纳米碳材料非金属催化的研究进展

纳米碳材料直接作为催化剂的非金属碳催化是目前材料科学与催化领域的前沿方向之一.相对于传统金属催化剂,纳米碳材料催化剂具有高效环保、低能耗、耐腐蚀等优点.在烃类转化、化学品合成、能源催化等领域表现出优异的催化性能和发展潜力.综述了近年来纳米碳非金属催化研究的最新进展,主要包括新型纳米碳材料的表面性质、催化特性、反应机理和宏观制备等关键问题,并对纳米碳催化存在的挑战和前景进行了展望.     

Poly‐ε‐Lysine Modified Nanocarbon Film Electrodes for LPS Detection

We developed an electrochemical system for detecting lipopolysaccharide (LPS) that uses an ultraflat nanocarbon film electrode modified with poly‐ε‐lysine with a high affinity to LPS. LPS was captured on the modified electrode, and then ferrocene labeled polymyxin B (FcPMB) was captured on the LPS adsorbed electrode via the LPS‐PMB affinity interaction. The adsorbed FcPMB provided an amplified response with Fe²⁺ ions, and the current response was dependent on the amount of captured LPS (LOD=2.0 ng/mL). This was due to the efficient accumulation of the obtained current for LPS and the very low noise made possible by the ultraflat surface.     

Carbon films grown on Pt(1 1 1) as supports for model gold catalysts

Carbon films were grown on a Pt(1 1 1) single crystal by ethylene decomposition at elevated temperatures (1000-1300 K). Depending on the preparation conditions, different carbon structures formed on the metal surface such as flat and curved graphitic layers, carbon particles and carbon nanowires. Although these carbon films exhibited a high density of surface defects, gold interacted only weakly with the carbon surface. CO adsorption on the Au/carbon systems was very similar to that observed for various Au/oxide systems previously studied. This finding strongly indicates that CO adsorption on gold is essentially independent of the nature of support.     

Structural and electrochemical properties of SnO2/nanocarbon families as lithium-ion battery anodes

Hybrid SnO₂/nanocarbon families (graphene nanosheets (GNSs), single-wall carbon nanotubes (SWCNTs), multi-wall carbon nanotubes (MWCNTs) and carbon nanospheres (CNSs)) have been synthesized by a similar wet chemical method. SnO₂ nanoparticles are uniformly loaded on the surface of the nanocarbon families. As lithium battery anodes, their electrochemical properties of the reaction of lithium are investigated under the same conditions. To compare between them, SnO₂/GNSs have the largest capacity; SnO₂/GNSs and SnO₂/SWCNTs have high cyclability; and SnO₂/MWCNTs can maintain the capacity at high current density. Such behaviors are ascribed to their surface-to-volume ratio, structure flexibility, ion mobility and electron conductivity. The present results are the bases for their practical applications in lithium-ion battery anodes.     

The green synthesis of exceptional braided,helical carbon nanotubes and nanospiral platelets made directly from CO2

Helical carbon nanotubes currently cost ~15,000–19,000 USD/kg commercially and are ~10–15 times the price of straight carbon nanotubes of similar dimensions. They have not previously been made from the greenhouse gas CO₂ nor had new variants of the helical morphology been demonstrated. In this study, a novel, inexpensive electrosynthesis of these helical nanocarbon materials from CO₂ is presented. This material may be produced by molten carbon growth conditions that (1) maximize torsional stresses, such as those that may occur during rapid, nucleated carbon reduction, (2) enhance defects that cause formation of heptagonal, rather than the conventional hexagonal building blocks of graphene cylindrical walls, and (3) uniformly control those enhanced defects to repeatedly induce a uniform spiral conformation. These conditions are achieved with at least two of the following experimental conditions: (i) high electrolysis current density, (ii) sp³ defect-inducing agents, such as added oxide, and (iii) controlled concentration of iron added to the electrolyte or cathode. Here, it is shown with SEM, TEM, EDX, XRF, and Raman spectroscopy that a molten controlled electrolyte carbonate synthesis to induce defect formation, and a high rate of electrolysis (0.6 A/cm²) leads to a high yield of helical nanotubes, helical nanofibers, or helical nanoplatelet carbon morphologies.     

我国C60和碳纳米管的研究进展

自从Ｃ６０富勒烯、碳主管被发现和大量制备以来的十几年,由于其独特的分子结构和化学、物理性质,使它们成为目前研究的热点。在这十几年里,我国在这些方面的研究取得了些重要的研究成果。本文从我国在富勒烯的制备和分离,理论,富勒烯的化学修饰,富勒烯在电、磁、光材料中的应用,富勒烯金属包合物的研究以及碳纳米管的研究等方面进行了回顾。     

The Rules in the Geometric Structure of Tetrahedral (Td) Nanocarbons

The main purpose of this article is to find the rules for the geometric structure of the tetrahedral (T_d) nanocarbons. Also, we would like to demonstrate the ways that we derive the formulas for these rules by simple figures and illustrations. We hope that with these derived formulas of the rules, we will be able to derive all types of the Tetrahedral Nanocarbon Clusters (without consideration for the case of distortion).     

Simultaneous Detection of Homocysteine and Cysteine in the Presence of Ascorbic Acid and Glutathione Using a Nanocarbon Modified Electrode

The simultaneous electrochemical detection of homocysteine and cysteine using an absorbed ortho‐quinone species, catechol, at the nanocarbon modified glassy carbon electrode was achieved via 1,4‐Michael addition reaction. The detection was done in the presence and the absence of each other as well as with both glutathione and ascorbic acid present in order to investigate the selectivity of homocysteine and cysteine. A determination of homocysteine sensitivity is (0.882±0.296) nA nM^?1 with a LOD of ca. 11 nM and cysteine sensitivity is (7.501±0.202) mA µM^?1 with a LOD of ca. 5.0 µM within a range of 0–0.1 mM.     

电催化剂纳米碳基载体的研究进展

质子交换膜燃料电池(PEMFCs)因具有工作温度低、结构紧凑、无腐蚀、启动快和灵活性好等优点,受到人们广泛关注.但其工作时动力学迟缓且易受CO毒化影响,往往需要负载Pt等贵金属催化剂,导致PEMFCs的成本高昂,阻碍了其商业化应用.为提高Pt贵金属的利用率,通常将Pt负载在载体材料上来提高Pt的分散性以减少Pt颗粒集聚...     

利用ＳＢＡ-１５介孔内纳米碳合成含介孔的ＺＳＭ-５分子筛

SBA-15介孔分子筛内填充蔗糖并炭化后, 分别在碱性和弱酸性条件下, 用含铝源及TPABr的溶液浸渍,将SBA-15分子筛孔壁的无定形结构转化成ZSM-5分子筛的晶体结构, 除碳后得到含介孔的ZSM-5分子筛. 用X射线衍射、 N_2吸附-脱附、 ~(27)Al MAS NMR、 NH_3-TPD、 TEM、 SEM等对样品进行了表征, 考察了晶化时间等参数对样品的影响. 结果表明, 碱性条件下合成的ZSM-5分子筛晶体中含有少量孔径约3.2～4.2 nm的介孔孔道, 其酸强度接近与常规ZSM-5分子筛的酸强度;弱酸性条件下合成的ZSM-5分子筛晶体中含有大量孔径约1.4～1.6 nm的孔道, 其酸强度明显低于常规ZSM-5分子筛的酸强度.