超声化学技术合成MnO2/MoS2纳米交互积层材料

层状氧化锰在氢氧化四甲基胺溶液中超声处理20分钟后，层状氧化锰剥离成纳米层胶体分散液。层状LiMoS₂在超声条件下浸入到10^-4M HNO₃溶液中，随后将得到的处理液加入到层状氧化锰纳米层胶体分散液中，超声处理合成得到了MnO₂/MoS₂纳米交互积层材料，提出了相同电性无机纳米层间超声化学合成新型交互积层材料新技术。     

二氧化锰纳米层的制备及电容性能研究

以Mn(NO3)2、Na OH和H2O2为原料,采用水热技术制备了Na型层状氧化锰(Na-Mn O2)。通过离子交换反应对NaMn O2进行了剥离,得到了氧化锰纳米层胶体分散液。将氧化锰纳米层分散液冷冻干燥后得到了氧化锰重组物(ERMn O2)。通过XRD、SEM和AFM对制备试样进行了分析表征。电化学测试结果表明,在1.0 mol·L-1Na2SO4水溶液中,当电流密度为0.25 A·g-1时,ERMn O2的质量比电容高达117 F·g-1远远高于其前驱物Na-Mn O2的比电容(79 F·g-1),并且表现出相似的循环稳定性。     

高比容量二氧化钌电极材料制备

以无定型Ru O2·x H2O和金属Ru粉末为反应物,采用高温固相反应制备了Na型层状氧化钌(NaRu O2),通过离子交换反应对Na-Ru O2实现了剥离,得到了氧化钌纳米层胶体分散液。将氧化钌纳米层分散液冷冻干燥处理后得到了氧化钌重组物(ERRu O2)。通过XRD和SEM对制备试样进行了分析表征。电化学测试结果表明,在0.5 mol L-1H2SO4水溶液中,当电流密度为0.25 A g-1时,ERRu O2电极比电容高达645 F g-1,远远高于前驱体Ru O2·x H2O的比电容(367 F·g-1),并且ERRu O2电极表现出与前驱物相似的循环稳定性,是一种性能优异的超级电容器电极材料。     

二氧化钛柱撑层状氧化锰微孔材料的合成及表征

Na型层状锰氧化物于0.1 mol/L HCl 溶液中离子交换制得前驱体H型层状锰氧化物. H型层状锰氧化物在十二胺乙醇溶液中反应得到层间距为2.62 nm的中间产物——十二胺插入的层状锰氧化物, 该中间产物在异丙醇钛和乙醇的混合溶液中溶剂热处理得到层间距为1.24 nm的钛酸柱撑层状锰氧化物. 在300 ℃条件下经2 h焙烧得到二氧化钛铸型氧化锰微孔材料. 应用XRD, DSC-TGA, SEM, TEM, IR, 氮气吸附实验及元素分析进行了不同阶段所得试样的分析表征. 结果表明十二胺分子在锰氧层间的最大插入量为2.2 mmol/g, 异丙醇钛分子的置换插入生成了组成为Mn_7.00Ti_1.74O_23.3(C₁₂H₂₅NH₂)_0.52•1.93H₂O的铸型层状锰氧化物. 300 ℃焙烧处理所得二氧化钛铸型氧化锰微孔材料的比表面积为140 m²/g.     

层间距为1.44 nm层状氢氧化苯甲酸锌剥离重组行为研究

层间距为1.44 nm层状氢氧化苯甲酸锌在乙醇、正丙醇、正丁醇介质中可剥离成其基本组成单元纳米层. 用TG-DTA、XRD、SEM、TEM和元素分析等手段研究了剥离的纳米层重组得到样品的结构特征、形貌和化学组成. 结果表明: 水热合成样品和剥离的纳米层重组样品具有相同的层状结构, 它们的化学组成分别为Zn(OH)1.12(C6H5COO)0.88和Zn(OH)1.1(C6H5COO)0.9. 水热合成的纤维状粒子剥离重组后改变成为像纳米带和纳米花粒子形貌.     

维生素C插层的钙铝水滑石的合成及其缓释性能

以钙铝水滑石[Ca2Al(LDH)]为主体,维生素C[VC(C6H8O6)]为客体,采用共沉淀法将VC插层到LDH层间合成了新型VC-无机复合材料{Ca2Al(OH)6[(C6H7O6)0.82(NO3)0.18]·1.7H2O(简称Ca2Al-VC)},其结构和缓释性能经UV-Vis,FT-IR,元素分析,XRD,ICP和TG-DTG表征。研究结果表明,Ca2Al-VC晶型完整,晶相单一,层间距14.6。VC阴离子双层交替垂直于上下层板,插入量为82%;插入到LDH层间的VC热稳定性得到了明显提高,大部分VC的分解发生在442℃附近;VC在高浓度(0.1 mol·L-1)的Na2SO4溶液中释放速度及释放量高于低浓度(0.01 mol·L-1)的Na2SO4溶液;在去离子水中的释放主要靠离子的扩散。     

高温驱动氧化锰刻蚀制备纳米氧化锰-多孔石墨烯及其锂空气电池性能研究

本文通过简单的电荷吸附制备了高分散的氧化石墨烯含锰化合物（Mn-GO）,利用高温驱动下氧化锰的生长以及热运动同时实现了GO的还原、刻蚀和纳米氧化锰的负载,即成功构筑了纳米氧化锰-多孔石墨烯复合材料（MnO-PGNSs）. 对影响GO分散性的Mn²⁺的添加量、影响GO层数的分散液浓度以及影响MnO热运动的烧结条件进行了详细的考察. 研究发现,当Mn-GO同时满足优异的分散性、适合的片层厚度和烧结条件（＞800℃,>2h）,才能在GNSs表面刻蚀成孔制备得到MnO-PGNSs. 本文进一步将MnO-PGNSs作为锂空气电池正极材料,结果表明在50 mA·g^-1的电流密度下深度放电后容量达到5100 mAh·g^-1,相比于GNSs和PGNSs,MnO-PGNSs具有更高的比容量. 锂空气电池性能的提高得益于GNSs表面的多孔结构和MnO优异的催化活性.     

剥离型硅橡胶/黏土纳米复合材料研究

利用层状硅酸盐制备有机 无机纳米复合材料是当前人们研究的热点[1,2 ] ,这类材料具有较常规聚合物 无机填料复合材料无法比拟的优点 ,可以明显改善高分子材料的物理机械性能、热稳定性、气体阻隔性、阻燃性、导电性、光学性等 .一般来说 ,聚合物 层状硅酸盐 (Ｐｏｌｙｍｅｒｌａｙｅｒｅｄｓｉｌｉｃａｔｅ ,ＰＬＳ)纳米复合材料可分为插层型和剥离型两种类型 .插层型纳米复合材料即聚合物插入到硅酸盐层中 ,硅酸盐在近程仍保持原有的有序晶体结构 ,在远程则是无序的 .对弹性体而言 ,硅酸盐含量在插层型杂化材料中的含量比较高 ,力学性能…     

层状纳米光催化复合材料H0.8Fe0.8Ti1.2O4/TiO2的合成及性质

用固相合成法制备出K0.8Fe0.8Ti1.2O4,并用离子交换反应制备出H0.8Fe0.8Ti1.2O4;通过C3H7NH2层间膨胀,TiO2粒子的插入和紫外光分解等反应,合成出一种新的层状光催化纳米复合材料-H0.8Fe0.8Ti1.2O4/TiO2.X射线衍射和漫反射等表征结果表明 该样品的层间高度为0.47nm,禁带能隙为2.18和2.88eV.用(>400 nm的光照射30 min,0.4 g样品可使甲基橙溶液(20 mg/L)的降解率达到22.1%.而同样条件下标准TiO2(P-25)仅为6.2%,表明所研制的层状纳米复合材料具有较高的光催化活性.     

γ—MnO2纳米晶的水热合成及表征

过渡金属Ni、Co、Fe、Mn的氧化物材料因其具有特异的光、电、热、磁等性质，是材料科学研究与探索的一个重要方向之一[1~3]，而该系列氧化物的纳米材料因其具有诸多优异的物理化学特性，近年来已引起材料科学研究工作者的极大兴趣[1~5]．本文采用水热法成功地合成出γ－MnO2纳米超微粒子，并对其热敏特性进行了测试，获得满意的结果．1实验部分1．1样品的制备将浓度为3％H2O2溶液50mL，在充分搅拌条件下逐滴加入到盛有100mL浓度为1．25％的KMnO4溶液的聚四氟乙烯容器中，进行氧化还原反应，得到较稳定的棕色MnO2水合物胶体（放置3h无…     

Redoxable nanosheet crystallites of MnO2 derived via delamination of a layered manganese oxide

This paper reports on the swelling and exfoliation behavior of a layered protonic manganese oxide, H(0.13)MnO(2).0.7H(2)O, in a solution of tetrabutylammonium (TBA) hydroxide and the formation and characterizations of unilamellar two-dimensional crystallites of MnO(2). At low doses of TBA ions, layered manganese oxide was observed to undergo normal intercalation, yielding a TBA intercalated phase with a gallery height of 1.25 nm. With a large excess of TBA ions, osmotic swelling occurred, giving rise to a very large intersheet separation of 3.5-7 nm. In an intermediate TBA concentration range, the sample exhibited a broad X-ray diffraction profile with superimposed diffraction features due to intercalation and osmotic swelling. The component responsible for the broad profile was isolated by centrifuging the mixture twice at different speeds, and the recovered colloid was identified as a pile of MnO(2) nanosheets, corresponding to the individual host layer of the precursor layered manganese oxide. Observations by transmission electron microscopy and atomic force microscopy revealed high two-dimensional anisotropy with a lateral dimension of submicrometers and a thickness of approximately 0.8 nm. The nanosheet exhibited broad optical absorption with a peak at 374 nm (epsilon = 1.13 x 10(4) mol(-1) dm(3) cm(-1)). The restacking process of the colloidal MnO(2) nanosheets was followed by aging the colloid at a relative humidity of 95%. The broad diffraction pattern due to the exfoliated sheets weakened with time and eventually resolved into two sharp distinct profiles attributable to a TBA intercalation compound with an intersheet spacing of 1.72 nm and an osmotically swollen hydrate with >10 nm at a very early stage. As drying progressed, the former phase became more abundant without a change in interlayer distance, while the degree of swelling of the latter phase gradually decreased to 2.7 nm that remained unchanged on further aging. Subsequent drying at a lower humidity collapsed the 2.7 nm phase. The resulting single 1.72 nm phase was dehydrated by heating at 150 degrees C to produce a phase with a contracted interlayer spacing of 1.3 nm.     

A designed single-step method for synthesis and structural study of organic-inorganic hybrid materials: well-ordered layered manganese oxide nanocomposites

A fast and single-step method was successfully developed toward synthesizing well-ordered organic-inorganic hybrid layered manganese oxide (LMO) nanocomposites and Keggin/organic ions intercalated into layered manganese oxide at room temperature in 1 day. The ordering of layered structures is highly dependent on pH and drying conditions. The Keggin/organic intercalated LMO shows improved thermal stability of the layered structure over that of hybrid LMO.     

Electrodeposition of layered manganese oxide nanocomposites intercalated with strong and weak polyelectrolytes

Multilayered manganese oxide nanocomposites intercalated with strong (poly(diallyldimethylammonium) chloride, PDDA) and weak (poly(allylamine hydrochloride), PAH) polyelectrolytes can be produced on polycrystalline platinum electrode in a thin film form by a simple, one-step electrochemical route. The process involves a potentiostatic oxidation of aqueous Mn2+ ions at around +1.0 V (vs Ag/AgCl) in the presence of polyelectrolytes. Fully charged PDDA polycations are accommodated tightly in the interlayer space by electrostatic interaction with negative charges on the manganese oxide layers, leading to an interlayer distance of 0.97 nm. The layered film prepared with PAH has a larger polymer content (PAH/Mn molar ratio of 0.98) than that (PDDA/Mn molar ratio of 0.43) made with PDDA because of the smaller charging degree of PAH, exhibiting a larger interlayer distance (1.19 nm). The interlayer PAH contains neutral (-NH2) and positively charged (-NH3(+)) amine groups, and the -NH3(+) groups are associated with Cl- (to generate -NH3(+) Cl- ion pairs) as well as the negatively charged manganese oxide layers. Both polyelectrolytes once incorporated were not ion exchanged with small cations in solution. The layered structure of PDDA/MnO(x) was collapsed during the reduction process in a KCl electrolyte solution, accompanying an expansion of the interlayer as a result of incorporation of K+ ions for charge neutrality. On the contrary, the layered PAH/MnO(x) film showed a good electrochemical response due to the redox reaction of Mn3+/Mn4+ couple with no change in the structure. X-ray photoelectron spectroscopy revealed that, in this case, excess negative charges generated on the manganese oxide layers upon reduction can be balanced by the protons being released from the -NH3(+) Cl- sites in the interlayer PAH; the Cl- anions becoming unnecessary are inevitably excluded from the interlayer, and vice versa upon oxidation.     

Preparation and formation mechanism of a n-butylammonium/MnO2 layered hybrid via a one-pot synthesis under moderate conditions

The preparation of organic/inorganic layered hybrids has relied on multistep processing. Thus, shortening the synthetic procedure is important for possible future applications, but only a few studies report one-pot syntheses. In this work, we established a simple one-pot solution process to synthesize layered alkyl ammonium/MnO(2) hybrids, by stirring MnCl(2) and alkyl amine/H(2)O(2) aqueous solutions at 40 °C; the reaction concept is a chemical oxidation of Mn(II) ions in the presence of alkyl amine in aqueous solution. Furthermore, the formation mechanism of the layered n-butylammonium/MnO(2) hybrid was examined by following the structural and optical changes during the reaction, revealing that the one-pot reaction includes 3 steps; formation of β-MnOOH, topotactic oxidation of β-Mn(III)OOH to form the protonated layered manganese oxide H(x)Mn(III, IV)O(2)·yH(2)O, and ion-exchange of interlayer H(+) (or H(3)O(+)) with n-butylammonium to form layered n-butylammonium/MnO(2).     

Synthesis and structural study on MnO2 nanosheet material by X-ray absorption spectroscopic technique

MnO2 nanosheet with acetylene black composite material has been synthesized from layered K0.45MnO2 powder. The electrochemical lithiation reaction of nanosheet composite material proceeds in a different manner from that of the parent material, layered K0.45MnO2 powder. To elucidate the origin of the changes in discharge profile, the electronic and local structures for the nanosheet composites and its parent and protonated material have been investigated by Mn K-edge and O K-edge X-ray absorption spectroscopy (XAS). The results showed that local and electronic structure around Mn ions does not vary during nanosheet formation, while significant changes in electronic structure around oxide ions were observed. Accordingly, it is suggested that the difference observed in discharge profile is due to the electronic structural change induced by nanosheet formation.     

Na-Mn-O正极材料的合成及电化学性能

以Mn(CH3COO)2·4H2O为锰源, 以Na2CO3为钠源, 通过溶液-凝胶法合成干凝胶前驱体, 将前驱体在空气气氛中焙烧得到Na-Mn-O正极材料. 并用傅立叶红外光谱(FT-IR), 热重分析(TG), X射线衍射(XRD), 扫描电镜(SEM), 恒流充放电测试等对材料结构和性能进行研究. 结果表明,600 ℃焙烧的样品为结构稳定的层状锰酸钠, 属于六方层状P2结构, 空间群为P63/mmc, 通过PowderX软件计算得到其晶胞参数为a=0.284 nm, c=1.116 nm. Na-Mn-O正极材料在Li+嵌入和脱出过程中, 部分Na+从层状主晶格中脱出, 使得Li+在MnO6层间的嵌/脱阻力减小(由于Na+(0.095 nm)半径比Li+(0.076 nm)大), 电化学性能明显改善. 在充放电电流密度为25 mA·g-1, 电压在2.0-4.3 V范围时, 600 ℃焙烧的样品第二次放电容量高达176 mAh·g-1, 20次循环后, 容量保持率仍有90.9%.     

Mixed colloidal suspensions of reduced graphene oxide and layered metal oxide nanosheets: useful precursors for the porous nanocomposites and hybrid films of graphene/metal oxide

Homogeneously mixed colloidal suspensions of reduced graphene oxide, or RGO, and layered manganate nanosheets have been synthesized by a simple addition of the exfoliated colloid of RGO into that of layered MnO(2). The obtained mixed colloidal suspensions with the RGO/MnO(2) ratio of ≤0.3 show good colloidal stability without any phase separation and a negatively charged state with a zeta (ζ) potential of -30 to -40?mV. The flocculation of these mixed colloidal suspensions with lithium cations yields porous nanocomposites of Li/RGO-layered MnO(2) with high electrochemical activity and a markedly expanded surface area of around 70-100?m(2) g(-1). Relative to the Li/RGO and Li/layered MnO(2) nanocomposites (≈116 and ≈167?F?g(-1)), the obtained Li/RGO-layered MnO(2) nanocomposites deliver a larger capacitance of approximately 210?F?g(-1) with good cyclability of around 95-97?% up to the 1000th cycle, thus indicating the positive effect of hybridization on the electrode performances of RGO and lithium manganate. Also, an electrophoretic deposition of the mixed colloidal suspensions makes it possible to easily fabricate uniform hybrid films composed of graphene and manganese oxide. The obtained films show a distinct electrochemical activity and a homogeneous distribution of RGO and MnO(2). The present experimental findings clearly demonstrate that the utilization of the mixed colloidal suspensions as precursors provides a facile and universal methodology to synthesize various types of graphene/metal oxide hybrid materials.     

Electrosorption of manganese dioxide on electrochemically modified carbon fiber nonwoven materials

Electrosorption of manganese dioxide on an electrochemically activated carbon fiber nonwoven electrode was studied as influenced by the current density, solution flow-through rate, and concentration of the MnO(OH)₂ colloid solution. It was found that manganese hydroxide can be deposited onto electrochemically activated fibers of fibrous carbon materials by different methods: (1) electrosorption of MnO(OH)₂ from its colloid solution, (2) synthesis of MnO(OH)₂ directly on the fibrous carbon material sample, and (3) impregnation with an MnO(OH)₂ colloid solution.     

Synthesis of hexagonal nickel hydroxide nanosheets by exfoliation of layered nickel hydroxide intercalated with dodecyl sulfate ions

One-nanometer-thick nickel hydroxide nanosheets were prepared by exfoliation of layered nickel hydroxides intercalated with dodecyl sulfate (DS) ions. The shape of the nanosheets was hexagonal, as was that of the layered nickel hydroxides intercalated with DS ions. The nickel hydroxide nanosheets exhibited charge-discharge properties in strong alkaline electrolyte. The morphology of the nanosheet changed during the electrochemical reaction.     

Intercalation compound of diclofenac sodium with layered inorganic compounds as a new drug material

The intercalation reaction of diclofenac sodium (DFS) with layered inorganic compounds, gamma-titanium phosphate (gamma-TiP), proton type titanium oxide (H-TiO2) and sodium type synthetic mica (Na-TSM), was examined on. The direct reaction of DFS in ethanol-water mixed solvent resulted in the large amount accommodation of DFS. The amount of intercalated DFS was the order of gamma-TiP>H-TiO2>Na-TSM corresponding to the order of acidity. The intercalation using phospholiopids was also examined to assist the intercalation reaction. However, the amount of intercalated DFS was rather small in comparison with those in the direct reaction. DFS accommodated in gamma-TiP dissolved into neutral and basic buffer solution stoichiometry while scarcely dissolved in the acidic solution. The mechanism of the intercalation and reverse dissolution was successfully accounted according to the ion-exchange mechanism between Na+ in DFS and H+ in gamma-TiP. The dissolution from tablet of DFS/gamma-TiP intercalation compound was examined by using a disintegrator. It was found that the dissolution rate appropriately controlled by mixing the disintegrator. The present results suggested the different possibilities in the clinical field to use layered inorganic compounds such as drug delivery system (DDS).