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1.
Chemistry ; 21(42): 14753-7, 2015 Oct 12.
Article in English | MEDLINE | ID: mdl-26306833

ABSTRACT

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 cm(3) g(-1) , respectively), due to the presence of a hierarchical pore system. A high specific surface area of 1671 m(2) g(-1) was achieved, rendering this synthesis route a highly convenient method to produce ordered mesoporous carbons.

2.
Angew Chem Int Ed Engl ; 54(6): 1941-5, 2015 Feb 02.
Article in English | MEDLINE | ID: mdl-25522081

ABSTRACT

There is significant interest in high-performance materials that can directly and efficiently capture water vapor, particularly from air. Herein, we report a class of novel porous carbon cuboids with unusual ultra-hydrophilic properties, over which the synergistic effects between surface heterogeneity and micropore architecture is maximized, leading to the best atmospheric water-capture performance among porous carbons to date, with a water capacity of up to 9.82 mmol g(-1) at P/P0 =0.2 and 25 °C (20% relative humidity or 6000 ppm). Benefiting from properties, such as defined morphology, narrow pore size distribution, and high heterogeneity, this series of functional carbons may serve as model materials for fundamental research on carbon chemistry and the advance of new types of materials for water-vapor capture as well as other applications requiring combined highly hydrophilic surface chemistry, developed hierarchical porosity, and excellent stability.

3.
ACS Nano ; 8(12): 12130-40, 2014 Dec 23.
Article in English | MEDLINE | ID: mdl-25435132

ABSTRACT

Silica nanospheres are used as templates for the generation of carbide-derived carbons with monodisperse spherical mesopores (d=20-40 nm) and microporous walls. The nanocasting approach with a polycarbosilane precursor and subsequent pyrolysis, followed by silica template removal and chlorine treatment, results in carbide-derived carbons DUT-86 (DUT=Dresden University of Technology) with remarkable textural characteristics, monodisperse, spherical mesopores tunable in diameter, and very high pore volumes up to 5.0 cm3 g(-1). Morphology replication allows these nanopores to be arranged in a nanostructured inverse opal-like structure. Specific surface areas are very high (2450 m2 g(-1)) due to the simultaneous presence of micropores. Testing DUT-86 samples as cathode materials in Li-S batteries reveals excellent performance, and tailoring of the pore size allows optimization of cell performance, especially the active center accessibility and sulfur utilization. The outstanding pore volumes allow sulfur loadings of 80 wt %, a value seldom achieved in composite cathodes, and initial capacities of 1165 mAh gsulfur(-1) are reached. After 100 cycle capacities of 860 mAh gsulfur(-1) are retained, rendering DUT-86 a high-performance sulfur host material.

4.
J Colloid Interface Sci ; 411: 187-93, 2013 Dec 01.
Article in English | MEDLINE | ID: mdl-24041548

ABSTRACT

A novel approach for the fabrication of metal coated micro- and nanoparticles by functionalization with a thin polydopamine layer followed by electroless plating is reported. The particles are initially coated with polydopamine via self-polymerization. The resulting polydopamine coated particles have a surface rich in catechols and amino groups, resulting in a high affinity toward metal ions. Thus, they provide an effective platform for selective electroless metal deposition without further activation and sensitization steps. The combination of a polydopamine-based functionalization with electroless plating ensures a simple, scalable, and cost-effective metal coating strategy. Silver-plated tungsten carbide microparticles, copper-plated tungsten carbide microparticles, and copper-plated alumina nanoparticles were successfully fabricated, showing also the high versatility of the method, since the polymerization of dopamine leads to the formation of an adherent polydopamine layer on the surface of particles of any material and size. The metal coated particles produced with this process are particularly well suited for the production of metal matrix composites, since the metal coating increases the wettability of the particles by the metal, promoting their integration within the matrix. Such composite materials are used in a variety of applications including electrical contacts, components for the automotive industries, magnets, and electromagnetic interference shielding.


Subject(s)
Indoles/chemistry , Metals/chemistry , Nanoparticles , Polymers/chemistry , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , X-Ray Diffraction
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