不同活化剂对石油焦基活性炭孔结构的影响

以石油焦为原料 ,Na OH,KOH和 Na2 CO3 为活化剂制备活性炭 ,采用氮气吸附考察了不同活化剂对活性炭的比表面积、中孔和微孔孔径分布、孔容积及平均孔径等孔结构的影响 .结果表明 :KOH活化制备的活性炭包含 1 nm的微孔和 4nm的中孔 ,总孔容 0 .648cm3 /g,比表面积大 ;Na OH制备的活性炭以 1 nm的微孔为主 ,占总孔容 ( 0 .1 65 cm3 /g)的 98% ,平均孔径 1 .83nm;Na2 CO3 制备的活性炭以 4nm的中孔为主 ,占总孔容 ( 0 .1 43cm3 /g)的 68.5 % ,平均孔径 3.42 nm,比表面积小 .3种样品的孔径都呈现出多峰分布特征 .KOH和 Na2 CO3 活化制备的活性炭的 N2 吸附脱附曲线属于 型 ,Na OH活化制备的活性炭吸附脱附曲线属于 型 .     

碳纳米管及C60和石墨氧化动力学机理函数的分析

The oxidation of carbon nanotubes, C60 and graphite was studied by thermogravimetric (TG) analysis and differential thermal analysis (DTA) technique, and the oxidation kinetic models of three carbon materials studied were analyzed by mechanism-function method. The results indicate that three carbon species adopt different oxidation mechanisms due to their different structures. The oxidation of carbon nanotubes with cylindrical structure follows contracting volume reaction mechanism [R3 mechanism, 1-(1-α)1/3 = kt], indicating that the oxidation of carbon nanotubes takes place from the ends to the center. For graphite with planar sandwich structure, the oxidation starts at the edges initially and gradually moves toward the center, which corresponds to contracting area phase boundary reaction mechanism [R2 mechanism, 1-(1-α)1/2 = kt]. The oxidation of C60 with spherical structure, however, is complex and apparently cannot be illustrated with a single kinetic model. The values of apparent activation energy     

The dynamic adsorption of benzene vapor on the ACF activated by phosphoric acid

The dynamic adsorption behaviors of benzene vapor on phosphoric acid‐activated carbon fiber (ACF‐P) were investigated by gas chromatography. The experimental results showed that ACF‐P that was activated at >350^°C, like steam‐activated carbon fiber (ACF‐W), has good dynamic adsorption properties for benzene vapor. However, the saturation adsorption capacities of ACF‐P and ACF‐W are different. The dynamic adsorption conditions apparently do not affect the effluent concentration before the breakthrough point, but do change the operation loading and usage efficiency. The adsorbed ACF‐P can be regenerated, and good dynamic adsorbability can be recovered by heating treatment. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1841–1847, 2002     

光催化剂SrTiO3的制备及其性能的研究

论述用化学液相共沉淀法制备SrTiO_3的最佳条件,及在不同的活化条件下对SrTiO_3光催化性能的影响。此外还研究了掺入过渡金属氧化物对SrTiO_3催化性能的改善。     

Carbon nanofibers: Synthesis, characterization, and electrochemical properties

Carbon nanofibers (CNFs) have been synthesized by co-catalyst deoxidization process by a reaction between C₂H₅OC₂H₅, Zn and Fe powder at 650 °C for 10 h. These nanofibers exhibit diameters of ∼80 nm and lengths ranging from several micrometers to tens of micrometers. X-ray diffraction, Raman spectroscopy, and high-resolution transmission electron microscopy indicate that as-prepared CNFs possess low graphitic crystallinity. The resultant CNFs as electrode shows capacity of ∼220 mAh/g and high reversibility with little hysteresis in the insertion/deintercalation reactions of lithium-ion. In addition, the possible growth of CNFs is discussed.     

中药降香对酪氨酸酶激活作用的动力学研究

酪氨酸酶是生物合成黑素的主要酶。降香有促进酪氨酸酶活性的作用。通过对中药降香的水提取液和乙醇提取液促进酪氨酸酶活性作用的观察研究及降香提高酪氨酸酶活性的动力学观察研究，得到Lineweaver-Burk曲线、动力学回归方程及米氏常数Km值。为研究中药有效成分激活黑素细胞的机理奠定了基础。     

煤矸石热活化及相变分析

系统研究了不同温度下热处理活化煤矸石的物相组成和活性组分溶出的变化规律.用差热分析、X射线衍射、红外光谱、核磁共振、电感耦合等离子原子发射光谱和扫描电镜等仪器测试分析煤矸石原矿和不同煅烧温度制备的样品的矿物组成、分子结构、29Si和27Al化学位移、活性Si4 和Al3 溶出量及微观结构.结果表明:煤矸石的活化程度随不同温度下矿物相组成及铝配位情况的变化而改变.连续性的相转变与活性硅、铝的溶出量相对应.     

Electrochemical pre-treatment of effluents containing chlorinated compounds using an adsorbent

Electrochemical pre-treatment of industrial wastewater to remove refractory and/or toxic organic components, making them more amenable to biological treatment, is likely to be more cost-effective than using a physical or chemical process for complete organic removal. This paper demonstrates the use of a carbon-based adsorbent material that preferentially removes chlorinated organic compounds. Electrochemical regeneration of the adsorbent is shown to be a quick, easy and cheap process, because the adsorbent is both highly electrically conducting and non-porous. High regeneration rates over a number of cycles were obtained by passing a charge of 25 C g⁻¹ through a bed of adsorbent particles, at a current density of 20 mA cm⁻² for 10 min. The energy required to remove a kg of COD from an industrial wastewater was calculated to be 27 kWh.     

Electrochemical properties of carbon-coated CaWO4 versus Li

Carbon-coated CaWO₄ nano-crystalline phases have been synthesized by ambient temperature solution precipitation method, characterized by X-ray diffraction, SEM and thermogravimetry and their electrochemical properties were studied versus Li metal. Galvanostatic cycling at a current of 60 mA/g in the voltage range 0.005-3.0 V on the 5 wt.% C-coated CaWO₄ gave a reversible capacity of 230 ± 5 mAh/g corresponding to 2.5 mol of Li, which is almost stable from 20 to 50 cycles. Under the same conditions, the 10 wt.% C-coated CaWO₄ showed a capacity of 355 ± 5 mAh/g (3.8 mol of Li) during the initial cycles, but the capacity degraded at a rate of 1.6 mAh/g per cycle in the range 5-100 cycles. A good operating voltage range was found to be 0.005-3.0 V with average discharge and charge potentials being 0.6 and 1.3 V, respectively. Coulombic efficiency in all cases was 96-98%. Cyclic voltammograms compliment the galvanostatic results. Impedance spectral data on the 10 wt.% C-coated CaWO₄ at different voltages during the first and 20th discharge-charge cycle have been interpreted in terms of the variations in the bulk and charge-transfer resistances of the composite electrode. A reaction mechanism involving the formation/decomposition of the oxide bronze, ‘Li_xWO_y’ has been proposed to explain the electrochemical cycling.     

活性炭制作研究进展

活性炭的研究非常活跃。原料的广泛性，工艺的先进性，产品性能的特殊性都受到活性炭使用者的广泛关注，特综述了近年来活性炭研制进展概况并对活性炭的研制作展望。