Photo-assisted electrodeposition of cobalt–phosphate (Co–Pi) catalyst on hematite photoanodes for solar water oxidation

✍ Scribed by Zhong, Diane K.; Cornuz, Maurin; Sivula, Kevin; Grätzel, Michael; Gamelin, Daniel R.

• Book ID: 111677908
• Publisher: Royal Society of Chemistry
• Year: 2011
• Tongue: English
• Weight: 502 KB
• Volume: 4
• Category: Article
• ISSN: 1754-5692
• DOI: 10.1039/c1ee01034d

✦ Synopsis

A photo-assisted electrodeposition approach was used to deposit a cobalt-phosphate water oxidation catalyst (''Co-Pi'') onto recently improved dendritic mesostructures of a-Fe 2 O 3 . A comparison between this approach, electrodeposition of Co-Pi, and Co 2+ wet impregnation showed that photo-assisted electrodeposition of Co-Pi yields superior a-Fe 2 O 3 photoanodes for photoelectrochemical water oxidation. Stable photocurrent densities of 1.0 mA cm À2 at 1.0 V and 2.8 mA cm À2 at 1.23 V vs. RHE measured under standard illumination and basic conditions were achieved. By allowing deposition only where visible light generates oxidizing equivalents, photo-assisted electrodeposition provides a more uniform distribution of Co-Pi onto a-Fe 2 O 3 than obtained by electrodeposition. This approach of fabricating catalyst-modified metal-oxide photoelectrodes may be attractive for optimization in conjunction with tandem or hybrid photoelectrochemical cells.