Quantum dot sensitized solar cells (QDSCs) have attracted significant attention as promising third-generation photovoltaic devices. In the form of quantum dots (QDs), semiconductor sensitizers very useful and often tunable properties; moreover, their theoretical thermodynamic efficiency might be high 44%, better than original 31% calculated ceiling. Unfortunately, practical performance these devices still lags behind that dye-sensitized cells. this Account, we summarize strategies for...

Solar cells based on a mesoporous structure of TiO2 and the polysulfide redox electrolyte were prepared by direct adsorption colloidal CdSe quantum dot light absorbers onto oxide without any particular linker. Several factors cooperate to improve performance quantum-dot-sensitized solar cells: an open wide bandgap electron collector, which facilitates higher covering internal surface with sensitizer, passivation reduce recombination improved counter electrode materials. As result, 1.83%...

We have investigated the sensitization of nanoporous titanium dioxide by previously synthesized CdSe quantum dots (QDs) protected with trioctylphosphine. Covering TiO2 films QDs has been achieved using two strategies: (i) direct adsorption from dichoromethane dispersions and (ii) anchoring through a molecular linker, concretely, mercaptopropionic acid (MPA). In contrast MPA-mediated adsorption, leads to high degree QD aggregation, as revealed atomic force microscopy (AFM) images obtained...

Several of the multiple applications titanium dioxide nanomaterials are directly related to introduction or generation charge carriers in oxide. Thus, electrochemistry plays a central role understanding factors that must be controlled for optimization material each application. Herein, main conceptual tools needed address study electrochemical properties TiO(2) nanostructured electrodes reviewed, as well methods prepare and modify them. Particular attention is paid dark response these its...

Colloidal CdSe quantum dots (QDs) of different sizes, prepared by a solvothermal route, have been employed as sensitizers nanostructured TiO(2) electrode based solar cells. Three bifunctional linker molecules used to attach colloidal QDs the surface: mercaptopropionic acid (MPA), thioglycolic (TGA), and cysteine. The molecule plays determinant role in cell performance, illustrated fact that incident photon charge carrier generation efficiency (IPCE) could be improved factor 5-6 using...

Among the third-generation photovoltaic devices, much attention is being paid to so-called Quantum Dot sensitized Solar Cells (QDSCs). The currently poor performance of QDSCs seems be efficiently patched by ZnS treatment, increasing output parameters albeit its function remains rather unclear. Here new insights into role layer on QDSC are provided, revealing simultaneously most active recombination pathways. Optical and AFM characterization confirms that deposit covers, at least partially,...

We have combined in situ photoelectrochemical and spectroscopic techniques (Attenuated Total Reflection Infrared, ATR-IR, Resonance Raman Spectroscopy) for the study of charge-transfer complex formed upon adsorption catechol on anatase nanoparticles contact with aqueous acidic solutions. Vibrational spectroscopies reveal existence at least two adsorbate configurations: catecholate a chelate configuration molecularly adsorbed catechol, apparent values −12.3 −10.5 kJ mol-1, respectively. These...

The dependence on temperature of the voltammetric behavior Pt(111), Pt(100), and Pt(110) electrodes in 0.1 M HClO4 has been studied. A thermodynamic analysis hydrogen underpotential deposition (HUPD) carried out, taking into account that adsorption process is accompanied by changes electrode double layer. for Pt(100) requires a previous deconvolution OH contribution whereas Pt(110), limited to high H coverages. Pt−H bond energy values obtained Pt(hkl) agree with UHV. On Pt(111) Δ linearly...

A kinetic model based on a set of reactions occurring at the illuminated semiconductor/electrolyte junction, under current multiplication (doubling) and external applied bias (absence recombination), was developed as tool for assessing mechanistic aspects photoelectrochemical oxidation water-dissolved pollutants. The allows to distinguish whether direct or indirect interfacial hole transfer solute predominates. We apply photooxidation aqueous solutions formic acid methanol polycrystalline...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydrogen evolution on platinum single crystal surfaces: effects of irreversibly adsorbed bismuth and antimony hydrogen adsorption (100)R. Gomez, A. Fernandez-Vega, J. M. Feliu, AldazCite this: Phys. Chem. 1993, 97, 18, 4769–4776Publication Date (Print):May 1, 1993Publication History Published online1 May 2002Published inissue 1 1993https://pubs.acs.org/doi/10.1021/j100120a032https://doi.org/10.1021/j100120a032research-articleACS PublicationsRequest...

We sought to determine the site of action and receptor type responsible for antihypertensive actions rilmenidine. an oxazoline analogue clonidine. In anesthetized paralyzed rats decerebration did not alter dose dependent reductions in arterial pressure heart rate elicited by i.v. drug. Rilmenidine microinjected bilaterally into C1 area rostral ventrolateral medulla (RVL), but nucleus tractus solitarii (NTS) nor caudal (CVL), dose-dependent falls at doses order magnitude less than required...

The effect of temperature on the voltammetric OH adsorption Pt(111) and Pt(100) electrodes in perchloric acid media has been studied. From a thermodynamic analysis based generalized isotherm, ΔG°, ΔH°, ΔS° values for have determined. On Pt(111), enthalpy ranges between −265 −235 kJ mol-1, becoming less exothermic as coverage increases. These are reasonable agreement with experimental data calculated same reaction gas phase. entropy from −200 J mol-1 K-1 (low coverage) to −110 (high...

The dependence of the potential zero charge (pzc) for Pt(111) surfaces in acidic aqueous solution having increasing densities ordered monoatomic steps (111)−(110) and (111)−(100) zones is evaluated from CO "charge-displacement" measurements, with objective elucidating influence electrochemical double layer on large step-induced changes surface known clean uncharged ultrahigh vacuum (UHV). This experimental strategy, which involves evaluating flowing at controlled potentials upon "quenching"...

For monocrystalline TiO2 electrodes, capacitive currents are observed at potentials that negative enough to induce the filling of conduction band states. Nanoparticulate electrodes exhibit, apart from these currents, an additional pair peaks more positive potentials, which can be attributed charge traps in gap. We have taken advantage well-defined morphology and crystal structure three different types rutile investigate nature gap In particular, nanostructured films composed oriented wires,...

Quantum dot sensitized solar cells have the potentiality to emerge as viable third-generation photovoltaic devices. In these cells, photoanode is constituted by a nanostructured oxide layer visible suitable quantum dots (QDs). Here, we report on some aspects of sensitization titanium dioxide nanoparticulate electrodes with CdSe QDs deposited so-called successive ionic adsorption and reaction (SILAR) method. Parallel SILAR experiments rutile single crystal indicate that an almost full...

The performance of quantum dot (QD) sensitized solar cells depends mainly on both electron injection from the QDs to oxide matrix and recombination rates. Here we show a direct correlation between ultrafast carrier dynamics photoanode (and complete cell) performance. TiO2 nanoparticulate electrodes with colloidal CdSe are prepared by either or linker-assisted adsorption (using cysteine, p-mercaptobenzoic acid, mercaptopropionic acid). These examined dynamics, photopotential, incident...

Photovoltaic devices comprising metal chalcogenide nanocrystals as light-harvesting components are emerging a promising power-generation technology. Here, we report strategy to evenly deposit Sb2Se3 nanoparticles on mesoporous TiO2 confirmed by Raman spectroscopy, energy-dispersive X-ray spectrometry, and transmission electron microscopy. Detailed study of the interfacial charge transfer dynamics means transient absorption spectroscopy provides evidence injection across Sb2Se3/TiO2 interface...