Te掺杂方钴矿CoSb3的溶剂热合成及电学性能

以CoCl2,SbCl3和Te粉为原料,NaBH4为还原剂,用溶剂热方法合成了Te掺杂方钴矿CoSb（3-x）Tex（x=0,0.05,0.1,0.2,0.4）纳米粉末.研究发现,Te含量较高的样品（x≥0.2）有明显的CoTe2等杂相存在.CoSb（3-x）Tex合成粉末的粒径大小在40nm左右,热压后晶粒发生长大,平均晶粒尺寸约为300nm.电学性能测试表明Te掺杂方钴矿CoSb（3-x）Tex的导电类型为n型,Seebeck系数的绝对值随着Te含量的增加而变小,电导率随着Te含量的增加而增大.在测试温度范围内,CoSb（2.8）Te（0.2）具有最高的功率因子,在773K温度下达到2.3×10^-3W·m^-1·K^-2.     

MMA／St无皂阳离子乳液共聚合动力学

运用溶剂热法,以丙酮-水为分散介质,利用阳离子型引发剂偶氮二异丁基脒盐酸盐(AIBA)引发苯乙烯(St)和甲基丙烯酸甲酯(MMA)共聚,制备无皂MMA/St共聚阳离子纳米胶乳粒子。探讨了单体浓度、引发剂浓度、温度对共聚合初始速率的影响。结果表明,随着[MMA]和温度的增加,聚合速率增大;随着[AIBA]的增加,聚合速率先增大后减小;得到单体浓度([MMA])和引发剂浓度([AIBA])影响反应速率的动力学方程为:RP=kP.[MMA]0.68[AIBA]0.77,测得共聚合表观活化能Ea=40.7 kJ/mol。     

准单分散SnO2微球的微波溶剂热合成

以聚乙二醇(PEG, Mn=6000)为模板剂, 结晶四氯化锡(SnCl₄·5H₂O)和尿素为原料, 采用微波溶剂热法在180℃、添加0.12 mmol PEG的条件下制备出了单分散性良好的SnO₂微球. 通过XRD、SEM、TEM和FT-IR等分析手段对产物进行表征, 并结合光致发光(PL)谱研究了产物的发光性能. 结果表明: SnO₂微球是由大量细小晶粒堆积而成的, 微球直径约1.3 um. 经400℃煅烧2 h后, 微球表面致密光滑且直径未发生明显变化. FT-IR谱图中550 cm^-1处吸收峰应为表面结构改变引起的表面振动模式. PL谱表明煅烧前SnO₂微球在320~450 nm处具有宽而强的发射带, 煅烧后发射带强度大幅下降, 说明产物的晶格缺陷对近带边发射有重要影响.     

Characterisation of one-dimensional CdS nanorods synthesised by solvothermal method

One-dimensional (1D) cadmium sulfide nanorods were successfully synthesised using cadmium nitrate and sulfur powder as starting materials and polyvinyl alcohol (PVA, MW = 1 25,000) as a capping agent in ethylenediamine as a solvent by solvothermal method at 200°C for 24 and 72 h. X-ray diffraction patterns (XRD) indicated a single phase of hexagonal wurtzite CdS structure, of which the results are in accordance with those of selected area electron diffraction (SAED). The morphologies of CdS were observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) which showed 1D nanorods. The length and diameter of CdS nanorods were increased when PVA was added and the reaction times were prolonged. High resolution transmission electron microscopy (HRTEM) showed that growth direction of wurtzite CdS nanorods is along [001] direction or c-axis. Raman spectra presented the 1LO and 2LO at 299.36 and 600.72 cm^?1, respectively. The 2LO/1LO intensity ratios were increased when the length of CdS nanorods became longer.     

Electrically Conductive and Antimicrobial Agro-Food Waste Biochar Functionalized with Zinc Oxide Particles

Carbonaceous materials derived from biomass have been used as sustainable platforms for the growth of ZnO particles aiming the production of functional composite fillers. Kidney-bean pods were pyrolyzed by applying an experimental design that demonstrates that the specific surface area (S_BET) of biochar is improved with increasing pyrolysis temperature combined with a short air-oxidation time. Meanwhile, the graphitization degree and the electrical conductivity (EC) of biochars were negatively affected by increasing the air-oxidation time. The biochar sample with the higher EC and the one with the higher S_BET were selected to be functionalized with ZnO particles by a solvothermal methodology, obtaining composites with an EC and S_BET properties superior to the ZnO-rGO composite, in addition to a similar antibacterial activity. The developed ZnO-biochar composite structures, which are more ecological and biocompatible than the ZnO composites derived from graphene sheets, can be applied as electrically conductive and active fillers.     

溶剂热法制备织构化Bi0.5Na0.5TiO3陶瓷的影响因素

以Bi(NO₃)₃·5H₂O和Ti片为原料,无水乙醇为溶剂,采用溶剂热法合成了具有取向性的织构化Bi_0.5Na_0.5TiO₃(BNT)无铅压电陶瓷.采用X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)和能谱仪(EDS)对BNT无铅压电陶瓷物相、显微形貌和成分进行了表征.系统研究了NaOH浓度、[Bi³⁺]浓度、表面活性剂和溶剂等因素对BNT晶粒物相、微观形貌和成分的影响.结果表明:NaOH浓度为1 mol·L^-1,[Bi³⁺]浓度为0.1 mol·L^-1,聚乙二醇(PEG)加入量为1~6 mL,且溶剂为无水乙醇时可以制备出织构化BNT陶瓷,产物颗粒尺寸平均为10~20μm.     

回流法制备TiO_2微球及其结构和催化性能研究

采用回流法制备了介孔TiO2微球催化剂,利用XRD、FE-SEM、BET等方法对所制备的催化剂进行了表征,并与溶剂热法制备的样品进行比较,研究不同制备方法对TiO2结构、形貌及催化性能的影响。结果表明,回流法制备的样品为锐钛矿单相微球,晶粒间堆积形成介孔结构,比表面积大;而溶剂热法制备的介孔样品含金红石和锐钛矿两相。以EtOH/HCl为回流溶剂制备的样品孔径约为5 nm,孔径分布窄,比表面积可达496 m2/g,光催化去除Cr（Ⅵ）反应速率快,去除率达到99%。     

多级结构α-MoO3空心微球的构筑及其对有机染料的吸附性能

具有多级结构的半导体金属氧化物, 其特有的立体空间结构使材料具有超高活性, 在吸附领域具有应用潜力。研究采用简单的一步溶剂热法制备了空心球状的MoO₂前驱体, 400 ℃热处理后得到多级结构α-MoO₃空心微球。空心球的直径为600~800 nm, 由宽度约70 nm的纳米棒构筑而成。该球状α-MoO₃纳米材料对亚甲基蓝(MB)染料具有优良的吸附性能。当α-MoO₃吸附剂用量为0.5 g/L、MB染料浓度为20 mg/L、吸附时间为5 min时, 移除率可达到73.40%。吸附60 min时, 吸附达到平衡, 此后移除率为97.53%~99.65%。该吸附动力学过程符合拟二级动力学模型, 吸附等温线符合 Langmuir 模型拟合, 最大吸附量为 1543.2 mg/g。α-MoO₃微球由于多级且中空的纳米结构, 对MB染料具有用量少、吸附速率快和吸附完全等特点。该材料可以用于吸附废水中其他有机染料。     

溶剂热法合成Fe3O4纳米微粒及其调控机制

为探究磁性四氧化三铁(Fe₃O₄)纳米微粒的合成过程,采用溶剂热法制备Fe₃O₄纳米微粒并对其反应条件进行调控,通过扫描电子显微镜、红外光谱仪和X射线衍射仪分别对其表面形态、成分结构和晶体结构进行表征,利用振动样品磁强计测试其磁性能;研究反应时间、反应温度和聚乙二醇(PEG)用量的调控机制。结果表明,反应时间12 h、反应温度200℃、PEG含量1 mmol为最优合成条件;在该条件下制得的产物尺寸均一、形态稳定且具有良好的分散性,主体粒径在400 nm左右,且具有良好的磁性能。     

溶剂热法制备铜与氧化亚铜纳米晶

利用溶剂热法，以五水硫酸铜、氢氧化钠、无水乙醇为原料，在无水条件下通过乙醇还原氧化铜制得了形状均一、分散性较好的纳米铜颗粒；在有水条件下通过乙醇还原氧化铜合成出了一维氧化亚铜纳米棒。利用X射线粉末衍射仪（XRD）及高分辨透射电镜（HRTEM）对合成产物进行了物相与形貌分析。在实验中还发现反应温度与溶剂中水的加入量是影响乙醇还原性的主要因素，并由此决定了最终产物的相组成。