The behavior of crystalline nanoparticles depends strongly on which facets are exposed. Some more active than others, but it is difficult to selectively isolate particular facets. This study provides fundamental insights into photocatalytic and photoelectrochemical performance three types TiO2 with predominantly exposed {101}, {010}, or {001} facets, where 86–99% the surface area desired facet. Photodegradation methyl orange reveals that {001}-TiO2 has 1.79 3.22 times higher activity {010}...

Water-splitting dye-sensitized photoelectrochemical cells (WS-DSPECs) use a wide bandgap metal oxide semiconductor functionalized with light-absorbing dye and water-oxidation catalyst to harvest light drive water oxidation, respectively. We demonstrate here that the rutile polymorph of TiO2 (r-TiO2) is promising anode material for WS-DSPECs. Recombination between injected electron oxidized sensitizer r-TiO2 an order magnitude slower than anatase (a-TiO2), injection yields approaching 100%....

Thin mesoporous photoconductive layers are critically important for efficient water-spitting solar cells. A detailed understanding of photoconductivity in these materials can be achieved via terahertz transient absorption measurements. Such measurements commonly interpreted using the thin-film approximation. We compare this approximation with a numerical solution transfer function without approximations experimental results tin oxide (SnO2) samples which range thickness from 3.3 to 12.6 µm....

Abstract Inverse opal scaffolds are finding widespread use in tissue engineering and regenerative medicine. Herein, the way which pore sizes related physical properties of poly( D , L ‐lactide‐ co ‐glycolide) inverse affected by fabrication conditions is systematically investigated. It found that window size an scaffold mainly determined annealing temperature rather than duration time, surface largely concentration infiltration solution. Although with larger or facilitate faster migration...

The development of water-splitting dye-sensitized photoelectrochemical cells has gained interest owing to their ability generate renewable fuels from solar energy. In this study, photoanodes were assembled a SnO2 film sensitized with combination high-potential CF3 -substituted porphyrin dye tetrahydropyranyl-protected hydroxamic acid surface-anchoring group and Cp*Ir (Cp*=pentamethylcyclopentadienyl) water-oxidation catalyst containing silatrane anchoring group. dye/catalyst ratios varied...

Time-resolved terahertz (THz) spectroscopy and open-circuit photovoltage measurements were employed to examine the size-dependent charge carrier dynamics of tungsten(VI) oxide (WO3) particles for their use as photoanode in photoelectrochemical cells. Specifically, films commercially available WO3 nanoparticles (NPs) granular (GPs) with diameters 77 ± 34 390 260 nm, respectively, examined air while immersed 0.1 M Na2SO4 electrolyte (pH = 2). Examination frequency-dependent transient...

This study probes a series of linkers and anchoring groups for direct interfacial electron transfer (IET) from high-potential porphyrins into semiconductor surfaces. Eight different linker–anchor combinations CF3-substituted, were designed, synthesized, characterized. Specifically, four anchors was examined (carboxylate, hydroxamate, phosphonate, silatrane), along with two (phenylene benzanilidylene), which differ in terms their electronic conjugation overall length. The electrochemical...

dl-Norvaline is a molecular crystal at room temperature and it undergoes phase transition when cooled below 190 K. This believed to be Martensitic, thus making of particular interest for machines. In this paper we investigate by measuring its terahertz (THz) spectrum over range temperatures. Temperature-dependent THz time-domain spectroscopy (THz-TDS) measurements reveal that the (Tβ→α) The influence nucleation seeds was analyzed determining Tβ→α crystals with varying grain size. Grains 5 μm...

The transient photoconductive properties of tin(IV) oxide (SnO2) mesoporous films have been studied by time-resolved terahertz (THz) spectroscopy. We gain insight into carrier dynamics measuring overall injection and trapping lifetimes using optical pump–THz probe spectroscopy, as well the frequency-dependent complex conductivity at various pump–probe delay times. It is found that method charge generation, either direct above band gap excitation (at 267 nm) or dye-sensitized electron 400...

Lateral charge transport in a redox-active monolayer can be utilized for solar energy harvesting. A model porphyrin system was chosen to study the influence of solvent on lateral hole hopping, which plays crucial role charge-transfer kinetics. We examined water, acetonitrile, and propylene carbonate as solvents. Hole-hopping lifetimes varied by nearly 3 orders magnitude among solvents, ranging from ns water 2800 carbonate, increased nonlinearly function added acetonitrile aqueous mixtures....

Electron-injection dynamics of dye-sensitized photoelectrochemical cells depend on the length linker connecting molecular photosensitizer to metal oxide electron acceptor. However, systematic studies effect chromophore–oxide distance are scarce. Here we present synthesis, characterization, spectroscopy, and computational modeling electron-injection from free-base trimesitylporphyrins with varying lengths into tin(IV) (SnO2). In each system, porphyrin core film remain same while only binding...

We have explored the kinetic effect of increasing electron transfer (ET) distance in a biomimetic, proton-coupled electron-transfer (PCET) system. Biological ET often occurs simultaneously with proton (PT) order to avoid high-energy, charged intermediates resulting from stepwise protons and electrons. These concerted proton-electron-transfer (CPET) reactions are implicated numerous biological pathways. In many cases, PT is coupled long-range ET. While studies shown that rate sensitive...

Using dye-sensitized water-splitting photoelectrochemical cells is a promising way to satisfy an increasing demand for energy without significant production of greenhouse gases. These commonly utilize large band gap nanoparticulate semiconductor photoelectrode that sensitized with photoactive dye. In this paper, we study SnO2 nanoparticles (NPs) are either ruthenium-based dye (RuP) or porphyrin-based (Por). dyes have significantly different molar extinction coefficient, resulting in high...

Interfacial electron transfer (IET) dynamics in dye-sensitized SnxTi1–xO2 (x = 0, 0.25, 0.50, 0.75, and 1) were investigated using ultrafast transient absorption spectroscopy, linear DFT calculations. We found that altering the composition of allows for monotonic tunability conduction band, both driving force forward IET electronic states band involved IET. from a prototypical ruthenium(II) polypyridyl dye sensitizer can be tuned by modulating spectrum adsorbed acceptor band. Periodic...

We present Terahertz (THz) measurements of dl-norvaline (dl-Nva) organic molecular crystals. This material undergoes a solid-state phase transition when the temperature is reduced to less than 180 K. The low and room phases have different THz absorption spectra, which allows them be distinguished. A better understanding mechanism gained by studying influence crystal grain size as well effect doping dl-Nva crystals with other amino acids.

DL-Norvaline is a molecular crystal at room temperature and it undergoes phase transition when cooled below 190 K.This believed to be Martensitic.We investigate this by measuring its terahertz (THz) spectrum over range of temperatures.Temperature-dependent THz time-domain spectroscopy (THz-TDS) measurements reveal that the (T β→α ) K.The influence nucleation seeds was analyzed determining T crystals with varying grain size.Grains 5 µm or less result in lower = 180 K) compared larger grains...

We have explored the kinetic effect of increasing electron transfer distance in a biomimetic, proton coupled system (PCET). Biological is often simultaneous with order to avoid high-energy, charged intermediates resulting from stepwise protons and electrons. These concerted (CPET) reactions are implicated numerous biological pathways. In many cases, long-range transfer. While studies shown that rate sensitive between donor acceptor, extensions CPET sparse. The possibility unique dependence...

Terahertz (THz) spectroscopy is an excellent non-contact electrical probe of charge injection and conductivity with sub-picosecond time resolution. One may exploit this capability to study a variety materials, here we choose the transient photoconductivity tungsten (VI) oxide (WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ), wide band gap metal oxide. This semiconductor interest in renewable energy research artificial photosynthesis...

We have explored the kinetic effect of increasing electron transfer distance in a biomimetic, proton coupled system (PCET). Biological is often simultaneous with order to avoid high-energy, charged intermediates resulting from stepwise protons and electrons. These concerted (CPET) reactions are implicated numerous biological pathways. In many cases, long-range transfer. While studies shown that rate sensitive between donor acceptor, extensions CPET sparse. The possibility unique dependence...