Electrical, Transport, and Optical Properties of Multifunctional Graphitic Films Synthesized on Dielectric Surfaces by Nickel Nanolayer-Assisted Pyrolysis.

We demonstrate that predepositing a nanometrically thin nickel film on a dielectric surface is sufficient to transform an amorphous pyrolyzed photoresist film (PPF) into a graphitic film (GRF) enriched with nickel particles. The GRF shows 3 orders of magnitude higher carrier mobility than the amorphous PPF, whereas its electrical conductivity doubles after etching away the nickel remains. The pronounced 2D peak in the Raman spectrum, almost dispersionless absorbance in the spectral range of 750-2000 nm, and the saturable absorption coefficient indicate that GRF possesses a graphene-like band structure.

Gold Nanoparticles on 3D-Printed Filters: From Waste to Catalysts.

Three-dimensionally printed solid but highly porous polyamide-12 (PA12) plate-like filters were used as selective adsorbents for capturing tetrachloroaurate from acidic solutions and leachates to prepare PA12-Au composite catalysts. The polyamide-adsorbed tetrachloroaurate can be readily reduced to gold nanoparticles by using sodium borohydride, ascorbic acid, hydrogen peroxide, UV light, or by heating. All reduction methods led to polyamide-anchored nanoparticles with an even size distribution and high dispersion.

Scalable fabrication of the graphitic substrates for graphene-enhanced Raman spectroscopy.

We propose direct synthesis of ultra-thin graphitic films on a dielectric substrate using sacrificial Ni catalyst layer, which significantly increases the crystallinity of the photoresist pyrolyzed at the temperature of 800 °C and above. A considerable amount of multilayer graphene in the photoresist film pyrolyzed in the presence of the Ni catalyst gives rise to an enhancement of the Raman signal of dye Sudan III molecules deposited on the substrate. We demonstrate comparable enhancement of the Raman signal from Sudan III molecules deposited on the fabricated graphitic substrate and those deposited on graphene, which was conventionally transferred to the silica substrate.

Influence of the pore structure of MCM-41 and SBA-15 silica fibers on atomic layer chemical vapor deposition of cobalt carbonyl.

Mesoporous high surface area MCM-41 and SBA-15 type silica materials with fibrous morphology were synthesized and used as support materials for the ALCVD (atomic layer chemical vapor deposition) preparation of Co/MCM-41 and Co/SBA-15 catalysts. Co/MCM-41 and Co/SBA-15 catalysts were prepared by deposition of Co2(CO)8 from the gas phase onto the surfaces of preheated support materials in a fluidized bed reactor. For both silica materials, two different kinds of preparation methods, direct deposition and a pulse deposition method, were used.