Plasmon enhanced light driven water oxidation by a dye sensitized photoanode
Significance Dye sensitized photoelectrosynthesis cells (DSPECs) provide a basis for artificial photosynthesis and solar fuels production. By combining molecular chromophores and catalysts with high surface area, transparent semiconductor electrodes, a DSPEC provides the basis for light driven conversion of water to O2 and H2 or for reduction of CO2 to carbon based fuels. The incorporation of plasmonic cubic silver nanoparticles, with a strongly localized surface plasmon absorbance near 450 nm, to a DSPEC photoanode induces a great increase in the efficiency of water oxidation to O2 at a DSPEC photoanode. The improvement in performance by the molecular components in the photoanode highlights a remarkable advantage for the plasmonic effect in driving the 4e /4H+ oxidation of water to O2 in the photoanode. Dye sensitized photoelectrosynthesis cells (DSPECs) provide a flexible approach for solar water splitting based on the integration of molecular light absorption and catalysis on oxide electrodes. Recent advances in this area, including the use of core/shell oxide interfacial structures and surface stabilization by atomic layer deposition, have led to improved charge separation lifetimes and the ability to obtain substantially improved photocurrent densities. Here, we investigate the introduction of Ag nanoparticles into the core/shell structure and report that they greatly enhance light driven water oxidation at a DSPEC photoanode. Under 1 sun illumination, Ag nanoparticle electrodes achieved high photocurrent densities, surpassing 2 mA cm 2 with an incident photon to current efficiency of 31.8% under 450 nm illumination.
Proceedings of the National Academy of Sciences