以石墨烯为核树状大分子包覆Co纳米复合材料制备及其吸附性能研究

通过化学还原法制备了以石墨烯为核树状大分子包覆Co纳米复合材料。利用FTIR、TG、XRD和TEM对所制备产物进行了结构表征。考察了不同p H、吸附时间和温度条件下,制备的以石墨烯为核第三代数树状大分子纳米复合材料(G3.0-PAMAM/Co)对刚果红吸附效果的影响。结果表明,G3.0-PAMAM/Co对刚果红是强有力的磁性吸附剂;对刚果红的吸附动力学能符合Lagergren准二级吸附模型,主要为化学吸附;吸附热力学能符合Langmuir等温吸附模型,最大吸附量可达161.49 mg/g。     

MIL-53(Fe)金属有机骨架材料对刚果红的高效吸附

通过水热法制备规则外形的MIL-53(Fe)金属有机骨架材料(MOF),并通过傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)对材料进行表征。以刚果红作为目标物,研究所制得的MOF材料对其的吸附行为。结果表明,MIL-53(Fe)对刚果红的吸附动力学符合准二级动力学,吸附模型符合Langmuir吸附模型。MIL-53(Fe)材料对刚果红的最大吸附量为1 482 mg/g,是可望用于去除染料废水刚果红的高效吸附材料。     

镁铝铁类水滑石对苯酚的吸附特性及机理研究

通过共沉淀法制备了层状双金属氢氧化物Mg/Al/Fe-LDHs,考察了LDHs投加质量、苯酚初始质量浓度、溶液pH和反应温度(T)对苯酚吸附特性的影响。结果表明，LDHs投加质量为0.5 g、苯酚初始质量浓度为10 mg/L、pH=8.0、T=35℃最佳吸附条件下，平衡吸附量达17.41 mg/g。吸附过程符合一级动力学方程，吸附速率为0.021 7 min^-1,平衡吸附量为9.30 mg/g。吸附前后材料的XRD和FT-IR表征结果表明，LDHs吸附苯酚机理不仅涉及表面吸附，还包括LDHs板层结构重建和羟基离子置换。     

微波辅助制备柱撑膨润土对刚果红的吸附性能

用微波辅助制备锆铝柱撑膨润土,考察其对废水中刚果红染料的吸附行为,并对吸附前后柱撑膨润土进行表征,以探索吸附机理. 结果表明,在原始溶液pH和室温条件下,初始浓度为50 mg/L的刚果红溶液,吸附剂用量为4 g/L时,吸附45 min后即能达到吸附平衡,柱撑膨润土的吸附容量为12.17 mg/g,脱色率达97.64%;其吸附过程符合准二级动力学方程,粒子扩散不是唯一的速率控制步骤;锆铝柱撑膨润土对刚果红的等温吸附符合Langmuir方程;XRD与FT-IR表征结果表明,吸附过程主要以物理吸附为主.     

纳米二氧化钛包覆沙对水中有机染料的吸附

以Ti(SO_4)_2和库布齐沙漠沙为原料,制备了纳米二氧化钛包覆沙。以X射线衍射及氮气吸附-脱附分析对样品进行了表征,并测试了合成样品对刚果红的吸附性能。结果表明,制备的样品为二氧化钛与沙子的纳米复合物,其比表面积随二氧化钛含量的升高而增大,最高可达87.1 m²/g。且该纳米复合物对刚果红的吸附性能与溶液酸碱度有关,吸附符合准二级吸附动力学模型以及Langmuir吸附等温式,为单分子层吸附,最大吸附量为246.3 mg/g。     

改性海藻酸钠的制备及吸附性能研究

以海藻酸钠为原料,氯化钙为交联剂,制备了改性海藻酸钠吸附材料。采用红外光谱(FT-IR)对改性海藻酸钠进行表征,用原子吸收光谱测定其对Cd~(2+)的吸附性能。结果表明,改性海藻酸钠成功制备。吸附性能分析表明,吸附动力学过程符合准二级动力学模型,平衡吸附量为87.87 mg/g。     

纳米二氧化钛包覆沙对水中有机染料的吸附

以Ti(SO_4)_2和库布齐沙漠沙为原料,制备了纳米二氧化钛包覆沙。以X射线衍射及氮气吸附-脱附分析对样品进行了表征,并测试了合成样品对刚果红的吸附性能。结果表明,制备的样品为二氧化钛与沙子的纳米复合物,其比表面积随二氧化钛含量的升高而增大,最高可达87.1 m~2/g。且该纳米复合物对刚果红的吸附性能与溶液酸碱度有关,吸附符合准二级吸附动力学模型以及Langmuir吸附等温式,为单分子层吸附,最大吸附量为246.3 mg/g。     

介孔Fe2O3的化学沉淀法制备及其吸附性能

采用气-液化学沉淀法制备介孔Fe2O3纳米粒子。通过平衡实验,研究了Fe2O3对刚果红的吸附热力学和动力学性能。结果表明,Fe2O3对刚果红的吸附等温线符合Langmuir方程,且温度越高,吸附量越大。计算后得到的参数表明介孔Fe2O3对刚果红的吸附过程是一种自发的、吸热过程。同时,在6 h内,即可对35 mg/L刚果红溶液达到平衡,Fe2O3对刚果红的吸附动力学符合二级吸附动力学模型,主要以化学吸附为主。     

磁性NiO的制备及其选择性吸附性能

采用简单溶液法合成了分等级花状磁性氧化镍(NiO)微球,研究了制备的花状磁性NiO微球对水中染料刚果红的吸附效果,并探讨了吸附机理。结果表明,花状磁性NiO微球对刚果红的最大吸附量达155.9 mg/g,吸附机理可归因于带正电荷的吸附剂表面与阴离子染料刚果红之间的静电相互作用。磁性NiO微球能通过磁铁快速从溶液中分离,且对阴离子染料具有良好的选择吸附性能。     

磁性镍铬水滑石的制备及性能研究

采用水热法制备NiCr水滑石,然后将水滑石与磁性基质Fe3O_4进行组装,合成磁性NiCr水滑石。通过XRD、SEM、FT-IR、BET、VSM等手段对Fe3O_4/NiCr-LDHs的性能进行了表征。以刚果红为目标污染物,考察了吸附时间、溶液初始pH、吸附剂投加量、溶液初始质量浓度等对吸附效果的影响,并对吸附动力学、等温线、吸附热力学进行了探讨。结果表明,在25℃、pH 4. 5条件下,0. 050 g的Fe3O_4/NiCr-LDHs对质量浓度为50 mg/L的刚果红去除率达96. 68%。吸附动力学和热力学研究表明,磁性NiCr水滑石对刚果红的吸附符合Langmuir等温吸附方程,吸附动力学符合准二级动力学模型,吸附过程是自发进行,且在外部磁场作用下该磁性NiCr水滑石能够实现快速分离回收。     

Facile synthesis of α-MnO2 micronests composed of nanowires and their enhanced adsorption to Congo red

In this paper, α-MnO₂ micronests composed of nanowires were fabricated via a hydrothermal reaction of MnSO₄·H₂O and K₂S₂O₈ solutions. The α-MnO₂ micronests were demonstrated to have a higher adsorption capacity than γ-MnO₂ microspheres due to their large specific surface area. The amount of Congo red adsorbed per unit weight of α-MnO₂ micronests increased significantly from 114 to 282 mg·g^-1 with concentration of Congo red solution increasing from 50 to 200 mg·L^-1, but it had a little change with temperature. Kinetics, isotherms and thermodynamics for the adsorption of Congo red on α-MnO₂ micronests were examined. The adsorption process followed the pseudo-second-order kinetics with good correlation. The experimental data were analyzed by Langmuir and Freundlich models, and equilibrium data fitted the Langmuir isotherm very well with maximum monolayer adsorption capacity of 625 mg·g^–1 at 22 °C. The adsorption was spontaneous and endothermic according to thermodynamic studies. The experimental results indicate that α-MnO₂ micronests possess a high adsorption capacity and could be employed as a replacement of traditional sorbents.     

Fabrication of nickel oxide functionalized zeolite USY composite as a promising adsorbent for CO2 capture

Adsorption process is considered to be the most promising alternative for the CO₂ capture to the traditional energy-intensive amine absorption process, and the development of feasible and efficient CO₂ adsorbents is still a challenge. In this work, the NiO@USY (ultrastable Y) composites with different NiO loadings were prepared for the CO₂ adsorption using Ni(NO₃)₂ as the precursor. The composites were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, nitrogen adsorption–desorption test, scanning electron microscopy analysis, and thermogravimetric analysis, and were evaluated for the CO₂ adsorption capacity, CO₂/N₂ adsorption selectivity and CO₂ cycle adsorption capacity. The characterization results show that after the activation at 423 K, the Ni(NO₃)₂ species were well dispersed into the surface of zeolite USY, and after the further activation at 823 K, Ni(NO₃)₂ could be converted into highly dispersed NiO. The adsorption results show that the presence of the active component NiO plays an important role in improving the CO₂ adsorption performance, and the NiO@USY composite with a NiO loading of 1.5 mmol·g^-1 USY support displays a high adsorption capacity and adsorption selectivity for CO₂, and shows a good cycle stability. In addition, the Clausius–Clapeyron equation was used to evaluate the isosteric heat of adsorption of CO₂ on the NiO(1.5)@USY composite, and the heat of adsorption was 17.39–38.34 kJ·mol^-1.     

改性纳米纤维素对磷的动态吸附及再生

以铁改性纳米纤维素[Fe(OH)₃@CNFs]为吸附剂进行动态吸附除磷试验，探究了不同柱高和不同流速对Fe(OH)₃@CNFs吸附磷性能的影响。结果表明：吸附柱填充越高（6～16cm），进水流速越慢（5～10mL/min），吸附达到平衡所需时间越长，越有利于Fe(OH)₃@CNFs对磷的动态吸附。采用NaOH溶液对吸附剂解吸进行原位再生，再生后吸附柱对磷的吸附量为原吸附柱的83%，表明Fe(OH)₃@CNFs材料具有较好的再生能力。通过Yoon-Nelson模型计算吸附50%目标污染物所需的时间，拟合值与实验值的平均相对偏差在1.8%～6.9%之间，表明Yoon-Nelson模型能够很好地描述Fe(OH)₃@CNFs材料对磷的动态吸附行为。使用红外光谱和X射线光电子能谱对吸附机理进行分析发现Fe(OH)₃@CNFs材料对磷具有吸附能力，并且吸附后主要以FePO₄和Fe₂(HPO₄)₃的形式存在。利用吸附柱对生活污水处理厂二沉池出水进行动态吸附，在流速为10mL/min、填装高度为12cm的条件下，饱和时的吸附容量为34.5mg/g。     

氧化镍/碳纳米管构筑准固态不对称超级电容器及电化学性能

以Ni(NO₃)₂为原料、NaOH为沉淀剂和羟基化碳纳米管（CNT）为基质首先制备了Ni(OH)₂/CNT复合材料, 然后将其于一定温度下煅烧，使其转变为NiO/CNT复合材料。用X射线粉末衍射仪（XRD）、场发射电子显微镜（FESEM）和透射电子显微镜（TEM）表征了样品的晶相与形貌，结果表明NiO纳米粒子紧密锚附在碳纳米管表面。复合材料可能的形成机理被提出。采用循环伏安法（CV）、单电极充放电和电化学阻抗研究了反应条件对其电化学性能的影响，确定最佳制备条件。将复合材料正极、活性炭负极和PVA-KOH电解质膜组装成准固态不对称超级电容器，电化学性能测试结果表明，在充放电电流密度11.2mA/cm²下，其比电容达到868.0F/g并保持稳定循环3700圈。7500次循环后，其比电容值仍有564.2F/g，显示出高的比电容和长的循环稳定性。     

铝基锂吸附剂制备及其吸附性能研究

以氯化锂、无水氯化铝为原料,通过正交实验优化反应合成条件,采用“一步法”制备LiCl·2Al（OH）₃·nH₂O型铝基锂吸附剂。分别探究了吸附时间、吸附温度、溶液初始pH、溶液初始Li⁺浓度对吸附性能的影响,对吸附前后的无机铝吸附材料做了表征,并考察了吸附剂的离子选择吸附性及稳定性能。结果表明：最佳吸附条件为在45 ℃下pH=7的锂溶液中吸附2 h,吸附容量高达到8.66 mg/g。XRD、FT-IR表征结果表明：所制吸附材料有良好的稳定性。且该吸附剂对Li⁺分配系数（K=10.06）远高于其他金属阳离子,吸附材料经5次循环使用后,吸附容量仍能保持原来的91.5%。在西藏龙木错盐湖卤水中,对锂的吸附量达到5.24 mg/g。吸附平衡数据拟合结果表明：铝基锂吸附剂符合Langmuir等温吸附模型,吸附是发生在吸附剂表面的单层吸附;吸附过程符合伪二级动力学,是典型的化学吸附过程。     

α/γ-氧化铝对合成镁铝水滑石结构性能的影响

为了解α-氧化铝和γ-氧化铝合成镁铝水滑石（LDH）结构性能的差异,以α-氧化铝和γ-氧化铝为原料采用水热法合成了镁铝水滑石α-LDH-2.0和γ-LDH-2.0。通过扫描电镜（SEM）、红外光谱（FT-IR）、拉曼光谱（Raman）、X射线光电子能谱（XPS）、X射线衍射（XRD）、热重分析（TG-DTG）等对α-LDH-2.0和γ-LDH-2.0进行了检测,并将α-LDH-2.0和γ-LDH-2.0用于吸附刚果红的实验。结果表明：γ-氧化铝合成的γ-LDH-2.0板层更无序、结晶度较高,吸附实验中γ-LDH-2.0对刚果红的吸附效果强于α-LDH-2.0,并且适应更广的溶液pH范围,说明使用不同晶型的氧化铝可以调控镁铝水滑石的形貌结构使其高效吸附刚果红。当刚果红质量浓度为100 mg/L、镁铝水滑石添加量为20 mg时,α-LDH-2.0和γ-LDH-2.0对刚果红的吸附量较大,酸性条件更有利于α-LDH-2.0和γ-LDH-2.0对刚果红的吸附,α-LDH-2.0和γ-LDH-2.0去除刚果红的吸附动力学更符合拟二级动力学方程,等温吸附过程符合Langmuir模型。     

Novel hierarchical yolk-shell α-Ni(OH)2/Mn2O3 microspheres as high specific capacitance electrode materials for supercapacitors

For high performance supercapacitors, novel hierarchical yolk-shell a-Ni(OH)₂/Mn₂O₃ microspheres were controllably synthesized using a facile two-step method based on the solvothermal treatment. The unique a-Ni(OH)₂ based yolk-shell microstructures decorated with numerous interconnected nanosheets and the hetero-composition features can synergistically enhance reactive site exposure and electron conduction within the microspheres, facilitate charge transfer between electrolyte and electrode materials, and release structural stress during OH⁻ chemisorption/desorption. Moreover, the Mn₂O₃ sediments distributed over the a-Ni(OH)₂ microspheres can serve as an effective protective layer for electrochemical reactions. Consequently, when tested in 1 mol·L⁻¹ KOH aqueous electrolyte for supercapacitors, the yolk-shell a-Ni(OH)₂/Mn₂O₃ microspheres exhibited a considerably high specific capacitance of 2228.6 F·g⁻¹ at 1 A·g⁻¹ and an impressive capacitance retention of 77.7% after 3000 cycles at 10 A·g⁻¹. The proposed a-Ni(OH)₂/Mn₂O₃ microspheres with hetero-composition and unique hierarchical yolk-shell microstructures are highly promising to be used as electrode materials in supercapacitors and other energy storage devices.     

无患子皂苷的复配及其在构筑Ni(OH)2/NiOOH复合材料中的应用

以无患子为原料,提取得到天然表面活性剂无患子皂苷,研究其与阳离子表面活性剂十六烷基三甲基溴化胺（CTAB）的复配性能,并将无患子皂苷和复配表面活性剂用于溶剂热法制备氢氧化镍复合材料。考察了反应溶剂、温度和表面活性剂对材料形貌的影响。研究表明：复配体系具有优异协同增效作用,当无患子皂苷与CTAB以质量比50：50复配时,表面活性剂溶液的临界胶束浓度（CMC）及临界胶束浓度下对应表面张力（γ_CMC）分别由无患子皂苷的1 g/L和41.97 mN/m大幅度降低到0.18 g/L和24.63 mN/m。对氢氧化镍复合材料的形貌分析及XRD分析结果显示：在乙醇体系中,以无患子皂苷为表面活性剂,180℃时制得形貌均匀的具有孔隙花球状微球结构复合材料,其纳米片多且厚;以无患子皂苷/CTAB复配体系为表面活性剂,在乙醇体系中,140℃制得形貌均匀的珊瑚球形复合微纳米材料;两种不同形状的氢氧化镍复合材料均为Ni（OH）₂/NiOOH型复合材料。     

PREPARATION OF PEROVSKITE 0.75Pb(Ni1/3Nb2/3)O3-0.25PbTiO3 CERAMICS USING SEMICHEMICAL METHODS AND RELATED REACTION MECHANISMS

This article discusses a mechanism for preparing perovskite powders, 0.75Pb(Ni_1/3Nb_2/3)O₃-0.25PbTiO₃ (PNN-PT), using a semichemical method (SCM).Precursors were prepared by adding aqueous Ni(Ac)₂ solutions to an alcohol slurry of PbO, Nb₂O₅, and TiO₂. The TG-DTG and DSC analysis of the precursors and XRD analysis of the powders at different thermal treatment temperatures showed that the reaction mechanisms in this method differ from those in the conventional mixed-oxide method. The aqueous Ni(Ac)₂ solution reacted with PbO to form Pb(Ac)₂ · Pb(OH)₂ · H₂O and Ni(OH)₂, which decomposed to form nascent PbO and NiO, thereby improving the reactivity and distribution of PbO and NiO. Pb₃Nb₂O₈ and NiNb₂O₆ formed and were easily converted into the perovskite phase during the thermal treatment process. At a thermal treatment temperature of 850°C, the content of the perovskite phase reached 98%. Pyrochlore-free PNN-PT ceramic was obtained after 2 h of sintering at 1100°C, and its dielectric properties were found to be excellent at temperatures ranging between -55 and 120°C.     

Performance improvement of pasted nickel electrodes with an addition of ball-milled nickel hydroxide powder

Spherical β-Ni(OH)₂ was modified by a low-cost method of normal ball milling (NBM), and the physical properties of both ball-milled and un-milled Ni(OH)₂ were characterized by transmission electron microscopy, specific surface area, particle size distribution and X-ray diffraction. It was found that NBM could obviously increase the surface area, decrease the particle and crystallite size, and reduce the crystallinity of β-Ni(OH)₂, which were advantageous to the improvement of the electrochemical activity of Ni(OH)₂. NBM also lowered the packing density and flowability of Ni(OH)₂, as revealed by the measurements of tapping density and angle of repose. Electrochemical performances of pasted nickel electrodes with an addition of ball-milled Ni(OH)₂ to spherical Ni(OH)₂ as the active material were investigated, and were compared with those of the pure spherical Ni(OH)₂ electrodes. Charge/discharge tests showed that ball-milled Ni(OH)₂ addition could enhance the charging efficiency, specific discharge capacity, discharge voltage and high-rate capability of the electrodes. This performance improvement could be attributed to a more compact electrode microstructure, better reaction reversibility and lower electrochemical impedance, as indicated by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Thus, it was an effective method to modify the microstructure and improve the electrochemical properties of pasted nickel electrodes by adding an appropriate amount of ball-milled Ni(OH)₂ to spherical Ni(OH)₂ as the active material.