Photocurrent generation based on a light-driven proton pump in an artificial liquid membrane

Xiaojiang Xie, Gaston A. Crespo, Günter Mistlberger, Eric Bakker*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Biological light-driven proton pumps use light to move protons across a cell membrane, creating a proton gradient. Although photochromic compounds such as spiropyrans can reversibly convert between two structures with differing pKa values, spiropyrans have not been used to generate either a light-driven proton pump or an electrical current. Here, we report an artificial light-harvesting system based on a supported liquid membrane doped with a spiropyran. Irradiating the membrane with ultraviolet light induces a ring-opening reaction, converting spiropyran to merocyanine, whereas irradiation with visible light induces the reverse reaction. When the membrane is irradiated with ultraviolet and visible light on opposite sides, H+ is taken up by merocyanine, carried through the polymeric membrane and released on the other side. We show that this system produces a light-induced proton flux, an electrical current with an efficiency of ∼0.12%, an open-circuit voltage of ∼210 mV and a membrane gradient of ∼3.6 ΔpH units. Alternating the sides illuminated with ultraviolet and visible light generates an alternating current
Original languageEnglish
Pages (from-to)202-207
JournalNature Chemistry
Publication statusPublished - 2014

Fields of Expertise

  • Advanced Materials Science

Treatment code (Nähere Zuordnung)

  • Basic - Fundamental (Grundlagenforschung)

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