A facile method for the preparation of silver nanoparticles (AgNPs) various sizes and morphologies, including dodecahedra, nanorods, nanoplates, has been discovered. By choosing desired optical properties (absorption maximum) irradiating spherical AgNP seeds with a selected light emitting diode, we achieve control over size, morphology, properties. The AgNPs are intrinsically dependent on size shape particles, which can be readily controlled strategies reported here. Literature methods...

A dual nature of the excited state CH₃NH₃PbI₃ perovskites is discovered, which fully identifies spectral features in transient spectroscopy.

The optimal size of spherical silver nanoparticles (AgNPs) for off-resonance surface-enhanced Raman scattering (SERS) was found to be ∼50 nm based on the equivalent Ag content in AgNP colloids. It is understood that SERS intensity adsorbates surface metal dependent and shape particles interest. Herein, we report a seeded growth mechanism formation allows superior control over resultant with relatively low polydispersity. high degree better understanding study effect particle intensity....

Glutathione-protected gold clusters exhibit size-dependent excited state and electron transfer properties. Larger-size (e.g., Au25GSH18) with core-metal atoms display rapid (<1 ps) as well slower relaxation (∼200 ns) while homoleptic Au10–12GSH10–12) only relaxation. These decay components have been identified metal–metal transition ligand-to-metal charge transfer, respectively. The short lifetime component becomes less dominant the size of cluster decreases. long-lived ability to...

Gold superatom nanoclusters stabilized entirely by N-heterocyclic carbenes (NHCs) and halides are reported. The reduction of well-defined NHC-Au-Cl complexes produces clusters comprised an icosahedral Au13 core surrounded a symmetrical arrangement nine NHCs three chlorides. X-ray crystallography shows that the characterized multiple CH-π π-π interactions, which rigidify ligand likely contribute to exceptionally high photoluminescent quantum yields observed, up 16.0%, is significantly greater...

The optical and electronic properties of quantum dots (QDs), which are drastically affected by their size, have a major impact on performance in devices such as solar cells. We now report the size-dependent cell for CuInS2 QDs capped with 1-dodecanethiol. Pyramidal shaped diameters between 2.9 5.3 nm been synthesized assembled mesoscopic TiO2 films electrophoretic deposition. Time-resolved emission transient absorption spectroscopy measurements ascertained role internal surface defects...

Bismuth vanadate (BiVO4) with a band gap of ∼2.4 eV has emerged as one the visible photocatalysts that can absorb light below 520 nm. The electron/hole pairs are generated following BiVO4 excitation effective for water splitting, especially when is combined other metal oxides such WO3. We report solution processed method designing transparent WO3/BiVO4 heterojunction electrodes and observe synergistic effect on photoelectrochemical activity WO3/BiVO4, system performing dramatically better...

Varying the halide ratio (e.g., Br–:I–) is a convenient approach to tune bandgap of organic lead perovskites. The complexation between Pb2+ and ions primary step in dictating overall composition, optical properties annealed perovskite structure. Br– nearly 7 times greater than I–, thus making dominant binding species mixed systems. Emission transient absorption measurements show strong dependence excited state behavior on composition employed precursor solution. When excess (X = I–) are...

This perspective highlights advances in the preparation and understanding of metal nanoclusters stabilized by organic ligands with a focus on N-heterocyclic carbenes (NHCs). We demonstrate need for clear relationship between NHC properties their resulting nanocluster structure properties. emphasize importance balancing stability introduction reactive sites catalytic applications better how these clusters interact environments effective use biological applications. The impact atom-scale...

The excited-state behavior of luminescent gold clusters provides new insights in understanding their photocatalytic activity the visible region. excited state glutathione-protected nanoclusters (AuGSH), which is characterized by long-lived (τ = 780 ns), arises from ligand-to-metal type transition. These AuGSH are a partially oxidized (Au(I)) and readily reduced chemical or electrochemical methods. Interestingly, metal core transition with short-lived lifetime < 3 ps) appears along longer...

The Norrish type I photocleavage is an excellent source of strongly reducing free radicals that can be used to convert soluble metal ions into their atomic state proceed form nanoparticles. Proton coupled electron transfer (PCeT) a useful tool interpret the mechanism for ion reduction, process in these systems involves multisite PCeT, with proton and having separate receiving substrates.

Cu-deficient CuInS2 quantum dots (QDs) synthesized by varying the [Cu]:[In] ratio allow modulation of optical properties as well identification radiative emission pathways. Absorption and spectral features showed a strong dependence on CuxInS2 QDs, indicating two independent transitions. These effects are pronounced in transient absorption spectra. The bleaching band edge broad tail bands subpicosecond–nanosecond time scale provide further evidence for dual recombination process monitored...

Due to its ∼2.4 eV band gap, BiVO4 is a very promising photoanode material for harvesting the blue portion of solar light photoelectrochemical (PEC) water splitting applications. In WO3/BiVO4 heterojunction films, electrons photoexcited in are injected into WO3, overcoming lower charge carriers' diffusion properties limiting PEC performance photoanodes. Here, we investigate by ultrafast transient absorption spectroscopy carrier interactions occurring at interface between two oxides systems...

Glutathione-capped gold nanoclusters (Aux-GSH NCs) are anchored along with a sensitizing squaraine dye on TiO2 surface to evaluate the cosensitizing role of Au(x)-GSH NCs in dye-sensitized solar cells (DSSCs). Photoelectrochemical measurements show an increase photoconversion efficiency DSSCs when both sensitizers present. The observed photoelectrochemical improvements cosensitized more than additive effects as evident from photovoltage (ΔV high 0.24 V) Electron equilibration and...

In this Perspective, we explore the opportunities that plasmon excitation may offer for practitioners in organic chemistry. Beyond interesting physical properties and lively colors of colloidal solutions noble metal nanostructures, transitions can trigger a variety processes, from simple heat delivery with pinpoint precision, to enhanced generation excited states immediate vicinity nanoparticle, electron- hole-transfer processes readily participate photoredox processes. understanding how...

Electricity has been generated from evaporation-driven water flow in films of carbon soot particles and other porous media. This paper reports the placement nanofiber mats (CNMs) on fiberglass screens for construction efficient water-evaporation-induced generators (WEIGs). These CNMs are prepared carbonizing electrospun polyacrylonitrile then treating them with oxygen plasma. After electrode attachment to two ends a CNM, one is immersed into water. Water rises mat due capillary action...

Herein, we describe the synthesis of a toroidal Au

Abstract Photochemistry is a powerful tool for controlled synthesis of metal nanoparticles, their modification and in many the applications that these materials have. Plasmon transitions offer unique way delivering energy with exquisite spatial temporal control can be used to advantage where visible wavelength required. This account research at University Ottawa summarizes details synthesis, silver nanostructures.

Multiferroics, materials that exhibit coupling between spontaneous magnetic and electric dipole ordering, have significant potential for high-density memory storage the design of complex multistate elements. In this work, we demonstrated solvent-controlled synthesis Cr(3+)-doped BaTiO(3) nanocrystals investigated effects size doping concentration on their structure phase transformation using X-ray diffraction Raman spectroscopy. The properties these were studied by susceptibility, circular...

Electrical power can be extracted from interactions at the interface of water/materials, known as "hydrovoltaic" phenomenon. Devices based on this emerging technology hold a lot promise for meeting renewable energy demands, but materials reported to date largely require specific weather conditions, such low humidity (∼10-30%), thus hindering widespread application. Herein, we report new use plates thin layer chromatography (TLC) that provide continuous support capillary-driven water flow....

The recent discovery of hydrovoltaic devices for power generation has led to a rapid growth into new materials harvesting energy specifically this research field. Of the investigated, carbon have dominated, and graphene oxide (GO) emerged as leader. While graphite is conductive, it does not functional groups strongly interact with water, highly functionalized GO forms strong interaction water generate necessary surface charges but typically high conductivity. Herein, we report fabrication...

Silver clusters too small to support a plasmon band possess interesting fluorescence properties as well being convenient route studying the early stages of nanoparticle formation. Fluorescent silver are synthesized in toluene solution, and formation is monitored herein by laser flash photolysis (LFP). Kinetic analysis Ag consistent with smallest possible clusters, dimers (Ag(2)), whereby mechanism for these provided first reported extinction coefficient association constant Ag(0) form Ag(2)....

Porphyrin aggregates have attractive photophysical properties for phototherapy and optical imaging, including quenched photosensitization, efficient photothermal conversion, unique absorption spectra. Although hydrophobic porphyrin photosensitizers long been encapsulated into liposomes drug delivery, little is known about the membrane of with large amphiphilic compositions. In this paper, a porphyrin-lipid conjugate was incorporated formed saturated or unsaturated lipids to study...