Key features of the deep eutectic solvent-microwave assisted simultaneous extraction of polyphenols and delignification pretreatment of chestnut shell waste are presented.
1 September 2011 in Applied Catalysis B: Environment and Energy
The crystal structure of GaP nanowires grown by Au-assisted chemical beam epitaxy was investigated as a function of group V flux and growth temperature. By increasing the tertiarybutyl phosphine flux we obtained nanowires with a stacking defect-free wurtzite crystal structure. Variation of growth temperature also had a profound impact on the crystal structure. Lowering the growth temperature from 600 to 560 °C and keeping constant both triethylgallium and tertiarybutyl phosphine precursor fluxes, the crystal structure of GaP NWs was drastically improved from a highly defective intergrowth of zinc-blende and wurtzite to a wurtzite crystal structure free of stacking defects. These results are compared to current literature on GaP NW growth, and we suggest that the low V/III ratio is the key ingredient for the high crystal quality of our GaP nanowires.
Resonance Raman measurements are carried out on defect-free wurtzite GaP nanowires over the excitation energy range between 2.19 and 2.71 eV. Resonances of the E1(LO) and A1(LO) modes demonstrate the existence of energy states with Γ9hh and Γ7V (Γ7C) symmetries of the valence (conduction) band and enable us to measure wurtzite phase GaP band energies. In addition, we have performed temperature dependent resonant Raman measurements, which allowed us to extrapolate the zero temperature values of Γ point energies. Our results provide the necessary feedback required for refining the available theoretical calculations to derive the correct wurtzite III-V semiconductor band structure.
A chiral ionic liquid with a natural alcohol based chain was used as a tailoring agent for the synthesis of simple and cost effective materials such as ZnO, CuO, CuO–ZnO with peculiar morphology.