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[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp 2 -bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

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Carbon-based Supercapacitors Produced by Activation of Graphene

Kenji Sumida, David L. Rogow, Jarad A. Mason, Thomas M. McDonald, Eric D. Bloch, Zoey R. Herm, Tae-Hyun Bae, Jeffrey R. Long

Carbon Dioxide Capture in Metal–Organic Frameworks

Carbon properties and their role in supercapacitors

The effect of the tin content and the reduction temperature on the ability of bimetallic platinum-tin catalysts supported on activated carbon cloth (ACC) to retain hydrogen after the reduction treatments has been analysed by temperature-programmed desorption of hydrogen (H2-TPD). A series of Sn/ACC samples with different tin contents has been prepared by impregnation of ACC with a solution of tin (II) oxalate in diluted HNO3 and subsequent heat-treatment at 623 K under flowing helium. Platinum (1 wt.%) was then introduced by impregnation of the Sn/ACC samples with aqueous solutions of H2PtCl6. Catalysts have been characterised by temperature-programmed reduction under diluted hydrogen and X-Ray Photoelectron Spectroscopy (XPS). The extent of hydrogen spillover from the metallic particles to the support has been determined by H2-TPD, the products being analysed by online mass spectrometry. The presence of tin oxide provides anchoring sites for hydrogen atoms spilt-over from platinum, although the ability of the latter to dissociate H2 molecules seems to be influenced by the presence of tin, both in an oxidised state after reduction at low temperature (523 K) and in the metallic state (possibility of alloy formation) after reduction at higher temperatures (623 and 723 K).

Hydrogen spillover in Pt-Sn catalysts supported on activated carbon cloth.

Copper complexes containing inorganic ligands were loaded on a functionalized titania (F-TiO2) to obtain drug delivery systems. The as-received copper complexes and those released from titania were tested as toxic agents on different cancer cell lines. The sol–gel method was used for the synthesis and surface functionalization of the titania, as well as for loading the copper complexes, all in a single step. The resultant Cu/F-TiO2 materials were characterized by several techniques. An “in vitro” releasing test was developed using an aqueous medium. Different concentrations (15.6–1000 µg mL−1) of each copper complex, those loaded on titania (Cu/F-TiO2), functionalized titania, and cis-Pt as a reference material, were incubated on RG2, C6, U373, and B16 cancer cell lines for 24 h. The morphology of functionalized titania and the different Cu/F-TiO2 materials obtained consists of aggregated nanoparticles, which generate mesopores. The amorphous phase (in dominant proportion) and the anatase phase were the structures identified through the X-ray diffraction profiles. These results agree with high-resolution transmission electron microscopy. Theoretical studies indicate that the copper compounds were released by a Fickian diffusion mechanism. It was found that independently of the copper complex and also the cell line used, low concentrations of each copper compound were sufficient to kill almost 100 % of cancer cells. When the cancer cells were treated with increasing concentrations of the Cu/F-TiO2 materials the number of survival cells decreased. Both copper complexes alone as well as those loaded on TiO2 had higher toxic effect than cis-Pt.

Release of copper complexes from a nanostructured sol–gel titania for cancer treatment

Poly(furfuryl alcohol) was introduced into a pore system of MCM-48 silica by the precipitation polycondensation of furfuryl alcohol (FA). The complete filling of the pores without the deposition of significant amounts of polymer on the external surface of MCM-48 was obtained at the FA/MCM-48 mass ratio close to 1.0. The final structure of carbon replica was formed by subsequent carbonization and extraction of SiO2 with HF. The carbonization temperature strongly influenced the surface composition of the formed carbon replicas. The highest catalytic activity in the oxidative dehydrogenation of ethylbenzene was observed for CMK-1 with the highest concentration of phenol and carbonyl groups, recognized as active sites of the studied reaction.

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Oxidative Dehydrogenation of Ethylbenzene Over Poly(furfuryl alcohol)-Derived CMK-1 Carbon Replica

The preparation process and sintering behavior of different binderless polyaromatic mesophase (BPAM) powders, obtained by extraction of a semicoke (product of pyrolysis of a petroleum residue) with...

Francisco Rodríguez-Reinoso

Papers

Hydrogen spillover in Pt-Sn catalysts supported on activated carbon cloth.

Release of copper complexes from a nanostructured sol–gel titania for cancer treatment

Oxidative Dehydrogenation of Ethylbenzene Over Poly(furfuryl alcohol)-Derived CMK-1 Carbon Replica

Production of High-Strength Carbon Artifacts from Petroleum Residues: Influence of the Solvent Used to Prepare Mesophase Powder

Assessing Generic Force Fields to Describe Adsorption on Metal-Organic Frameworks