Document Detail

Atomistic Structure of Cobalt-Phosphate Nanoparticles for Catalytic Water Oxidation.
MedLine Citation:
PMID:  23145574     Owner:  NLM     Status:  Publisher    
Solar-driven water splitting is a key photochemical reaction that underpins the feasible and sustainable production of solar fuels. An amorphous cobalt-phosphate catalyst (Co-Pi) based on earth-abundant elements has been recently reported to efficiently promote water oxidation to protons and dioxygen, a main bottleneck for the overall process. The structure of this material remains largely unknown. We here exploit ab initio and classical atomistic simulations combined with metadynamics to build a realistic and statistically meaningful model of Co-Pi nanoparticles. We demonstrate the emergence and stability of molecular-size ordered crystallites in nanoparticles initially formed by a disordered Co-O network and phosphate groups. The stable crystallites consist of bis-oxo bridged Co centers that assemble into layered structures (edge-sharing CoO6 octahedra) as well as in corner- and face-sharing cubane units. These layered and cubane motifs coexist in the crystallites, which always incorporate disordered phosphate groups at the edges. Our computational nanoparticles, although limited in size to ~1nm, can contain more than one crystallite and incorporate up to 18 Co centers in the cubane/layered structures. The crystallites are structurally stable up to high temperatures. We simulate the extended X-ray absorption fine structure (EXAFS) of our nanoparticles. Those containing several complete and incomplete cubane motifs - which are believed to be essential for the catalytic activity - display a very good agreement with the experimental EXAFS spectra of Co-Pi grains. We propose that the crystallites in our nanoparticles are reliable structural models of the Co-Pi catalyst surface. They will be useful to reveal the origin of the catalytic efficiency of these novel water-oxidation catalysts.
Xiao Liang Hu; Simone Piccinin; Alessandro Laio; Stefano Fabris
Related Documents :
23106264 - Divalent-anion salt effects in polyelectrolyte multilayer depositions.
24566664 - Liquid filament instability due to stretch-induced phase separation in polymer solution...
24032824 - Low-velocity impact cratering experiments in a wet sand target.
23015694 - In vitro assembly of an empty picornavirus capsid follows a dodecahedral path.
23089594 - Surface-active copolymer formation stabilizes peg droplets and bubbles in silicone foams.
20545884 - Mechanisms independent of abscisic acid (aba) or proline feedback have a predominant ro...
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-11-12
Journal Detail:
Title:  ACS nano     Volume:  -     ISSN:  1936-086X     ISO Abbreviation:  ACS Nano     Publication Date:  2012 Nov 
Date Detail:
Created Date:  2012-11-13     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101313589     Medline TA:  ACS Nano     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Hexagonal platelet-like magnetite as a biosignature of thermophilic iron-reducing bacteria and its a...
Next Document:  Sex at the margins: parthenogenesis vs. facultative and obligate sex in a Neotropical ant.