3 resultados para zinc electrolysis
em Bucknell University Digital Commons - Pensilvania - USA
Resumo:
A new concept for a solar thermal electrolytic process was developed for the production of H-2 from water. A metal oxide is reduced to a lower oxidation state in air with concentrated solar energy. The reduced oxide is then used either as an anode or solute for the electrolytic production of H-2 in either an aqueous acid or base solution. The presence of the reduced metal oxide as part of the electrolytic cell decreases the potential required for water electrolysis below the ideal 1.23 V required when H-2 and O-2 evolve at 1 bar and 298 K. During electrolysis, H-2 evolves at the cathode at 1 bar while the reduced metal oxide is returned to its original oxidation state, thus completing the H-2 production cycle. Ideal sunlight-to-hydrogen thermal efficiencies were established for three oxide systems: Fe2O3-Fe3O4, Co3O4-CoO, and Mn2O3-Mn3O4. The ideal efficiencies that include radiation heat loss are as high or higher than corresponding ideal values reported in the solar thermal chemistry literature. An exploratory experimental study for the iron oxide system confirmed that the electrolytic and thermal reduction steps occur in a laboratory scale environment.
Resumo:
The addition of a ZnS shell to CdSe and CdS quantum dot cores was explored using various methods. Spectrophotometry was used to assess the success of ZnS overcoating, which produces both an increase in overall fluorescence and decrease in particle size distribution. A new method was developed, involving preheating of the zinc and sulfide precursor solutions, resulting in CdSe(ZnS) particles with improved fluorescence and a more uniform shell coating from oleylamine-capped CdSe core particles.
Resumo:
In this study zinc compounds containing coordination spheres similar to those in zinc metalloenzymes were identified as targets for potential investigation by ssNMR. The title compounds, zinc catena-(tetrakis(µ2-Benzoato-O,O’))-di-zinc(II), diaquabis(salicylato) zinc, Zn2PSAP(OAc)2, cis-diaqua-diglycolatozinc (II), hexaaquazinc(II)p-hydroxybenzoate dihydrate, and catena-((µ-3-nitrobenzoato) (µ-3-nitrobenzoic acid)sodium) were synthesized, crystallized and their structures solved using single crystal Xray diffraction