Control of electrons' spin eliminates hydrogen peroxide formation during water splitting

Journal article

The production of hydrogen through water splitting in a photoelectrochemical cell suffers from an overpotential that limits the efficiencies. In addition, hydrogen-peroxide formation is identified as a competing process affecting the oxidative stability of photoelectrodes. We impose spin-selectivity by coating the anode with chiral organic semiconductors from helically aggregated dyes as sensitizers; Zn-porphyrins and triarylamines. Hydrogen peroxide formation is dramatically suppressed, while the overall current through the cell, correlating with the water splitting process, is enhanced. Evidence for a strong spin-selection in the chiral semiconductors is presented by magnetic conducting (mc-)AFM measurements, in which chiral and achiral Zn-porphyrins are compared. These findings contribute to our understanding of the underlying mechanism of spin selectivity in multiple electron-transfer reactions and pave the way toward better chiral dye-sensitized photoelectrochemical cells.

Authors: Mtangi, W; Tassinari, F; Vankayala, K; Vargas Jentzsch, A; Adelizzi, B

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Journal of the American Chemical Society
• Volume: 139
• Issue: 7
• Pages: 2794-2798
• Publication date: 2017-01-30
• Acceptance date: 2017-01-30
• DOI: 10.1021/jacs.6b12971
• ISSN: 0002-7863 and 1520-5126
• Pmid: 28132505
• Language: English
• Keywords: Journal Article; research-article