) and scanning electron microscopic (SEM) methods, powder X-ray diffraction (XRD) technique and by differential-thermogravimetric analyses (TGA-DTG). The porosity properties were characterized by using nitrogen gas adsorption analyses. Pristine inorganic samples of NiO and Ni(OH)₂ revealed different morphologies and porous characteristics when compared to those of the CNO composites, which showed unique electrochemical properties. The electrochemical performance of the CNO/Ni(OH)₂ or CNO/NiO composites is largely affected by the mass, the morphology, the crystal phases of the inorganic component and the distribution of the Ni(OH)₂/NiO phase. The CNO composites were used as materials for hybrid charge-storage devices.     

Ni (OH)2-碳纳米管-还原氧化石墨烯复合材料的制备及电化学性能

利用简单易行的一步水热法制备了Ni（OH）₂-碳纳米管-还原氧化石墨烯（Ni（OH）₂-CNTs-RGO）三元复合材料,研究了不同水热反应温度对三元复合材料性能的影响。采用XRD、FTIR、Raman、X射线光电子能谱（XPS）、SEM及TEM对Ni（OH）₂-CNTs-RGO复合材料的结构和表面微观形貌进行表征。利用循环伏安（CV）、电化学交流阻抗（EIS）和恒电流充放电测试了复合电极材料的电化学性能。研究结果表明,当反应温度为120℃时,所制备的Ni（OH）₂-CNTs-RGO复合材料具有大的比表面积和三维网状结构,复合材料中六角形的β-Ni（OH）₂纳米片和CNTs均匀分散在RGO片层表面,有效阻止了RGO的团聚。Ni（OH）₂-CNTs-RGO复合电极材料在充电倍率为0.2 C时,放电比容量达到362.8 mAh/g,5 C时放电比容量为286.2 mAh/g,仍大于Ni（OH）₂在0.2 C时的放电比容量,表明CNTs与RGO的协同作用有效提高了电极材料的导电性和活性物质的利用率,最终提升了Ni（OH）₂-CNTs-RGO复合材料的倍率性能。     

Preparation and electrochemical performance of nano-scale nickel hydroxide with different shapes

Platelet-like, flake-like, and needle-like nano-scale β-Ni(OH)₂ particles were prepared by coordination homogeneous precipitation method in this paper. X-ray diffraction (XRD), transmission electron microscopy (TEM) and infrared absorption spectra (IR) were used to characterize the microstructure and morphology of the products. The nano-scale Ni(OH)₂ composite electrodes were prepared by mixing 10 wt.% samples with spherical Ni(OH)₂ to carry out charge-discharge test. The results show that the nano-scale Ni(OH)₂ composite electrodes have higher discharge specific capacity, and the nickel hydroxide nanoneedles show a better adulteration performance than the others.     

Controllable Synthesis of 3D Ni(OH)2 and NiO Nanowalls on Various Substrates for High‐Performance Nanosensors

Large‐area and uniform three‐dimensional (3D) β‐Ni(OH)₂ and NiO nanowalls were synthesized on a variety of rigid and flexible substrates via a simple aqueous chemical deposition process. The β‐Ni(OH)₂ nanowalls consist of single‐crystal Ni(OH)₂ nanosheets that were vertically grown on different substrates. The height, crystallinity, and morphology of the Ni(OH)₂ nanowalls can be readily modified by adjusting the reaction time and concentration of the NiCl₂ solution. The synthesis mechanism of the Ni(OH)₂ nanowalls was determined through heterogeneous nucleation and subsequent oriented crystal growth. 3D NiO nanowalls were obtained by thermal decomposition of the Ni(OH)₂ nanowalls at 400 °C in Ar atmosphere. Highly sensitive, selective gas sensors and electrochemical sensors based on these NiO nanowalls were developed. The chemiresistive gas sensors based on the NiO nanowalls grown on ceramic substrates exhibited an excellent performance with low detection limit for formaldehyde (8 ppb) and NO₂ (15 ppb). The electrochemical sensor based on the NiO nanowalls grown on an FTO glass substrate had a superior selectivity to non‐enzymatic glucose with a detection limit of 200 nm .     

阴离子对掺杂Co2+纳米Ni（OH）2性能的影响

为了考察阴离子种类对掺杂Co2+纳米Ni(OH)2性能的影响,采用不同镍盐制备出掺杂Co2+纳米Ni(OH)2,并采用X射线衍射(XRD)、透射电子显微镜(TEM)、循环伏安技术(CV)和恒流充放电方法对材料物化性能和电化学性能进行了研究.研究结果表明,掺杂Co2+的纳米Ni(OH)2为β-Ni(OH)2,衍射峰发生明显宽化.样品颗粒的尺寸为60~100 nm,阴离子的变化对制得的Ni(OH)2的表观形貌有影响.恒流充放电实验表明,阴离子为NO3-时,样品的质量比容量较高,0.2 C放电达到了234.6 mAh.g-1.循环伏安测试表明,阴离子为SO42-时,样品有较好的可逆性,阴离子为NO3-或SO42-时有较高的质子扩散系数.     

Synthesis and characterizations of nano-sized Ni(OH)2 and Ni(OH)2/poly(vinyl alcohol) nano composite

Nano-sized Ni(OH)₂ was synthesized by a co-precipitation method. Peaks between 500 and 750 cm⁻¹ in Fourier transform infrared spectroscopy (FTIR) confirmed the presence of metal hydroxide stretching. Thermo gravimetric analysis inferred that 69 wt% residue remained above 750 °C. High-resolution transmission electron microscopy analysis of Ni(OH)₂ revealed its size ranged from 80 to 110 nm with smooth morphology. Scanning electron microscopy inferred that pure Ni(OH)₂ has nano rod-like morphology and higher weight percentage of aniline-intercalated Ni(OH)₂ has agglomerated structure. UV–Vis spectrum detected the presence of Ni²⁺ ions at 210 nm and the existence of amino group in the basal spacing of Ni(OH)₂ was not clearly appeared in the spectrum. Photoluminescence (PL) inferred that aniline-intercalated Ni(OH)₂ showed higher PL intensity than the pristine poly(vinyl alcohol) its and nano composite.