银原位改性HMS材料的结构及抗菌性能

采用溶胶凝胶法,以银氨离子为银源,原位合成了含Ag六方介孔硅（Ag-HMS）无机抗菌材料,探讨了其抗菌性能,并利用XRD、FT-IR、TG-DTA、UV-Vis、ESEM、EDS及N₂的吸附/脱附等方法对材料进行了表征。结果表明,材料保持了良好的介孔结构和热稳定性,具有良好的紫外线吸收性能,银物种以骨架态和非骨架态形式存在并且分散均匀;相对于HMS,Ag-HMS材料脱模时的热化学过程、孔体积、介孔有序度、比表面积及粒子形貌均发生了显著改变。在抑菌实验中,Ag-HMS对枯草杆菌(B.subtilis)、大肠杆菌(E.coil)、芽孢杆菌(G.bacillus)及金黄色葡萄球菌(S.aureus)均显示出良好的抗菌性能,其中对枯草杆菌和大肠杆菌尤为显著,当Ag-HMS用量为1.00 mg·L^-1,12 h后即可将两者彻底杀灭。     

六方介孔氧化硅负载磷钨酸的催化性能

采用浸渍法将磷钨酸(HPW)负载于六方介孔氧化硅(HMS)上,制备HPW改性HMS介孔材料HPW/HMS,对其进行了表征;以HPW/HMS为催化剂,催化2-萘甲醚(2-MN)与乙酸酐(AA)的酰化反应,考察了各因素对催化反应的影响. 结果表明,HPW高度分散在HMS上,HPW/HMS的酸量和酸强度随HPW负载量增加而增加. 在温度120℃、时间4 h、催化剂用量0.3 g及2-萘甲醚/乙酸酐摩尔比1:2条件下,2-萘甲醚转化率为75.3%(mol),目标产物2-甲氧基-1-萘乙酮的选择性达83.0%(mol). 催化剂可回收再利用,催化活性略有降低.     

介孔材料催化合成芳酮的应用进展

综述了介孔材料合成芳酮的催化效果及应用进展。着重介绍了几种具有代表性的介孔材料MCM-41、SBA-15、HMS及其改性对芳酮的收率和选择性的影响。芳烃主要有苯环、萘环、杂环化合物,酰化试剂为羧酸、酸酐和酰氯。简述了催化剂失活的原因,结果表明,不同结构的介孔材料对不同的酰化反应具有不同的催化活性。     

疏水性HMS分子筛的制备及水热稳定性

以三甲基氯硅烷和六甲基二硅氮烷为硅烷化试剂,分别采用气相和液相硅烷化法对HMS分子筛进行表面改性制备疏水性HMS分子筛。考察了改性方法、硅烷试剂与分子筛摩尔比、反应温度和时间对硅烷化效果的影响,研究了改性前后HMS的骨架特征、微观结构和疏水性、水热稳定性。结果表明:气相硅烷化法较液相法优势明显,硅烷化程度和效率均较高;在双硅烷化试剂、反应温度90℃、硅烷试剂与分子筛摩尔之比0.8、反应时间8 h等条件下,改性前后HMS的静态水吸附量分别为45.46%和1.38%,疏水性得到明显提高。HMS经硅烷化改性后保持介孔骨架结构和蠕虫状孔道,同时水热稳定性得到有效改善,800℃水蒸气处理6 h后介孔结构仍然存在。     

介孔材料HMS的改性及在催化反应中的应用

六方介孔硅HMS介孔分子筛具有合成方法简单、条件温和、较大孔径、高比表面、水热稳定性高、很强的吸附和扩散能力和丰富的表面羟基等优良性能,可作为载体或催化剂应用于许多有机化学反应中,特别是应用在大分子尺寸的有机反应中。详细地综述了近10年来HMS介孔材料通过单一金属、复合金属和酸碱改性及其改性后HMS在催化反应中的应用,并对其今后的研究方向进行了展望。     

聚乙二醇-介孔二氧化硅复合材料的合成及表征

利用共混法合成了聚乙二醇-介孔二氧化硅有机-无机复合材料.采用XRD、N_2吸附-脱附、SEM、TEM、红外光谱(FTIR)、DSC-TG等对聚乙二醇-介孔二氧化硅复合材料进行了表征.结果表明,聚乙二醇-介孔二氧化硅仍保持了原来的介孔结构,可以均匀地分散到介孔二氧化硅的基质中.PEG是靠氢键吸附在纳米HMS颗粒表面,两者并没有发生化学反应生成新的化合物.所合成的聚合物具有比较好的耐温性能, HMS提高了聚合物的耐热性.     

介孔分子筛载体在油品深度加氢脱硫中的应用研究进展

介孔分子筛材料以其独特的孔道结构和孔径分布、高的比表面积及较好的热稳定性和水热稳定性等特点,近年来被广泛地用作油品深度加氢脱硫催化剂载体.本文系统综述了近年来MCM、HMS、SBA、KIT等系列介孔分子筛载体应用于油品深度加氢脱硫(HDS)的国内外研究现状.重点讨论了金属、氧化物、酸、磷、与其它载体复合等载体改性方式对...     

铁改性HMS分子筛的制备及表征

采用溶胶-凝胶法,以十二胺为模板剂、三氯化铁为铁源,制备了铁改性HMS分子筛(Fe-HMS),利用XRD、TG-DTA、FT-IR、UV-Vis、ESR、ESEM、EDS及N2吸附-脱附测试技术对材料进行了表征.结果表明Fe-HMS材料由圴匀细小的球状纳米粒子组成,分子筛具有良好的介孔结构和热稳定性,铁已进入载体的骨架;分子筛脱模时的热分解及氧化燃烧温度显著降低,红外谱图中802 cm-1及465 cm-1吸收峰强度减弱,而紫外-可见光的吸收性能明显增强,对200～550 nm波段光的吸收达到95%.     

HMS介孔分子筛合成及其在丙烷脱氢制丙烯反应中的应用

分别以正硅酸乙酯和伯胺表面活性剂为原料和模板剂成功制备HMS介孔分子筛，经负载活性组分后得到Pt-Sn/HMS催化剂并将其应用于丙烷脱氢制丙烯反应。探究合成过程中伯胺表面活性剂碳链长度及水和乙醇的比例对HMS介孔分子筛孔结构的影响。XRD和N₂吸附-脱附等分析结果表明，模板剂链长增长时，介孔分子筛孔径、孔壁厚、比表面积及孔容均增大。适当的水/乙醇比例有利于获得更大比表面积和孔体积的介孔分子筛，并表现出更有序的介孔结构。丙烷脱氢制丙烯反应评价和热分析等表征结果表明，HMS介孔分子筛孔道特征直接影响Pt-Sn/HMS催化剂的催化性能。使用孔体积且比表面积较大的HMS样品作为载体制备的脱氢催化剂在丙烷脱氢反应中表现出优异的催化活性。性能最优的Pt-Sn/HMS-0.60-16催化剂上，平均丙烷转化率达到46.5%,平均丙烯选择性为94.1%,反应24 h后积炭量仅为质量分数3.4%。     

磷酸银-介孔炭复合光催化材料性能的研究

采用共沉淀法将介孔炭与磷酸银结合,制备出磷酸银-介孔炭复合光催化材料。利用扫描电子显微镜（SEM）、透射电子显微镜（TEM）和X射线衍射等技术手段对所制备材料进行表征,结果表明随着介孔炭负载量的增大,生成的磷酸银粒子尺寸减小。所制备材料中的磷酸银为立方体型,介孔炭的加入不会影响其晶体结构,可以制得性能稳定的复合材料。采用氮气吸-脱附测试对复合光催化材料进行光催化性能的评价,主要考察了不同介孔炭负载量对材料的光催化性能的影响。同时,通过光催化实验发现,当介孔炭负载量为10%时,所得的磷酸银-介孔炭复合光催化材料光催化效果最佳,并且所制备的复合光催化材料具有再循环使用的能力。     

Highly selective gas-phase oxidation of benzyl alcohol to benzaldehyde over silver-containing hexagonal mesoporous silica

Silver-containing hexagonal mesoporous silica (Ag-HMS) catalysts with different Si/Ag ratios were synthesized by one-pot hydrothermal method for gas-phase selective oxidation of benzyl alcohol to benzaldehyde. The samples were characterized by nitrogen adsorption, X-ray diffraction, scanning electron micrograph, transmission electron micrograph, X-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectra. It was found that the Ag-HMS catalysts with different Ag loadings (0.55-3.50 wt.%) and different Ag particle sizes (5-32 nm) showed a similar level of catalytic property because they possess a similar Ag surface area. The Ag-HMS catalyst with a Ag loading of 2.81 wt.% exhibited excellent catalytic properties at 583 K with a high benzyl alcohol conversion of near 100%, benzaldehyde selectivity of around 96.0%, and benzaldehyde yield of about 96.0%, superior to those of other M-HMS catalysts (M = Co, Ce, La, Cu, Sr, Cd, Ni, Mn, V, and Fe). The enhanced catalytic performance could be attributed to the presence of the Ag surface oxygen species generated via oxygen spillover process. The work would be helpful for the development of novel Ag catalysts for selective oxidation of benzyl alcohol to obtain high quality of benzaldehyde and understanding the catalytic mechanism.     

High performance binder-free reduced graphene oxide nanosheets/Cu foam anode for lithium ion battery

Binder-free combination of reduced graphene oxide with Cu foam (RGO/Cu foam) anode for lithium ion battery was designed and achieved via one-step facile electro-reduction. The as-prepared composite RGO/Cu foam anode were studied in terms of scanning electron microscope (SEM), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR), Raman, galvanostatic charge/discharge, cyclic voltammogram and AC impedance. As expected, graphene oxide nanosheets were indeed successfully electro-reduced to large degree and tightly combined with Cu foam without any additional polymer binder. Moreover, the integrated RGO/Cu foam electrode delivered high reversible capacity of 1196.2 mAh/g at 0.25 A/g, indicating satisfactory electrochemical performances. High Li-storage activity, large surface area, high conductivity of RGO nanosheets and the binder-free combination with porous Cu foam should be jointly responsible for high electrochemical performances.     

Fabrication of Pt–Cu/RGO hybrids and their electrochemical performance for the oxidation of methanol and formic acid in acid media

Pt–Cu/reduced graphene oxide (Pt–Cu/RGO) hybrids with different Pt/Cu ratios were prepared by the reduction of H₂PtCl₆ and CuSO₄ by NaBH₄ in the presence of graphene oxide (GO). The Pt–Cu nanoparticles were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The reduction of GO was verified by ultraviolet–visible absorption spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. Compared to Pt/RGO, the Pt–Cu/RGO hybrids have superior electrocatalytic activity and stability for the oxidation of methanol and formic acid. Thus they should have potential applications in direct methanol and formic acid fuel cells.     

Binder-free combination of large area reduced graphene oxide nanosheets with Cu foil for lithium ion battery anode

Binder-free combination of large area reduced graphene oxide (RGO) nanosheets with Cu foil was designed and achieved via one-step facile electro-reduction reaction. The obtained composite RGO/Cu foil electrode were studied in terms of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), selected area electron diffraction (SAED), Raman, galvanostatic charge/discharge, AC impedance and cyclic voltammetry (CV). As expected, large area RGO nanosheets with micron order of magnitude successfully formed and tightly combined with Cu foil without any additional polymer binders. Furthermore, RGO/Cu foil electrode delivered a reversible discharge capacity of 870.3 mAh/g after 110 cycles, indicating satisfactory cyclic stability and rate performance. High Li-storage activity, eminent conductivity and tight binder-free integration of RGO nanosheets with Cu foil current collector should be responsible for high electrochemical performances.     

Changes in the Peeled Surfaces of Copper Thin Films Deposited on Polyimide Substrates After Heat Treatment

Peel strength between a copper (Cu) thin film and a polyimide (pyromellitic dianhydride-oxydianiline, or PMDA-ODA) substrate is reduced by heat treatment at 150°C in air. In this work, we investigated the peel strength, the morphology of the interface between Cu films and polyimide substrates using optical microscopy and electron microscopy, and chemical change of the interface using Auger electron spectroscopy (AES) and micro X-ray photoelectron spectroscopy (XPS). The analysis showed that CuO “lumps” were present on the peeled surface of PMDA-ODA after heat treatment at 150°C in air. The peeled surfaces of other polyimide substrates were also analyzed: biphenyl dianhydride-para phenylene diamine (BPDA-PDA) and biphenyl dianhydride-oxydianiline (BPDA-ODA). CuO lumps were present on the peeled surface of BPDA-ODA after the heat treatment, but not that of BPDA-PDA. Compared with the adhesion strength for the Cu thin film, the adhesion strength was high for the Cu/PMDA-ODA and Cu/BPDA-ODA laminates, but the adhesion strength was very low for the Cu/BPDA-PDA laminate. This low strength is the reason that CuO lumps were not detected on the peeled surface of the BPDA-PDA substrate. These CuO lumps were related to the adhesion degradation of the Cu/polyimide laminates after the heat treatment.     

Changes in the adhesion strength between copper thin films and polyimide substrates after heat treatment

The adhesion strength between a copper (Cu) thin film and a polyimide [pyromellitic dianhydride-oxydianiline (PMDA-ODA)] substrate is reduced by heat treatment at 150°C in air. In this work, we determined the changes in adhesion strength between Cu films and polyimide substrates using Auger electron spectroscopy (AES), attenuated total reflection Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The analysis showed that the weak boundary layer (WBL) shifted towards the Cu interface as the heat treatment time was increased. To confirm this shift, we looked at two other polyimide substrates: biphenyl dianhydride-p-phenylene diamine (BPDA-PDA) and biphenyl dianhydride-oxydianiline (BPDA-ODA). Comparing the adhesion strength for the Cu thin film, the adhesion strength was high for the Cu/PMDA-ODA and Cu/BPDA-ODA laminates, but very low for the Cu/BPDA-PDA laminate. One of the possible reasons for this behavior could be that the ether moiety between the two benzene rings in ODA is related to the adhesion between a Cu film and an 0₂-plasma-treated polyimide (PI) substrate. The relationship between the adhesion strength and chemical bonding states is also discussed. We conclude that a Cu thin film sputtered onto a PI substrate is apt to peel at the oxidized interface, due to the heat treatment.     

交联菲罗啉负载铜催化剂用于合成三甲基苯醌

烷基取代的苯醌可用作多种生物活性化合物的功能结构单元。提出了一种在温和条件下，用氧气氧化2,3,6-三甲基苯酚（TMP）得到2,3,5-三甲基-1,4-苯醌（TMQ，维生素E前体）的方法。利用Friedel-Crafts烷基化反应，成功制备了一种基于1,10-菲罗啉的交联多孔聚合物负载铜催化剂Cu/PPhen。采用氮气吸附脱附、SEM、FTIR和XPS对催化剂Cu/PPhen-4进行了一系列的表征，获得了催化剂的基本结构特征。并考察了催化剂的加入量、溶剂、氧气压力、反应温度以及反应时间等因素对Cu/PPhen-4催化氧化制备2,3,5-三甲基-1,4-苯醌的影响，得到最佳的工艺条件。当2,3,6-三甲基苯酚的加入量为136 mg时，催化剂量为150 mg，乙腈量为2 ml，0.5 MPa的氧气，40℃下反应4 h，2,3,5-三甲基-1,4-苯醌的收率可以达到99%。催化剂Cu/PPhen-4具有较好的稳定性，可以回收至少五次，活性几乎没有下降。     

梯度电流密度下电沉积制备铜-镍-钼合金电极及其性能研究

采用梯度电沉积法制备铜基Cu–Ni–Mo合金电极,电流密度参数为:10 mA/cm^2×5 min+30 mA/cm^2×40 min+50 mA/cm^2×5 min。通过扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和X射线光电子能谱仪(XPS)分析了Cu–Ni–Mo合金镀层的表面形貌、元素组成、相结构和各元素的化学价态,并通过线性扫描伏安曲线(LSV)、电化学阻抗谱(EIS)和计时电流法对比了Cu–Ni和Cu–Ni–Mo合金电极在1 mol/L KOH溶液中的析氢性能和稳定性。结果表明,所得Cu–Ni–Mo合金镀层是呈花椰菜多孔形貌的非晶态结构。与Cu–Ni合金电极相比,Cu–Ni–Mo合金电极具有更大的比表面积,可为析氢反应提供更多活性位点,表现出更好的析氢性能,稳定性也更好。     

CuxNi1-xO nanostructures and their nanocomposites with reduced graphene oxide: Synthesis,characterization, and photocatalytic applications

NiO nanostructure was synthesized using a simple co-precipitation method and was embedded on reduced graphene oxide surface via ultrasonication. Structural investigations were made through X-ray diffraction (XRD) and functional groups were confirmed by Fourier transform infrared spectroscopy (FTIR). XRD analysis revealed the grain size reduction with doping. Fourier transform infrared spectroscopy confirmed the presence of metal-oxygen bond in pristine and doped NiO nanostructure as well as the presence of carbon containing groups. Scanning electron microscopy (SEM) indicated that the particle size decreased when NiO nanostructure was doped with copper. BET surface area was found to increase almost up to 43 m²/g for Cu doped NiO nanostructure/rGO composite. Current-voltage measurements were performed using two probe method. UV–Visible spectroscopic profiles showed the blue and red shift for Cu doped NiO nanostructure and Cu doped NiO Nanostructure/rGO composite respectively. Rate constant for Cu doped NiO nanostructure/rGO composite found to increase 4.4 times than pristine NiO nanostructure.