Solarchemische Spaltung von Wasser in Wasserstoff und Sauerstoff

• Research unit: SFOE
• Project number: 101783

Key words (German)

TP0066;F - Wasserstoff

Short description (German)

Für die photoelektrochemische Spaltung von Wasser in H2 und O2 wird spektral sensibilisiertes Silberchlorid als Photoanode mit einer Solarzelle aus amorphem Silizium kombiniert. Der Einfluss neuer Herstellungsverfahren auf die Effizienz der AgCl Photoanode wird untersucht (Verwendung von Zeolith A und L Schichten, mesoporöse Materialien oder Membranen als Matrix).

Publications / Results (German)

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Publications / Results (English)

Thin silver chloride layers evolve oxygen under UV/Vis illumination in aqueous solution under appropriate conditions. AgCl deposited on a conducting support photocatalyzes the oxidation of water to O2 in the presence of a small excess of silver ions in solution. The light sensitivity in the visible part of the spectrum is due to self-sensitization caused by the formation of silver species during the photoreaction. Anodic polarization reoxidizes the reduced silver species. Experiments were carried out with gold colloids sedimented on AgCl layers. We observed that small traces of Au colloids greatly influenced the photoelectrochemical activity. AgCl photoanodes as well as gold colloid modified AgCl photoanodes were combined with an amorphous silicon solar cell in a setup for photoelectrochemical water splitting. Illumination of the AgCl photoanode and the amorphous Si solar cell led to photoelectrochemical water splitting into O2 and H2. For AgCl photoanodes modified with gold colloids an increased photocurrent, and consequently a higher O2 and H2 production were observed. AgCl photoanodes were also modified with spherical and prismatic silver nanoparticles. Water oxidation experiments also showed an increased O2 production and photocurrent, though not as high as with gold colloid modification. To increase the active surface area of the AgCl photoanode new synthesis procedures are being developed. Microporous materials as support for the AgCl layer (zeolite A and zeolite L), as well as mesoporous materials as matrix (TiO2 nanotubes, mesoporous WO3, and Al2O3 membranes) are being used.

Auftragnehmer/Contractant/Contraente/Contractor:


Autorschaft/Auteurs/Autori/Authors:
Currao,Antonio