Science Daily December 13, 2022
Harvesting an electrical current from biological photosynthetic systems is typically achieved by immersion of the system into an electrolyte solution. Researchers in Israel used the thick water-preserving outer cuticle of the succulent Corpuscularia lehmannii serves as the electrochemical container, the inner water content as the electrolyte into which an iron anode and platinum cathode were introduced. They produced up to 20 μA/cm2 bias-free photocurrent. When 0.5 V bias was added to the iron anode, the current density increased ∼10-fold, and evolved hydrogen gas could be collected with a Faradaic efficiency of 2.1 and 3.5% in dark or light, respectively. The addition of the photosystem II inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea inhibited the photocurrent, indicating that water oxidation was the primary source of electrons in the light, NADH and NADPH served as the major mediating electron transfer molecules, functionally connecting photosynthesis to metal electrodes…read more. TECHNICAL ARTICLE
Graphical abstract. Credit: ACS Appl. Mater. Interfaces 2022, 14, 48, 53761–53766, November 23, 2022