Control of Electrons' Spin Eliminates Hydrogen Peroxide Formation During Water Splitting.
Wilbert MtangiFrancesco TassinariKiran VankayalaAndreas Vargas JentzschBeatrice AdelizziAnja R A PalmansClaudio FontanesiE W MeijerRon NaamanPublished in: Journal of the American Chemical Society (2017)
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.
Keyphrases
- hydrogen peroxide
- room temperature
- nitric oxide
- density functional theory
- ionic liquid
- capillary electrophoresis
- single molecule
- single cell
- electron transfer
- cell therapy
- induced apoptosis
- transition metal
- heavy metals
- visible light
- sensitive detection
- molecular dynamics
- cell cycle arrest
- mesenchymal stem cells
- cell proliferation
- oxidative stress
- endoplasmic reticulum stress
- aqueous solution
- structural basis
- risk assessment
- high speed
- bone marrow
- molecularly imprinted