胶体晶体模板法制备三维有序大孔复合氧化物*

胶体晶体模板法是制备三维有序大孔（3DOM）复合氧化物材料的有效方法。制备过程一般包括3个步骤：首先,将单分散微球堆积成三维有序排列的胶体晶体;其次,将液态前驱体填充到胶体晶体的间隙,并在原位转化为固体骨架;最后,将微球去除,在原来微球间的空隙位置得到固体骨架,原来微球占据的位置则成为相互连接的孔穴。其中,胶体晶体模板的组装、前驱体的填充以及模板的去除都是制备3DOM复合氧化物的关键影响因素。本文针对这几个控制因素对胶体晶体模板法制备3DOM复合氧化物的影响进行了概述,并对孔结构的表征以及材料在催化和电极材料等方面的应用作了简单介绍。     

真空填充胶晶模板法快速制备三维有序大孔二氧化钛

以丙烯酸修饰的聚苯乙烯（PS）胶体晶体为模板,采用“三明治-真空”填充法将钛酸四丁酯的乙醇溶液填充到模板间隙中,煅烧除去模板快速高效制备了表面无覆盖层的三维有序大孔二氧化钛（3DOM TiO2）材料。 制备的3DOM TiO2具有典型的反蛋白石结构,孔壁完整且孔径大小均匀,呈六方密堆积的FCC结构。 其孔径为230 nm左右,收缩率仅为14%,孔与孔之间由小窗口相连。 XRD分析表明,500 ℃下煅烧制备的3DOM TiO2为锐钛矿晶型。     

模板法制备三维有序大孔CeO2

以聚苯乙烯微球(polystyrene microsphere)高速离心组装的胶体晶体为模板,以Ce(NO3)3·6H2O与柠檬酸的螯合物填充模板,经热转化后合成了3DOM CeO2.TG-DTA分析表明加入柠檬酸可提高硝酸铈的热稳定性,规避其低熔点对形成3DOM结构的不利因素.通过SEM观察,制备的3DOM材料大孔六方有序,排列紧凑,孔径250 nm,收缩率约16%.大孔之间由小窗口连通,构成三维交联的孔道体系.XRD测试显示,材料由CeO2的立方晶粒组成,粒径11 nm.     

三维有序大孔氨基功能化材料的制备及其对Cr(Ⅵ)的吸附性能

以聚苯乙烯胶晶为模板,3-氨基-丙基-三乙氧基硅烷和正硅酸乙酯为前驱物,合成了三维有序大孔(3DOM)氨基功能化SiO2-NH2材料. SEM观察表明,合成的3DOM材料具有规则整齐的大孔通孔结构,平均孔径在535～596 nm之间,孔径收缩率为4.8%～14.5%. FTIR分析表明,材料中含有氨基等有机基团. BET分析表明,材料的比表面积为10.2 m2/g. 合成的3DOM SiO2-NH2材料对Cr(Ⅵ)离子的吸附能力随着材料中氨基含量的增加而增大,最大吸附量为4.31 mmol/g.     

葡萄糖氧化酶在氨基功能化三维有序大孔材料上的固定化研究

一类新型功能化三维有序大孔（3DOM）材料被用于固载葡萄糖氧化酶．以聚苯乙烯胶晶为模板,三氨基丙基三乙氧基硅烷和正硅酸乙酯为前驱物,合成了不同氨基含量的3DOM SiO2-NH2材料．并以戊二醛为交联剂,成功地在3DOM SiO2-NH2材料表面嫁接了葡萄糖氧化酶,所得材料具有较高的催化活性．SEM观察表明,3DOM SiO2-NH2材料具有规则整齐相通的大孔孔道结构．FTIR测试表明材料中含有氨基及有机基团,戊二醛及葡萄糖氧化酶以C=N键嫁接在3DOM材料孔壁表面．     

三维有序大孔钙钛矿 LaFeO3 催化剂的制备及其催化炭黑颗粒燃烧性能

 采用水油两相双引发剂的无皂乳液聚合法制备了羧基改性的聚甲基丙烯酸甲酯 (PMMA) 聚合物微球, 并以此为模板, 采用胶体晶体模板法制备了三维有序大孔 (3DOM) 钙钛矿 LaFeO3 催化剂. 同时采用柠檬酸络合燃烧法制备了纳米钙钛矿 LaFeO3 催化剂. 通过傅里叶红外光谱、扫描电镜、X 射线衍射和激光粒度仪等方法对样品进行了表征. 采用程序升温氧化反应评价了催化剂对模拟柴油机炭黑颗粒催化燃烧的活性. 结果表明, 制备的羧基改性 PMMA 聚合物微球固含量约为 10%, 表面羧基含量约为 3 mmol/g. 微球粒径分布均匀, 且可通过调节反应条件得到不同的粒径, 可控范围在 300~700 nm. 所制得的 3DOM 钙钛矿 LaFeO3 催化剂以六方有序的方式排列, 其孔径及孔径收缩率分别为 300 nm 和 32%, 大孔孔壁平均厚度约 50 nm. 该催化剂对炭黑颗粒催化燃烧的 T10, T50, T90 和 SmCO2 分别为 340, 412, 458 oC 和 99.8%, 性能优于纳米 LaFeO3 催化剂.     

含稀土铕配合物三维有序大孔材料的制备及其荧光性能

采用物理吸附的方法将稀土配合物嵌入三维有序大孔聚合物材料的孔内,组装了发光性能良好的含邻菲罗林-铕配合物的三维有序大孔聚合物材料(3DOM/Eu(Phen)2).并通过扫描电镜、红外光谱和荧光光谱对3DOM/Eu(Phen)2组装体进行了表征.结果表明:组装体的结构保持了三维有序大孔材料的结构特征,在紫外灯的照射下,发出稀土离子的特征谱线,与纯配合物相比,其激发光谱发生蓝移,荧光寿命延长.     

作为锂离子电池负极材料的三维有序大孔SnO2的 制备及表征

通过聚苯乙烯(PS)胶晶模板法合成了三维有序大孔(3DOM) SnO2. 运用扫描电镜、热重分析、X射线衍射、电化学充放电等多种方法对其结构和性能进行了表征和研究. SEM图表明PS胶晶模板微球排列规整, 大小均匀(直径275±10 nm), 形成多层六方紧密堆积排列; 煅烧除去模板后的3DOM SnO2呈三维多孔网络结构, 具有圆型和六边形的孔隙形貌, 其孔径大小为(215±10) nm; 孔壁由SnO2纳米晶粒组成, 壁厚为20～30 nm. XRD图谱表明经过煅烧除去模板后, 形成了纯SnO2相. 当作为锂离子电池负极材料时, 3DOM SnO2表现出较好的充放电容量和库仑效率. 此外, 这种合成方法简单、经济, 可进一步应用于其它锂离子电池材料的合成.     

三维有序大孔复合材料Ag/TiO2的制备与不同模式下的光催化性能

采用聚苯乙烯(PS)微球和EO20PO70EO20(P123)作为模板剂,通过溶胶-凝胶及煅烧后处理等方法制备了三维有序大孔复合材料Ag/TiO2(3DOM Ag/TiO2).经傅里叶变换红外光谱、X射线衍射、紫外-可见漫反射吸收光谱、X射线光电子能谱、N2吸附-脱附测试和扫描电子显微镜配合X射线能量色散谱等测试手段对其组成、结构及形貌等进行了表征.结果显示,该复合材料的孔结构排列整齐有序,孔壁呈现介孔结构且分布均匀,属于三维有序大孔材料.该3DOM Ag/TiO2具有锐钛矿晶相,其Ag以单质形式存在.与商用光催化剂(Degussa P-25)相比,3DOM Ag/TiO2对光的吸收红移至可见区.考察了3DOM Ag/TiO2在紫外光、可见光以及微波辅助等不同模式下光催化降解有机污染物的性能.结果显示,其活性明显高于P-25和Ag/TiO2,且针对不同类型的有机污染物均表现出较好的光催化性能.     

有序大孔材料的制备及其应用

本文综述了近年来有序大孔材料的制备及应用.有序大孔材料的制备方法有胶态晶体模板法、生物模板法及其它模板法,重点阐述了用胶态晶体为模板制备有序大孔材料,如大孔金属、大孔无机氧化物、大孔碳、大孔半导体、大孔无机盐、大孔碳/无机氧化物复合物和大孔有机聚合物.用胶态晶体为模板制备有序大孔材料在催化、吸附、分离、传感器、光子晶体和声学等领域有潜在的应用.     

Highly crystalline inverse opal transition metal oxides via a combined assembly of soft and hard chemistries

A combined assembly of soft and hard chemistries is employed to generate highly crystalline three-dimensionally ordered macroporous (3DOM) niobia (Nb2O5) and titania (TiO2) structures by colloidal crystal templating. Polystyrene spheres with sp2 hybridized carbon are used in a reverse-template infiltration technique based on the aqueous liquid phase deposition of the metal oxide in the interstitial spaces of a colloidal assembly. Heating under inert atmosphere as high as 900 degrees C converts the polymer into sturdy carbon that acts as a scaffold and keeps the macropores open while the oxides crystallize. Using X-ray diffraction it is demonstrated that for both oxides this approach leads to highly crystalline materials while heat treatments to lower temperatures commonly used for polymer colloidal templating, in particular for niobia, results in only weakly crystallized materials. Furthermore it is demonstrated that heat treatment directly to higher temperatures without generating the carbon scaffold leads to a collapse of the macrostructure. The approach should in principle be applicable to other 3DOM materials that require heat treatments to higher temperatures.     

Porous Hybrid Photocatalysts Based on Polyoxometalates

This paper reviews a series of new and water-tolerant porous POM-containing hybrid photocatalysts with different pore sizes. These materials were prepared by soft chemical synthesis techniques including sol-gel chemistry, intercalation chemistry, colloidal crystal templating, cluster chemistry, and hydrothermal process. We also report the heterogeneous photocatalytic behaviors of these as-prepared materials, including activity, kinetics, and reaction mechanism.     

Synthesis and electrochemical performance of three-dimensionally ordered macroporous LiCoO2

Three-dimensionally ordered macroporous (3DOM) LiCoO₂ was synthesized by colloidal crystal templating method using poly(methyl methacrylate) with the diameter of 232 nm as the template. The effects of roasting temperature on properties of LiCoO₂ cathode materials were investigated by thermogravimetric analysis (TG-DTG), scanning electron microscope, X-ray diffraction, transmission electron microscopy, and electrochemical measurements. The results indicated that the synthesized 3DOM LiCoO₂ calcined at 700 °C had better crystal framework and electrochemical properties. The 3DOM LiCoO₂ samples presented higher rate capacity compared to commercial LiCoO₂ with a specific discharge capacity of 151.2 mAh g^?1 at a current density of 1 C, and 92 % of the specific discharge capacity was retained after 50 charge–discharge cycling.     

Three‐Dimensionally Ordered Macroporous Nitroxide Polymer Brush Electrodes Prepared by Surface‐Initiated Atom Transfer Polymerization for Organic Radical Batteries

The synthesis and electrochemical performance of three‐dimensionally ordered macroporous (3DOM) nitroxide polymer brush electrodes for organic radical batteries are reported. The 3DOM electrodes are synthesized via polystyrene colloidal crystal templating with electropolymerization of polypyrrole, modification of surface initiator, and surface‐initiated atom transfer radical polymerization. The discharge capacity of the 3DOM electrodes is proportional to the thickness of the inverse opal. The discharge capacity of the 3DOM electrode at a discharge rate of 5 C is 40 times higher than that of the planar electrode; its cycle‐life performance exhibits 96.1% retention after 250 cycles.     

Immobilization of Glucose Oxidase on Ordered Macroporous Silicas Functionalized with Amino Group

A novel glucose oxidase immobilized on three‐dimensionally ordered macroporous (3DOM) material has been prepared by firstly preparation of hybrid 3DOM SiO₂‐NH₂ materials using colloidal crystal method, and following covalent immobilization of glucose oxidase on the pore walls of the 3DOM materials. The materials were characterized by SEM, FTIR, DSC and BET techniques. SEM observation shows that the macropores are highly ordered and are interconnected by small windows. FTIR measurement shows that there are amino and organic groups in the pore walls. The surface area of the 3DOM SiO₂‐NH₂ material is about 10.2 m²/g. The loaded amount of enzyme is increased with amino content in the materials. The immobilized enzyme has high activity, thermal stability and can be reused.     

New directions in self-assembly:: materials synthesis over ‘all’ length scales

Recent advances in self-assembly include novel synthetic pathways to well-ordered porous materials with channel and cavity dimensions that traverse multiple length scales. A creative amalgamation of surfactant and colloidal crystal templating methods together with microfabrication techniques allow unprecedented control over the organization of inorganic and organic building units and the construction of angstrom to millimeter composite architectures. These structurally and topologically complex solids display hierarchical building principles and properties that transcend those of the individual components. Possible utility for materials of this genre include, fuel cell electrodes, solid state battery electrolytes and plasticizers, chemical sensors, photovoltaics, bone implants, membranes, chromatography supports and chemical delivery systems.     

三维有序大孔α-Fe2O3的制备及电化学性能研究

通过聚苯乙烯(PS)胶晶模板法合成了三维有序大孔(3DOM) α-Fe2O3, 运用扫描电镜、热重分析、X射线衍射、电化学充放电等多种方法对其结构和性能进行了表征和研究. SEM表明PS 胶晶模板和3DOM α-Fe2O3呈周期性排列. 合成的3DOM α-Fe2O3为三维有序多孔网状结构, 具有球型和六边形的孔隙形貌, 其孔径大小约为(115±10) nm; 孔壁由α-Fe2O3纳米晶粒组成, 壁厚为20～30 nm. XRD图谱表明经过煅烧除去模板后, 形成了纯α-Fe2O3相. 当3DOM α-Fe2O3作为锂离子电池负极材料时, 首次放电充电容量分别高达1880和1130 mAh•g－1, 20次循环后可逆容量依然高达631 mAh•g－1, 库仑效率大于90%.