Category: Publications

Energy transfer was explored in a series of poly(phenylene ethynylene) (PPE) polymers with increasing lengths that were end-capped with thiophene-benzothiadiazole (TBT) groups to form fully conjugated donor–acceptor polymers. For the polymers in solution, ultrafast transient absorption and time-resolved fluorescence spectroscopy … Read more

Two osmium(II) photocatalysts bearing a dicationic 4,4′-bis-(trimethylaminomethyl)-2,2′-bipyridine (tmam) ligand and 2,2′-bipyridine {[Os(bpy)2(tmam)]4+} or 4,4′-(CF3)2-2,2′-bipyridine {[Os((CF3)2bpy)2(tmam)]4+} ancillary ligands were synthesized and characterized for application in HX splitting. Iodide titration studies in acetone solutions provided evidence for an in situ formed terionic complex with two iodide … Read more

Classical capacitance studies have revealed that the first layer of water present at an aqueous metal-electrolyte interface has a die-lectric constant less than 1/10th that of bulk water. Modern theory indicates that under such solvent conditions the barrier for elec-tron … Read more

The presence of narrow, degenerately-doped axial silicon nanowire (SiNW) p–n junctions via off-axis electron holography (EH) has been confirmed. SiNWs were grown via the vapor-solid-liquid (VLS) mechanism using gold (Au) as the catalyst, silane (SiH4 ), diborane (B2H6 ) and phosphine (PH3 ) as the … Read more

Maximizing the efficiency of solar energy conversion using dye assemblies rests on understanding where the energy goes following absorption. Transient spectroscopies in solution are useful for this purpose, and the time-resolved data are usually analyzed with a sum of exponentials. … Read more

Comparative kinetic studies of a series of new ruthenium complexes provide a platform for understanding how strong trans effect ligands and redox-active ligands work together to enable rapid electrochemical CO2 reduction at moderate overpotential. After synthesizing isomeric pairs of ruthenium … Read more

The performance of dye sensitized solar cells (DSSCs) depends on the properties and interactions of three fundamental components: the semiconductor, chromophore, and electrolyte. For the electrolyte, the dependence of DSSC performance on the identity and valence state of the spectator … Read more

The synthesis, characterization, electrochemical and photophysical properties of the phosphonate-derivatized Carbazole (CBZ) and boron dipyrromethene (BODIPY) chromophores in the dyes, BODIPY(CBZ)2PO3H2 [8] and BODIPY(Tol)2PO3H2 [7], are described. The oxide-bound dyes have been explored as light absorbers in dye-sensitized photoelectrosynthesis cell … Read more

The total reorganization energy, λ, for interfacial electron transfer, ET, from a conductive electrode to redox-active molecules at fixed positions within the electric double layer, EDL, has been determined experimentally. Conductive indium–tin-oxide (ITO, In2O3:Sn) mesoporous films were functionalized with 4-[N,N-di(p-tolyl)-amino]benzylphosphonic … Read more

A new approach is described for the preparation of water oxidation photoanodes in a Dye-Sensitized Photoelectrosynthesis Cell (DSPEC) for water splitting. It is based on a chromophore (C) – catalyst (Cat) assembly prepared by a self-assembled bilayer (SAB) on a … Read more

Molecular excited states at conductive and semiconductive interfaces were found to transfer an electron to the oxide (injection) or accept an electron from the oxide (hole transfer). The direction of this electron transfer was determined by the metal oxide electronic … Read more

In the development of photoelectrochemical cells for water splitting or CO2 reduction, a major challenge is O2 evolution at photoelectrodes that, in behavior, mimic photosystem II. At an appropriate semiconductor electrode, a water oxidation catalyst must be integrated with a visible … Read more

A study of SnO2/TiO2 core/shell films was undertaken to investigate the influence of shell thickness and post deposition sintering on electron localization and transport properties. Electrochemical reduction of the materials resulted in the appearance of a broad visible –near IR … Read more

The atomic layer deposition of tetrakisdimethylamidotin(IV) and water on mesoporous thin films of nanocrystalline anatase TiO2, rutile SnO2, and rutile TiO2 was investigated. For all deposition conditions tested, highly oxygen deficient coatings were created, and purge time and temperature were … Read more

The reorganization energy, λ, for interfacial electron transfer (ET) and for proton-coupled electron transfer (PCET) between a water oxidation catalyst and a conductive In2O3:Sn (ITO) oxide were extracted from kinetic data by application of Marcus–Gerischer theory. Specifically, light excitation of … Read more