RESUMO
In this study, polymer solar cells were synthesized by adding Sb2S3 nanocrystals (NCs) to thin blended films with polymer poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) as the p-type material prepared via the spin-coating method. The purpose of this study is to investigate the dependence of polymer solar cells' performance on the concentration of Sb2S3 nanocrystals. The effect of the Sb2S3 nanocrystal concentrations (0.01, 0.02, 0.03, and 0.04 mg/mL) in the polymer's active layer was determined using different characterization techniques. X-ray diffraction (XRD) displayed doped ratio dependences of P3HT crystallite orientations of P3HT crystallites inside a block polymer film. Introducing Sb2S3 NCs increased the light harvesting and regulated the energy levels, improving the electronic parameters. Considerable photoluminescence quenching was observed due to additional excited electron pathways through the Sb2S3 NCs. A UV-visible absorption spectra measurement showed the relationship between the optoelectronic properties and improved surface morphology, and this enhancement was detected by a red shift in the absorption spectrum. The absorber layer's doping concentration played a definitive role in improving the device's performance. Using a 0.04 mg/mL doping concentration, a solar cell device with a glass /ITO/PEDOT:PSS/P3HT-PCBM: Sb2S3:NC/MoO3/Ag structure achieved a maximum power conversion efficiency of 2.72%. These Sb2S3 NCs obtained by solvothermal fabrication blended with a P3HT: PCBM polymer, would pave the way for a more effective design of organic photovoltaic devices.
RESUMO
We report an approach to the development of advanced structural composites based on engineered multiscale carbon nanotube-carbon fiber reinforcement. Electrophoresis was utilized for the selective deposition of multi- and single-walled carbon nanotubes (CNTs) on woven carbon fabric. The CNT-coated carbon fabric panels were subsequently infiltrated with epoxy resin using vacuum-assisted resin transfer molding (VARTM) to fabricate multiscale hybrid composites in which the nanotubes were completely integrated into the fiber bundles and reinforced the matrix-rich regions. The carbon nanotube/carbon fabric/epoxy composites showed approximately 30% enhancement of the interlaminar shear strength as compared to that of carbon fiber/epoxy composites without carbon nanotubes and demonstrate significantly improved out-of-plane electrical conductivity.
RESUMO
The impregnation of active carbon with two-component aqueous solutions of Cu and Co nitrates has been investigated and different deposition degrees of copper and cobalt ions have been established. Adsorption analysis has shown modification of the active carbon texture after impregnation with solutions whose concentration of Cu and Co ions exceeds 3%. A catalyst with a high activity in the reduction of NO with CO at 100 degrees C has been obtained. All samples are found to catalyze the complete reduction of NO to N2. A correlation between the catalytic activity and the Cu:Co ratio in the supported phase has been established. Copyright 1999 Academic Press.
RESUMO
The reduction of NO with CO on Ni-impregnated active carbon catalysts (AC/Ni) has been investigated. High activity toward NO reduction can be achieved on an AC/Ni catalyst obtained by thermal decomposition of the precursor nitrate at 200°C. The role of active carbon in the catalytic reduction of NO with CO at different temperatures has been discussed. At low temperatures (below 200°C), when there is no substantial gasification of the carbon, dissociative adsorption of NO along with N2 evolution and oxygen accumulation on the carbon surface has been observed. The active sites occupied by the oxygen evolved during the NO decomposition are regenerated by the CO reducing agent. At high temperatures the C-O complexes evolved from the carbon surface participate in NO reduction as a second reducing agent. The effect of the oxygen-containing functional groups and the available nitrate groups on catalyst activity has been discussed. Copyright 1997Academic Press
