Atomic structure of cobalt-oxide nanoparticles activein light-driven catalysis of water oxidation

• The atomic structure of water-oxidizing nanoparticles (10-60 nm) formed from cobalt(II)salts and methylenediphosphonate (M2P) is investigated. These amorphous nanoparticles are of high interest for production of solar fuels. They facilitate water oxidation in a directly light-driven process using [Ru(bpy)3]2+ (bpy = 2,2’-bipyridine) as a photosensitizer and persulfate (S2O82-) as an electron acceptor. By X-ray absorption spectroscopy (XAS) at the cobalt K-edge, cobalt L-edge and oxygen K-edge, we investigate the light-driven transition from the CoII/M2P precursor to the active catalyst, which is a layered cobalt(III) oxide with structural similarities to water-oxidizing electrocatalysts. The M2P ligand likely binds at the periphery of the nanoparticles, preventing their further agglomeration during the catalytic reaction. This system opens a possibility to link the catalytically active nanoparticles via a covalent bridge to a photosensitizer and build an artificial photosynthetic system for direct utilization of solar energy for fuel production without production of electricity as an intermediate step.

Subject headings

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

Keyword

Artificial photosynthesis

Photocatalysis

Solar fuels

Water oxidation

X-ray absorption spectroscopy

Artificiell fotosyntes

Fotokatalys

Solbränslen

Vattenoxidation

Röntgenabsorptionsspektroskopi

Publication and Content Type

ref (subject category)

art (subject category)