具有结晶孔壁介孔镁锌氧复合物(英文)

以介孔碳为硬模板经过二次填充制备了介孔镁锌氧复合物.采用X射线衍射(XRD),透射电镜(TEM),扫描电镜(SEM),N2吸附脱附等手段对材料的结构及形貌进行了表征.结果表明,所制备的材料在具有高有序介孔结构的同时还具有结晶的孔壁.孔径尺寸均为4.0nm,比表面积均为114.5m2.g-1.广角XRD结果初步表明,材料中氧化镁和氧化锌复合形成了固溶体.该材料作为一种半导体材料有望在光学器件领域获得新的应用价值.     

Synthesis and microwave absorbing properties of highly ordered mesoporous crystalline NiFe2O4

Highly ordered mesoporous NiFe(2)O(4) with excellent microwave absorption properties has been synthesized by using mesoporous silica (KIT-6) as a hard template.     

简易模板法制备有序介孔碳

通过一种简易的模板法制备了有序介孔碳,即硅/P123三嵌段共聚物复合物经硫酸处理后,再加入蔗糖碳源经碳化和除硅处理合成出有序介孔碳。该方法与传统硬模板相比,其合成工序简单,成本更低;与其他简化合成方法相比,避免了由碳源不足而造成的介孔碳有序性低的缺点。通过小角XRD、N2吸脱附和HRTEM对样品及其中间过程进行了表征。结果表明,自晶化过程后,样品在合成的各个时期均保持着有序的介孔结构,当蔗糖添加量为1.5g时合成出的介孔碳材料有序性最高,比表面积和孔容也最高,分别为1261m2·g-1,1.03cm3·g-1。     

Synthesis of highly ordered mesoporous crystalline WS(2) and MoS(2) via a high-temperature reductive sulfuration route

A high-temperature reductive sulfuration method is demonstrated to synthesize highly ordered mesoporous metal sulfide crystallites by using mesoporous silica as hard templates. H2S gas is utilized as a sulfuration agent to in situ convert phosphotungstic acid H3PW12O40.6H2O to hexagonal WS2 crystallites in the silica nanochannels at 600 degrees C. Upon etching silica, mesoporous, layered WS2 nanocrystal arrays are produced with a yield as high as 96 wt %. XRD, nitrogen sorption, SEM, and TEM results reveal that the WS2 products replicated from the mesoporous silica SBA-15 hard template possess highly ordered hexagonal mesostructure (space group, p6mm) and rodlike morphology, analogous to the mother template. The S-W-S trilayers of the WS2 nanocrystals are partially oriented, parallel to the mesochannels of the SBA-15 template. This orientation is related with the reduction of the high-energy layer edges in layered metal dichalcogenides and the confinement in anisotropic nanochannels. The mesostructure can be 3-D cubic bicontinuous if KIT-6 (Iad) is used as a hard template. Mesoporous WS2 replicas have large surface areas (105-120 m2/g), pore volumes ( approximately 0.20 cm3/g), and narrow pore size distributions ( approximately 4.8 nm). By one-step nanocasting with the H3PMo12O40.6H2O (PMA) precursor into the mesochannels of SBA-15 or KIT-6 hard template, highly ordered mesoporous MoS2 layered crystallites with the 2-D hexagonal (p6mm) and 3-D bicontinuous cubic (Iad) structures can also be prepared via this high-temperature reductive sulfuration route. When the loading amount of PMA precursor is low, multiwalled MoS2 nanotubes with 5-7 nm in diameter can be obtained. The high-temperature reductive sulfuration method is a general strategy and can be extended to synthesize mesoporous CdS crystals and other metal sulfides.     

Sodium niobate adsorbents doped with tantalum (TaV) for the removal of bivalent radioactive ions in waste waters

Mesoporous silica containing a large amount of isolated Ti was prepared from an alkoxytitanosiloxane precursor through a hard template method. Isopropoxytris(tris-tert-butoxysiloxy)titanium (((i)PrO)Ti[OSi(O(t)Bu)(3)](3), TS3) was synthesized and TS3 was mixed with mesoporous carbon (CMK-3), a hard template. The mixture was pyrolyzed at 180 °C to form a composite consisting of titanosilica and the hard template. After calcination at 600 °C for the removal of the carbon template, the titanium species were not transformed to anatase TiO(2), proved by DR-UV-Vis, FTIR, XPS, and XRD, while the ESR results indicated the presence of isolated Ti. The mesoporous structure was verified by SEM, TEM, and N(2) adsorption. The Si/Ti ratio of the product was consistent with that of the precursor. All the results show that the material prepared from the precursor is ordered mesoporous silica containing a large amount of isolated Ti in the frameworks. The use of well-defined alkoxytitanosiloxane precursor leads to the formation of mesoporous silica with exactly controlled composition of titanium with neither loss of Ti nor transformation to anatase.     

Synthesis of Olive‐Shaped Mesoporous Platinum Nanoparticles (MPNs) with a Hard‐Templating Method Using Mesoporous Silica (SBA‐15)

Well‐ordered mesoporous Pt nanoparticles (MPNs) with uniform olive shapes are synthesized by using two‐dimensional (2D) hexagonal mesoporous silica (SBA‐15) as a hard template. The average particle sizes are controllable in the range of 150 to 230 nm by changing the reduction time. Low‐angle XRD profiles for the obtained MPNs show three distinct peaks assignable to the (10), (11), and (20) planes of a highly ordered 2D hexagonal symmetry. From high‐magnification SEM images, periodically arranged Pt nanowires are observed clearly, which are a negative replica of the 2D hexagonally ordered mesoporous silica (SBA‐15). Furthermore, the single crystallinity of the Pt fcc structure coherently extends over the whole particles. As a result of such unique character as well as high surface area, the obtained MPNs show distinctly enhanced electrocatalytic properties for methanol oxidation reaction compared to other Pt samples, such as Pt black.     

有序介孔炭的合成及液相有机大分子吸附性能研究

分别采用有序介孔氧化硅SBA-15和NaY分子筛为硬模板合成了系列有序介孔炭OMC和微孔炭CFY. N₂静态吸附测试表明, 所合成的介孔炭具有丰富的介孔结构和集中的介孔分布. 以亚甲基蓝为探针分子, 研究其在有序介孔炭OMC和微孔炭CFY上的吸附行为. 研究结果表明, 有序介孔炭中大于3.5 nm的大介孔孔容是决定亚甲基蓝吸附容量和吸附速率的关键因素. 吸附动力学理论研究表明, 准二级动力学方程可以很好地描述亚甲基蓝分子在介孔炭上吸附动力学行为.     

Synthesis of Ordered Mesoporous Carbon Materials by Dry Etching

A novel synthesis method for ordered mesoporous carbons is presented. The inverse replication of a silica template was achieved using the carbonization of sucrose within mesoporous KIT‐6. Instead of liquid acid etching, as in classical nanocasting, a novel dry chlorine etching procedure for template removal is presented for the first time. The resultant ordered mesostructured carbon material outperforms carbons obtained by conventional hard templating with respect to high specific micro‐ and mesopore volumes (0.6 and 1.6 cm³ g^?1, respectively), due to the presence of a hierarchical pore system. A high specific surface area of 1671 m² g^?1 was achieved, rendering this synthesis route a highly convenient method to produce ordered mesoporous carbons.     

Gemini表面活性剂联接基团对合成硅基介孔材料结构的影响

考察了Gemini表面活性剂不同联接基团对介孔结构的影响, 通过改变联接基团碳链的长度和在联接基团中加入苯基和羟基改变链的柔性和亲水性, 可改变表面活性剂在两相界面的头基面积和电荷分布, 形成不同的表面活性剂溶液结构, 并通过自组装过程控制生成不同介孔材料的孔结构. 当联接基团链长为4~8个碳时, 得到六方相孔道结构, 而当碳链长度增加为10~12个碳时, 形成立方相孔道结构, 其中以GEM16-6-16为模板, 形成了高度有序的MCM-41, 以GEM16-12-16为模板, 则得到高度有序的MCM-48. GEM16-3(OH)-16可合成出层状结构, 但有序性较低. GEM16-(1-Ar-1)-16的cmc较低, 在水溶液中溶解度极低, 当加入共溶剂乙醇时, 得到了空心球结构.     

A Study on the Growth of Cr2O3 in Ordered Mesoporous Silica and Its Replication

A systematic study on the growth of Cr₂O₃ in three‐dimensional cubic ordered mesoporous silica (KIT‐6) and its replication through nanocasting is reported. By changing the loading time and amount of precursor, the size and shape of the obtained replica could be controlled to some extent. More interestingly, in contrast to previously published studies, when KIT‐6 with an aging temperature of 100 °C, which has a high degree of interconnectivity, was used as a hard template, a cubic ordered mesoporous Cr₂O₃ replica with an open uncoupled subframework structure and reduced symmetry was obtained. Formation of a replica with different symmetry and uncoupled subframework structure is not only related to the degree of interconnectivity of the parent, but also strongly depends on the type of metal oxide and its growth mechanism in the silica template. Nanocasting of Cr₂O₃ with a low loading results in a replica with monomodal pore size distribution that has same symmetry as the hard template, whereas increasing the loading amount alters the symmetry of the replica and yields a replica with bimodal distribution.     

复合模板剂下有序介孔TiO2的制备研究

在复合模板剂聚氧乙烯十二烷基醚(Brij35）和聚乙二醇（PEG)下，制备出有序介孔TiO2.用XRD、HRTEM、SEM、FT-IR和N2吸附脱附等方法进行表征；并通过对反应过程中电导率和粘度的连续监测，分析有序介孔TiO2形成过程.研究表明,介孔TiO2为规整的六方排列结构，在低于400 ℃焙烧，有序结构稳定性高，比表面积达252 m2•g－1，孔径3.4 nm，晶型为锐钛矿；经500 ℃焙烧，有序介孔结构破坏，并开始出现金红石型晶相.有序介孔TiO2形成过程是基于在高极性介质中非极性的碳氢链聚集成为胶束，同时钛酸丁酯（TBOT）在已形成的胶束上聚集，在酸作用下不断水解缩聚而形成有序介孔结构，有效控制水解和聚合过程是控制介孔材料结构形成的关键.     

Partially graphitized ordered mesoporous carbons for high-rate supercapacitors

Partially graphitized ordered mesoporous carbons have been prepared with a soft template method using low-molecular-weight phenolic resol as a carbon source, triblock copolymer F127 as a template, and ferric citrate as a graphitization catalyst. N₂ sorption and transmission electron microscopy analysis show that the ordered mesoporous carbons have been partially graphitized when the carbonization temperature is above 700 °C. The graphitic ordered mesoporous carbons exhibit better rate performance than amorphous ordered mesoporous carbons. The specific capacitance of the graphitic ordered mesoporous carbons (GOMCs) prepared at 700 °C reaches to 112 F g^?1 at a scan rate of up to 1,000 mV s^?1. Its capacitance retention ratio is 64 %, which is much higher than that of the amorphous ordered mesoporous carbons prepared at 600 °C (33 %). High electronic conductivity and ordered mesoporous structure lead to the high electrochemical performance of the partially graphitized ordered mesoporous carbons.     

Ordered mesoporous Co3O4 as highly active catalyst for low temperature CO-oxidation

Cubic ordered mesoporous Co(3)O(4), prepared via the nanocasting pathway using KIT-6 as hard template, was found to be an excellent catalyst for low temperature CO oxidation, with the activity clearly depending on surface area and pore systems of the catalysts.     

Highly Crystalline Mesoporous C60 with Ordered Pores: A Class of Nanomaterials for Energy Applications

Highly ordered mesoporous C₆₀ with a well‐ordered porous structure and a high crystallinity is prepared through the nanohard templating method using a saturated solution of C₆₀ in 1‐chloronaphthalene (51 mg mL^?1) as a C₆₀ precursor and SBA‐15 as a hard template. The high solubility of C₆₀ in 1‐chloronaphthalene helps not only to encapsulate a huge amount of the C₆₀ into the mesopores of the template but also supports the oligomerization of C₆₀ and the formation of crystalline walls made of C₆₀. The obtained mesoporous C₆₀ exhibits a rod‐shaped morphology, a high specific surface area (680 m² g^?1), tuneable pores, and a highly crystalline wall structure. This exciting ordered mesoporous C₆₀ offers high supercapacitive performance and a high selectivity to H₂O₂ production and methanol tolerance for ORR. This simple strategy could be adopted to make a series of mesoporous fullerenes with different structures and carbon atoms as a new class of energy materials.     

三维有序介孔/大孔TiO2微球的制备、表征及光催化性能

以聚甲基丙烯酸甲酯微球为模板,分别以钛酸四丁酯和四异丙醇钛为钛源,通过溶胶-凝胶法辅助模板法制得TiO2纳米微球前驱体,并用程序升温控制其焙烧温度,最终成功制得了具有三维有序介孔/大孔复合结构的TiO2微球.以罗丹明B(RhB)为模型污染物,探索了以不同钛源制备得到的介孔/大孔复合TiO2微球的光催化性能;并采用XRD、SEM、TEM、UV-vis DRS、比表面积测试、光催化性能测试等对样品的晶粒尺寸、物相、形貌、光吸收、比表面积及性能等进行了分析.结果表明,运用溶胶凝胶法辅助模板法能够合成结晶度高、形貌规整、比表面积大、光催化活性良好的锐钛矿相TiO2微球.     

Synthesis of a new ordered mesoporous NiMoO4 complex oxide and its efficient catalytic performance for oxidative dehydrogenation of propane

Highly ordered mesoporous NiMoO4material was successfully synthesized using mesoporous silica KIT-6 as hard template via vacuum nanocasting method. The structure was characterized by means of XRD, TEM, N2adsorption-desorption, Raman and FT-IR. The mesoporous NiMoO4with the coexistence of α-NiMoO4and β-NiMoO4showed well-ordered mesoporous structure, a bimodal pore size distribution and crystalline framework. The catalytic performance of NiMoO4was investigated for oxidative dehydrogenation of propane. It is demonstrated that the mesoporous NiMoO4catalyst with more surface active oxygen species showed better catalytic performance in oxidative dehydrogenation of propane in comparison with bulk NiMoO4.     

阿拉伯糖基有序介孔碳修饰电极检测盐酸奈福泮的研究

以阿拉伯糖为碳源,介孔硅(SBA-15)为模板剂,用硬模板法制备有序介孔碳材料,采用场发射扫描电镜(Scanning Electron Microscopy,SEM)、透射电子显微镜(Transmission Electron Microscope,TEM)、全自动比表面及孔隙度分析仪(Brunner Emmet Te...     

真空辅助硬模板法制备三维有序介孔氧化钕

以介孔氧化硅KIT-6为硬模板,硝酸钕为金属源,分别在搅拌条件和真空条件下制备具有三维介孔结构的立方多晶氧化钕。采用XRD、TEM和氮气吸附-脱附技术对所得样品进行表征。结果表明,在真空辅助条件下制备所得的氧化钕较在搅拌条件下制备得到的氧化钕具有更规则的三维有序介孔结构,两者的比表面积分别为117和84 m.2g-1。     

A strategy for the synthesis of mesostructured metal oxides with lower oxidation states

A detailed study on the pseudomorphic conversion of ordered mesoporous Co(3)O(4) and ferrihydrite into CoO and Fe(3)O(4), respectively, by using alcohol/water vapor as a gentle reducing agent is described. The reduction conditions for the transformation were optimized. In addition, the first one-pot synthesis of mesostructured CoO by using nanocasting with cubic ordered silica as a hard template is demonstrated.     

超薄骨架有序介孔CdS/NiS的制备及光催化产氢性能

采用有序介孔氧化硅为硬模板, 通过纳米浇筑法制备了由螺旋骨架构建的有序介孔硫化镉(CdS)光 催化材料. 该光催化材料具有约5 nm厚的超薄骨架和大的比表面积(238 m²/g), 能有效缩短光催化反应中 光生电荷迁移到表面进行反应的距离并同时提供更多的反应活性位点, 从而增强光催化性能. 通过原位化学沉积法将不同量的助催化剂硫化镍(NiS)沉积到有序介孔CdS表面, 得到了一系列超薄骨架有序介孔CdS/NiS复合光催化材料. 可见光照射下的光催化产氢活性测试结果表明, 负载适量NiS的有序介孔CdS具有显著增强的光催化产氢活性(3.84 mmol?h^-1?g^-1), 约为负载相同量NiS的普通商业化CdS材料(0.22 mmol?h^-1?g^-1)的17.5倍.