Correction: Enhanced photoelectrochemical water oxidation via atomic layer deposition of TiO2 on fluorine-doped tin oxide nanoparticle films.

Correction for 'Enhanced photoelectrochemical water oxidation via atomic layer deposition of TiO2 on fluorine-doped tin oxide nanoparticle films' by Isvar A. Cordova, et al., Nanoscale, 2015, 7, 8584-8592.

Enhanced photoelectrochemical water oxidation via atomic layer deposition of TiO2 on fluorine-doped tin oxide nanoparticle films.

TiO2 is an exemplary semiconductor anode material for photoelectrochemical (PEC) water-splitting electrodes due to its functionality, long-term stability in corrosive environments, nontoxicity, and low cost. In this study, TiO2 photoanodes with enhanced photocurrent density were synthesized by atomic layer deposition (ALD) of TiO2 onto a porous, transparent, and conductive fluorine-doped tin oxide nanoparticle (nanoFTO) scaffold fabricated by solution processing. The simplicity and disordered nature of the nanoFTO nanostructure combined with the ultrathin conformal ALD TiO2 coatings offers advantages including decoupling charge carrier diffusion length from optical penetration depth, increased photon absorption probability through scattering, complimentary photon absorption, and favorable interfaces for charge separation and transfer across the various junctions.

Photoinduced interfacial electron transfer within a mesoporous transparent conducting oxide film.

Interfacial electron transfer to and from conductive Sn-doped In2O3 (ITO) nanoparticles (NPs) in mesoporous thin films has been investigated by transient absorption measurements using surface-bound [Ru(II)(bpy)2(dcb)](2+) (bpy is 2,2'-bipyridyl and dcb is 4,4'-(COOH)2-2,2'-bipyridyl). Metal-to-ligand charge transfer excitation in 0.1 M LiClO4 MeCN results in efficient electron injection into the ITO NPs on the picosecond time scale followed by back electron transfer on the nanosecond time scale.

Water oxidation and oxygen monitoring by cobalt-modified fluorine-doped tin oxide electrodes.

Electrocatalytic water oxidation occurs at fluoride-doped tin oxide (FTO) electrodes that have been surface-modified by addition of Co(II). On the basis of X-ray photoelectron spectroscopy and transmission electron microscopy measurements, the active surface site appears to be a single site or small-molecule assembly bound as Co(II), with no evidence for cobalt oxide film or cluster formation. On the basis of cyclic voltammetry measurements, surface-bound Co(II) undergoes a pH-dependent 1e(-)/1H(+) oxidation to Co(III), which is followed by pH-dependent catalytic water oxidation.

Solution-processed, antimony-doped tin oxide colloid films enable high-performance TiO2 photoanodes for water splitting.

Photoelectrochemical (PEC) water splitting and solar fuels hold great promise for harvesting solar energy. TiO2-based photoelectrodes for water splitting have been intensively investigated since 1972. However, solar-to-fuel conversion efficiencies of TiO2 photoelectrodes are still far lower than theoretical values.

Splitting CO2 into CO and O2 by a single catalyst.

The metal complex [(tpy)(Mebim-py)Ru(II)(S)](2+) (tpy = 2,2' : 6',2''-terpyridine; Mebim-py = 3-methyl-1-pyridylbenzimidazol-2-ylidene; S = solvent) is a robust, reactive electrocatalyst toward both water oxidation to oxygen and carbon dioxide reduction to carbon monoxide. Here we describe its use as a single electrocatalyst for CO(2) splitting, CO(2) → CO + 1/2 O(2), in a two-compartment electrochemical cell.

Interfacial electron transfer dynamics following laser flash photolysis of [Ru(bpy)2((4,4'-PO3H2)2bpy)]2+ in TiO2 nanoparticle films in aqueous environments.

Nanosecond laser flash photolysis has been used to investigate injection and back electron transfer from the complex [(Ru(bpy)(2)(4,4'-(PO(3)H(2))(2)bpy)](2+) surface-bound to TiO(2) (TiO(2)-Ru(II)). The measurements were conducted under conditions appropriate for water oxidation catalysis by known single-site water oxidation catalysts. Systematic variations in average lifetimes for back electron transfer, <τ(bet)>, were observed with changes in pH, surface coverage, incident excitation intensity, and applied bias.

Application of high surface area tin-doped indium oxide nanoparticle films as transparent conducting electrodes.

Metal complex derivatized, optically transparent nanoparticle films of Sn(IV)-doped In(2)O(3) (nanoITO) undergo facile interfacial electron transfer allowing for rapid, potential controlled color changes, direct spectral (rather than current) monitoring of voltammograms, and multilayer catalysis of water oxidation.

Using the voids. Evidence for an antenna effect in dye-sensitized mesoporous TiO2 thin films.

Composite structures of Ru(bpy)(2)(4,4'-(PO(3)H(2))(2)bpy)(2+) surface bound to nanocrystalline TiO(2) with an overlayer of Ru(bpy)(3)(2+) ion exchanged into Nafion, FTO|nanoTiO(2)-[Ru(bpy)(2)(4,4'-(PO(3)H(2))(2)bpy)](2+)/Nafion,Ru(bpy)(3)(2+) (FTO = fluorine-doped tin oxide), have been prepared and characterized. Steady-state emission and time-resolved lifetime measurements demonstrate that energy transfer occurs from Nafion,Ru(bpy)(3)(2+*) to adsorbed Ru(bpy)(2)(4,4'-(PO(3)H(2))(2)bpy)(2+) with an efficiency of ∼0.49.

Catalytic water oxidation on derivatized nanoITO.

Electrocatalytic water oxidation occurs on high surface area, nanocrystalline ITO (nanoITO) surface-derivatized by phosphonate-binding of the catalyst [Ru(Mebimpy)(4,4'-((HO)(2)OPCH(2))(2)bpy)(OH(2))](2+) (Mebimpy is 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy is 2,2'-bipyridine). With nanoITO, spectral data can be acquired on electrochemically generated intermediates and voltammograms monitored spectrophotometrically.

Concerted O atom-proton transfer in the O-O bond forming step in water oxidation.

As the terminal step in photosystem II, and a potential half-reaction for artificial photosynthesis, water oxidation (2H(2)O --> O(2) + 4e(-) + 4H(+)) is key, but it imposes a significant mechanistic challenge with requirements for both 4e(-)/4H(+) loss and O-O bond formation. Significant progress in water oxidation catalysis has been achieved recently by use of single-site Ru metal complex catalysts such as [Ru(Mebimpy)(bpy)(OH(2))](2+) [Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy = 2,2'-bipyridine]. When oxidized from to Ru(V) = O(3+), these complexes undergo O-O bond formation by O-atom attack on a H(2)O molecule, which is often the rate-limiting step.

Making oxygen with ruthenium complexes.

Mastering the production of solar fuels by artificial photosynthesis would be a considerable feat, either by water splitting into hydrogen and oxygen or reduction of CO(2) to methanol or hydrocarbons: 2H(2)O + 4hnu --> O(2) + 2H(2); 2H(2)O + CO(2) + 8hnu --> 2O(2) + CH(4). It is notable that water oxidation to dioxygen is a key half-reaction in both. In principle, these solar fuel reactions can be coupled to light absorption in molecular assemblies, nanostructured arrays, or photoelectrochemical cells (PECs) by a modular approach.

Photoassisted overall water splitting in a visible light-absorbing dye-sensitized photoelectrochemical cell.

Iridium oxide nanoparticles stabilized by a heteroleptic ruthenium tris(bipyridyl) dye were used as sensitizers in photoelectrochemical cells consisting of a nanocrystalline anatase anode and a Pt cathode. The dye coordinated the IrO(2) x nH(2)O nanoparticles through a malonate group and the porous TiO(2) electrode through phosphonate groups. Under visible illumination (lambda > 410 nm) in pH 5.

Coupling of titania inverse opals to nanocrystalline titania layers in dye-sensitized solar cells.

We report a quantitative comparison of the photoaction spectra, short circuit current densities, and power conversion efficiencies of dye-sensitized solar cells (DSSCs) that contain bilayers of nanocrystalline TiO2 (nc-TiO2) and titania inverse opal photonic crystals (PCs). Cells were fabricated with PC/nc-TiO2 and nc-TiO2/PC bilayer films on glass/tin oxide anode of the cell, as well as in a split configuration in which the nc-TiO2 and PC layers were deposited on the anode and cathode sides of the cell, respectively. Incident photon current efficiencies at single wavelengths and current-voltage curves in white light were obtained with both cathode and anode side illumination.

Comprehensive investigation of self-assembled monolayer formation on ferromagnetic thin film surfaces.

We report a simple, universal method for forming high surface coverage SAMs on ferromagnetic thin (< or =100 nm) films of Ni, Co, and Fe. Unlike previous reports, our technique is broadly applicable to different types of SAMs and surface types. Our data constitutes the first comprehensive examination of SAM formation on three different ferromagnetic surface types using two different surface-binding chemistries (thiol and isocyanide) under three different preparation conditions: (1) SAM formation on electroreduced films using a newly developed electroreduction approach, (2) SAM formation on freshly evaporated surfaces in the glovebox, and (3) SAM formation on films exposed to atmospheric conditions beforehand.

Bidentate dicarboxylate capping groups and photosensitizers control the size of IrO2 nanoparticle catalysts for water oxidation.

Dicarboxylic acid ligands (malonate, succinate, and butylmalonate) stabilize 2 nm diameter IrO2 particles synthesized by hydrolysis of aqueous IrCl(6)2- solutions. Analogous monodentate (acetate) and tridentate (citrate) carboxylate ligands, as well as phosphonate and diphosphonate ligands, are less effective as stabilizers and lead to different degrees of nanoparticle aggregation, as evidenced by transmission electron microscopy. Succinate-stabilized 2 nm IrO2 particles are good catalysts for water photo-oxidation in persulfate/sensitizer solutions.

Toward exceeding the Shockley-Queisser limit: photoinduced interfacial charge transfer processes that store energy in excess of the equilibrated excited state.

Nanocrystalline (anatase), mesoporous TiO2 thin films were functionalized with [Ru(bpy)2(deebq)](PF6)2, [Ru(bq)2(deeb)](PF6)2, [Ru(deebq)2(bpy)](PF6)2, [Ru(bpy)(deebq)(NCS)2], or [Os(bpy)2(deebq)](PF6)2, where bpy is 2,2'-bipyridine, bq is 2,2'-biquinoline, and deeb and deebq are 4,4'-diethylester derivatives. These compounds bind to the nanocrystalline TiO2 films in their carboxylate forms with limiting surface coverages of 8 (+/- 2) x 10(-8) mol/cm2. Electrochemical measurements show that the first reduction of these compounds (-0.

Light-to-chemical energy conversion in lamellar solids and thin films.

Photocatalytic water splitting by visible light is one of the most difficult and persistent challenges in chemistry. This Forum Article reviews progress in this field, focusing on efforts made in our laboratory to control electron- and energy-transfer reactions, and catalytic hydrogen and oxygen evolution, in lamellar solids and thin films.

Efficient photodissociation of O2 from synthetic heme and heme/M (M = Fe, Cu) complexes.

Single wavelength excitation (lambdaex = 355 or 532 nm) of low-temperature stabilized (198 K) synthetic heme-dioxygen and heme-dioxygen/M complexes, where M = copper or iron in a non-heme environment, results in the dissociation of dioxygen as indicated by the generation of the ferrous heme (Soret band, 427 nm) and the bleaching of the ferric-superoxide (FeIII(O2-)) 410-nm Soret band in the transient absorption difference spectrum. Dioxygen rebinds to the four heme complexes studied with comparable rate constants ( approximately 6-9 x 105 M-1 s-1). However, the quantum yield for complete dissociation of O2 from our simplest heme-O2 complex (F8)FeIII(O2-) (phi = 0.

Photochemical organic oxidations and dechlorinations with a mu-oxo bridged heme/non-heme diiron complex.

Steady state and laser flash photolysis studies of the heme/non-heme mu-oxo diiron complex [((6)L)Fe(III)-O-Fe(III)-Cl](+) (1) have been undertaken. The anaerobic photolysis of benzene solutions of 1 did not result in the buildup of any photoproduct. However, the addition of excess triphenylphosphine resulted in the quantitative photoreduction of 1 to [((6)L)Fe(II).

Ligand-localized electron trapping at sensitized semiconductor interfaces.

Nanocrystalline (anatase), mesoporous TiO2 thin films were derivatized with [Ru(bpy)2(deebq)](PF6)2 or [Os(bpy)2(deebq)](PF6)2, where bpy is 2,2'-bipyridine and deebq is 4,4'-diethylester-2,2'-biquinoline. Both compounds bind to the nanocrystalline TiO2 films with typical limiting surface coverages of 7 (+/-2) x 10-8 mol/cm2. Electrochemical measurements show that the first reduction of these compounds (-0.

Long-range electron transfer across molecule-nanocrystalline semiconductor interfaces using tripodal sensitizers.

Four tripodal sensitizers, Ru(bpy)(2)(Ad-tripod-phen)(2+) (1), Ru(bpy)(2)(Ad-tripod-bpy)(2+) (2), Ru(bpy)(2)(C-tripod-phen)(2+) (3), and Ru(bpy)(2)(C-tripod-bpy)(2+) (4) (where bpy is 2,2'-bipyridine, phen is 1,10-phenanthroline, and Ad-tripod-bpy (phen) and C-tripod-bpy (phen) are tripod-shaped bpy (phen) ligands based on 1,3,5,7-tetraphenyladamantane and tetraphenylmethane, respectively), have been synthesized and characterized. The tripodal sensitizers consist of a rigid-rod arm linked to a Ru(II)-polypyridine complex at one end and three COOR groups on the other end that bind to metal oxide nanoparticle surfaces. The excited-state and redox properties of solvated and surface-bound 1-4 have been studied at room temperature.