International Journal of PhotoenergyThis is an RSS file. You can use it to subscribe to this data in your favourite RSS reader, such as GoogleReader, or to display this data on your own website or blog. Subscribe to this data using MyMedWorm.Subscribe to this data using GoogleReader.Subscribe to this data using Bloglines.Subscribe to this data using MyYahoo.

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98 records returned

Optical Study on Poly(methyl methacrylate)/Poly(vinyl acetate) BlendsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Transparent films of poly(methyl methacrylate)/poly(vinyl acetate) blend with different concentrations were prepared by using solution-cast technique. FT-IR transmission spectra were carried for the samples to detect the influence of UV radiation. In addition, optical absorption measurements were carried out for the samples at room temperature across the 190–900 nm wavelength regions before and after exposure to UV and filtered radiation using xenon arc lamp. The study has been also extended to include the changes in the optical parameters including the band tail width and band gap energies for the samples. Mo...
Source: International Journal of Photoenergy - November 10, 2009 Category: Chemistry Source Type: journals

Prospects of Nanostructure-Based Solar Cells for Manufacturing Future Generations of Photovoltaic ModulesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We present a comprehensive review on prospects for one-, two-, or three-dimensional nanostructure-based solar cells for manufacturing the future generation of photovoltaic (PV) modules. Reducing heat dissipation and utilizing the unabsorbed part of the solar spectrum are the key driving forces for the development of nanostructure-based solar cells. Unrealistic assumptions involved in theoretical work and the tendency of stretching observed experimental results are the primary reasons why quantum phenomena-based nanostructures solar cells are unlikely to play a significant role in the manufacturing of future generations of ...
Source: International Journal of Photoenergy - November 9, 2009 Category: Chemistry Source Type: journals

Photocatalytic Activity in CH3CN Related to the Surface Properties of TiO2 Powders Prepared by Sol-Gel MethodEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Some TiO2 powders, prepared from titanium(IV)tetraisopropoxide by the sol-gel method and thermally treated between 100 and 1000∘C, have been characterized by X-ray powder diffraction and by nitrogen adsorption and desorption at 77 K to calculate the BET-specific surface area, from which the micropore volume and the external surface area can be derived. The photocatalytic activity (ka) of the above powders has been evaluated considering the TiO2-sensitized photo-oxidation of 4-methoxybenzyl alcohol in CH3CN as the test reaction. The decrease of ka have been related to the decrease of the BET surface area, the ...
Source: International Journal of Photoenergy - November 4, 2009 Category: Chemistry Source Type: journals

Investigation of Temperature and Aging Effects in Nanostructured Dye Solar Cells Studied by Electrochemical Impedance SpectroscopyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Effects of aging and cyclically varying temperature on the electrical parameters of dye solar cells were analyzed with electrochemical impedance spectroscopy. Photoelectrode total resistance increased as a function of time due to increasing electron transport resistance in the TiO2 film. On the other hand, photoelectrode recombination resistance was generally larger, electron lifetimes in the TiO2 were film longer, and charge transfer resistance on the counter electrode was smaller after the temperature treatments than before them. These effects correlated with the slower deterioration rate of the temperature-treated cells...
Source: International Journal of Photoenergy - November 2, 2009 Category: Chemistry Source Type: journals

Investigation of Temperature and Aging Effects in Nanostructured Dye Solar Cells Studied by Electrochemical Impedance SpectroscopysEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Effects of aging and cyclically varying temperature on the electrical parameters of dye solar cells were analyzed with electrochemical impedance spectroscopy. Photoelectrode total resistance increased as a function of time due to increasing electron transport resistance in the TiO2 film. On the other hand, photoelectrode recombination resistance was generally larger, electron lifetimes in the TiO2 were film longer, and charge transfer resistance on the counter electrode was smaller after the temperature treatments than before them. These effects correlated with the slower deterioration rate of the temperature-treated cells...
Source: International Journal of Photoenergy - October 29, 2009 Category: Chemistry Source Type: journals

Analysis of Humid Air Turbine Cycle with Low- or Medium-Temperature Solar EnergyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A new humid air turbine cycle that uses low- or medium-temperature solar energy as assistant heat source was proposed for increasing the mass flow rate of humid air. Based on the combination of the first and second laws of thermodynamics, this paper described and compared the performances of the conventional and the solar HAT cycles. The effects of some parameters such as pressure ratio, turbine inlet temperature (TIT), and sollar collector efficiency on humidity, specific work, cycle's exergy efficiency, and solar energy to electricity efficiency were discussed in detail. Compared with the conventional HAT cycle, beca...
Source: International Journal of Photoenergy - October 29, 2009 Category: Chemistry Source Type: journals

From 1 Sun to 10 Suns c-Si Cells by Optimizing Metal Grid, Metal Resistance, and Junction DepthEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Use of a solar cell in concentrator PV technology requires reduction in its series resistance in order to minimize the resistive power losses. The present paper discusses a methodology of reducing the series resistance of a commercial c-Si solar cell for concentrator applications, in the range of 2 to 10 suns. Step by step optimization of commercial cell in terms of grid geometry, junction depth, and electroplating of the front metal contacts is proposed. A model of resistance network of solar cell is developed and used for the optimization. Efficiency of unoptimized commercial cell at 10 suns drops by 30% of its 1 sun...
Source: International Journal of Photoenergy - October 18, 2009 Category: Chemistry Source Type: journals

Impedance and Interface Properties of Al/Methyl-Red/p-InP Solar CellEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
An Al/methyl-red/p-InP solar cell was fabricated via solution-processing method and was characterized by using current-voltage (I-V) and capacitance-voltage-frequency (C-V-f) measurements at room temperature. From dark I-V characteristics, the values of ideality factor and barrier height of the device were calculated as 1.11 eV and 2.02, respectively. It has been seen that the device exhibited a good photovoltaic behavior with a maximum open circuit voltage Voc of 0.38 V and short-circuit current Isc of 2.8 nA under only 200 lx light intensity. The barrier height and acceptor carrier concent...
Source: International Journal of Photoenergy - October 15, 2009 Category: Chemistry Source Type: journals

Photoelectrocatalytic Degradation of Organic Pollutants in Aqueous Solution Using a Pt-TiO2 FilmEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A series of Pt-TiO2 films with nanocrystaline structure was prepared by a procedure of photodeposition and subsequent dip-coating. The Pt-TiO2 films were characterized by X-ray diffraction, scanning electronic microscope, electrochemical characterization to examine the surface structure, chemical composition, and the photoelectrochemical properties. The photocatalytic activity of the Pt-TiO2 films was evaluated in the photocatalytic (PC) and photoelectrocatalytic (PEC) degradation of formic acid in aqueous solution. Compared with a TiO2 film, the efficiency of formic acid degradation using the Pt-TiO2 films was significant...
Source: International Journal of Photoenergy - September 10, 2009 Category: Chemistry Source Type: journals

From Laboratory Studies to the Field Applications of Advanced Oxidation Processes: A Case Study of Technology Transfer from Switzerland to Burkina Faso on the Field of Photochemical Detoxification of Biorecalcitrant Chemical Pollutants in WaterEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The Fenton and photo-Fenton detoxification of non-biodegradable chemical pollution in water was investigated under simulated UV light in the laboratory and under direct sunlight in Ouagadougou, Burkina Faso. The laboratory experiments enable one to make a systematic diagnosis among three types of wastewaters, identifying a biorecalcitrant wastewater containing the Chloro-hydroxy-Pryridine (CHYPR). The application of the photo-Fenton process on effluent containing the CHYPR showed not to stimulate the generation of biodegradable by-products. Optimal conditions for detoxification of effluent containing the CHYPR were found a...
Source: International Journal of Photoenergy - August 18, 2009 Category: Chemistry Source Type: journals

Removal of Organic Impurities from Water Using a Reactor with Photoactive RefillEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The aim of the presented work was the removal of phenol from water using a reactor with photoactive refill. Titanium dioxide (Chemical Factory “Police” Poland) was immobilized on the base material as a thin layer from the alcoholic suspension followed by thermal stabilization. The glass fabric was applied as a support for the titania coating. The results of studies revealed that the titania coatings show a high photocatalytic activity toward the phenol decomposition in water. The complete removal of phenol was achieved in the relatively short time of 23 hours. The prepared coatings exhibit high stability in re...
Source: International Journal of Photoenergy - August 18, 2009 Category: Chemistry Source Type: journals

Study of Dye-Sensitized Solar Cells by Scanning Electron Micrograph Observation and Thickness Optimization of Porous TiO2 ElectrodesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In order to improve the photoenergy conversion efficiency of dye-sensitized solar cells (DSCs), it is important to optimize their porous TiO2 electrodes. This paper examines the surface and cross-sectional views of the electrodes using scanning electron micrography. Two types of samples for cross-sectional viewing were prepared by mechanically breaking the substrate and by using an Ar-ion etching beam. The former displays the surface of the TiO2 particles and the latter shows the cross-section of the TiO2 particles. We found interesting surface and cross-sectional structures in the scattering layer containing the 400Ȁ...
Source: International Journal of Photoenergy - August 18, 2009 Category: Chemistry Source Type: journals

Generation of Useful Hydrocarbons and Hydrogen during Photocatalytic Decomposition of Acetic Acid on CuO/Rutile PhotocatalystsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The presented studies have focused on a photocatalytic generation of useful hydrocarbons, mainly methane and ethane, from acetic acid under N2 atmosphere. CuO-loaded rutile, as well as unmodified rutile and anatase-phase TiO2 photocatalysts were applied in the experiments. The efficiency of the catalysts towards methane generation changed in the following order: Cu-TiO2 (10% Cu) > crude TiO2≈Cu-TiO2 (20% Cu) > Cu-TiO2 (5% Cu) > rutile. The amount of CH4 produced in the presence of the catalyst containing 10 wt% of Cu was higher for ca. 33&#...
Source: International Journal of Photoenergy - August 18, 2009 Category: Chemistry Source Type: journals

The Effect of UV-Irradiation (under Short-Circuit Condition) on Dye-Sensitized Solar Cells Sensitized with a Ru-Complex Dye Functionalized with a (diphenylamino)Styryl-Thiophen GroupEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A new ruthenium complex, cis-di(thiocyanato)(2,2′-bipyridine-4,4′-dicarboxylic acid)(4,4′-bis(2-(5-(2-(4-diphenylaminophenyl)ethenyl)-thiophen-2-yl)ethenyl)-2,2′-bipyridine)ruthenium(II) (named E322) has been synthesized for use in dye-sensitized solar cells (DSCs). Higher extinction coefficient and a broader absorption compared to the standard Ru-dye, N719, were aimed. DSCs were fabricated with E322, and the efficiency was 0.12% initially. (4.06% for N719, as reference). The efficiency was enhanced to 1.83% by exposing the cell under simulated sunlight containing UV-irradiation at s...
Source: International Journal of Photoenergy - August 18, 2009 Category: Chemistry Source Type: journals

Photocatalytic Activity of TiO2-WO3 CompositesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
TiO2-WO3 photocatalysts were prepared in a vacuum evaporator by impregnation of TiO2 with WO2 dissolved in an H2O2 solution (30%) and followed by calcination at 400 and 600∘C. XRD analyses showed that at 400∘C monoclinic phase of WO3 was dominated whereas at 600∘C both monoclinic and regular phases of WO3 were present. Modification of TiO2 by WO3 caused increasing in the absorption of light to the visible range. TiO2 and photocatalysts modified with low amount of WO3 (1–5 wt.%) showed high adsorption of Acid Red (AR) on their surface and enhanced photocatalytic activity under UV i...
Source: International Journal of Photoenergy - August 18, 2009 Category: Chemistry Source Type: journals

Acylated 2-(N-arylaminomethylene)benzo[b]thiophene-3(2H)-Ones: Molecular Switches with Varying Migrants and SubstituentsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Synthesis and properties of photochromic acylated 2-(N-arylaminomethylene)benzo[b]thiophene-3(2H)-ones are described. Their structure largely depends on the nature of acyl migrant and in a less degree on N-aryl substituent. (Source: International Journal of Photoenergy)
Source: International Journal of Photoenergy - August 18, 2009 Category: Chemistry Source Type: journals

Growth of GaN@InGaN Core-Shell and Au-GaN Hybrid Nanostructures for Energy ApplicationsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We demonstrated a method to control the bandgap energy of GaN nanowires by forming GaN@InGaN core-shell hybrid structures using metal organic chemical vapor deposition (MOCVD). Furthermore, we show the growth of Au nanoparticles on the surface of GaN nanowires in solution at room temperature. The work shown here is a first step toward engineering properties that are crucial for the rational design and synthesis of a new class of photocatalytic materials. The hybrid structures were characterized by various techniques, including photoluminescence (PL), energy dispersive x-ray spectroscopy (EDS), transmission and scanning ele...
Source: International Journal of Photoenergy - August 18, 2009 Category: Chemistry Source Type: journals

Synthesis of Novel Iono- and Photochromic Spiropyrans Derived from 6,7-Dihydroxy-8-Formyl-4-Methyl-2H-Chromene-2-OneEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Novel photochromic spiropyrans (SPPs) containing 6′-hydroxy group were synthesized and their spectral properties as well as abilities for complexation with metal ions studied. In solutions they exist as equilibrium mixture of spirocyclic (A) and merocyanine (B) isomers. The largest content of merocyanine form was found for the derivative with an electron-donating methyl group in position 5 of hetaryl fragment. The irradiation of SPPs in acetonitrile shifts the equilibrium to the B form. Similar effect causes the addition of metal cations due to formation of colored complexes with merocyanine isomers. (Source: Intern...
Source: International Journal of Photoenergy - August 18, 2009 Category: Chemistry Source Type: journals

Squaraine Planar-Heterojunction Solar CellsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The photovoltaic performance of squaraine-based organic solar cells is investigated. Two squaraine derivatives with extraordinarily high extinction coefficients are used as electron donors in bilayer heterojunctions with fullerene C60 as electron acceptor. Due to the very strong squaraine absorption band in the red spectral domain, antibatic behavior due to light filtering is observed in the photocurrent spectrum for film thicknesses of 35 nm to 40 nm. At reduced film thicknesses of 20 nm, this filtering effect at maximum absorption can be alleviated and power conversion efficiencies under simulated AM...
Source: International Journal of Photoenergy - August 18, 2009 Category: Chemistry Source Type: journals

Performance Analysis of a Photovoltaic-Thermal Integrated SystemEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The present commercial photovoltaic solar cells (PV) converts solar energy into electricity with a relatively low efficiency, less than 20%. More than 80% of the absorbed solar energy is dumped to the surroundings again after photovoltaic conversion. Hybrid PV/T systems consist of PV modules coupled with the heat extraction devices. The PV/T collectors generate electric power and heat simultaneously. Stabilizing temperature of photovoltaic modules at low level is higly desirable to obtain efficiency increase. The total efficiency of 60–80% can be achieved with the whole PV/T system provided that the T sys...
Source: International Journal of Photoenergy - June 25, 2009 Category: Chemistry Source Type: journals

Naphthoxy Bounded Ferrocenium Salts as Cationic Photoinitiators for Epoxy PhotopolymerizationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
To improve the absorption and the bulk of arene ligands, two naphthoxy bounded ferrocenium salts as new cationic photoinitiators, (η6-α-naphthoxybenzene) (η5-cyclopentadienyl) iron hexafluorophosphate (NOFC-1) and (η6-β-naphthoxybenzene) (η5-cyclopentadienyl) iron hexafluorophosphate (NOFC-2), were synthesized, characterized, and studied. NOFC-1 and NOFC-2 were prepared by the reaction of nucleophilic substitution (SNAr) with naphthol and chlorobenzene-cyclopentadienyliron salt. Their activity as cationic photoinitiators was studied using real-time infrared spectroscopy. The result...
Source: International Journal of Photoenergy - June 25, 2009 Category: Chemistry Source Type: journals

Nanosized TiO2 Photocatalyst Powder via Sol-Gel Method: Effect of Hydrolysis Degree on Powder PropertiesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Nanosized TiO2 powder was synthesized via sol-gel method using titanium tetraisopoxide (TPT) as the precursor. Mol ratios of water to TPT were varied from 1 (Powder A), 2 (Powder B), 3 (Powder C), and 4 (Powder D) to evaluate effect of hydrolysis degree. TG/DTA curves showed that amorphous phase turned to anatase crystal structure at ca. 415, 337, 310, and 339∘C for Powders A, B, C, and D, respectively. XRD analysis showed that all the synthesized TiO2 powders were 100% in anatase form with Powders B and C showing considerably higher crystallinities. The powders obtained at lower water to TPT mol ratios were sph...
Source: International Journal of Photoenergy - June 25, 2009 Category: Chemistry Source Type: journals

Electrochemical Investigation of Doped Titanium DioxideEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Thin films of transition-metal doped (0.2, 1.0, and 5.0 atom%) TiO2 were prepared on titanium foil using a sol-gel route catalyzed by ammonium acetate. Dopants investigated were the fourth-period transition metals. The prepared films were characterised by Raman spectroscopy, Auger electron spectroscopy, and photoelectrochemical methods. The films doped with transition metals showed a lower photocurrent response than undoped samples. No major red shift in the photocurrent response spectra of the doped films was observed. A photocurrent response was observed under visible light irradiation of the samples and was p...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Gas-Phase Photodegradation of Decane and Methanol on TiO2: Dynamic Surface Chemistry Characterized by Diffuse Reflectance FTIREmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to study illuminated TiO2 surfaces under both vacuum conditions, and in the presence of organic molecules (decane and methanol). In the presence of hole scavengers, electrons are trapped at Ti(III)–OH sites, and free electrons are generated. These free electrons are seen to decay by exposure either to oxygen or to heat; in the case of heating, reinjection of holes into the lattice by loss of sorbed hole scavenger leads to a decrease in Ti(III)–OH centers. Decane adsorption experiments lend support to the theory that ...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

A Photocatalytic Active Adsorbent for Gas Cleaning in a Fixed Bed ReactorEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Efficient photocatalysis for gas cleaning purposes requires a large accessible, illuminated active surface in a simple and compact reactor. Conventional concepts use powdered catalysts, which are nontransparent. Hence a uniform distribution of light is difficult to be attained. Our approach is based on a coarse granular, UV-A light transparent, and highly porous adsorbent that can be used in a simple fixed bed reactor. A novel sol-gel process with rapid micro mixing is used to coat a porous silica substrate with TiO2-based nanoparticles. The resulting material posses a high adsorption capacity and a photocatalytic activity...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Diffusion Enhanced Upconversion in Organic SystemsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The upconverted fluorescence generation in a solution of multicomponent organic systems has been studied as a function of the temperature to investigate the role of resonant energy transfer processes and of the molecular diffusion on the overall emission yield. The strong blue emission observed exciting the samples at 532 nm derives from a bimolecular triplet-triplet annihilation between 9,10 diphenylanthracene molecules, which produces singlet excited states from which the higher energy emission takes place. Diphenylanthracene excited triplet states are populated by energy transfer from a phosphorescent donor (Pt(...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Preparation of NaTaO3 by Spray Pyrolysis and Evaluation of Apparent Photocatalytic Activity for Hydrogen Production from WaterEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
NaTaO3 photocatalyst was prepared by spray pyrolysis process and tested as photocatalyst for water splitting under UV light. Precursor solution was prepared from NaNO3 and Ta(OC2H5)5 in nitric acid solution and spray-pyrolyzed in air at between 973 and 1273 K. Considerable enhancement of photocatalytic activity was achieved by loading 0.05∼0.2 wt% of NiO on the surface of NaTaO3. The NiO loading was more effective on the NaTaO3 synthesized by spray pyrolysis in comparison with that synthesized by solid-state reaction. The quantum yield (QY) of NiO/NaTaO3 photocatalyst was measured by chemical actin...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Versatile Bottom-Up Approach to Nanostructured Functional Materials for Optoelectronic ApplicationsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A versatile strategy to load ordered mesoporous silica-based materials with functional molecular building blocks in order to obtain host-guest systems exhibiting specific functions is described. Optical microscope examination of the obtained material confirms that the addition of a chromophoric moiety to the reaction mixture is not detrimental in achieving the desired macroscopic morphology of the silica particles. A micro-photoluminescence investigation of the obtained material gave strong evidence that both surfactant micelles and the porous oxide matrix preserve the spectral features of the included molecular species in...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Synthesis of Visible-Light-Activated Yellow Amorphous TiO2 PhotocatalystEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Visible-light-activated yellow amorphous TiO2 (yam-TiO2) was synthesised by a simple and organic-free precipitation method. TiN, an alternative precursor for TiO2 preparation, was dissolved in hydrogen peroxide under acidic condition (pH∼1) adjusted by nitric acid. The yellow precipitate was obtained after adjusting pH of the resultant red brown solution to 2 with NH4OH. The BET surface area of this sample was 261 m2/g. The visible light photoactivity was evaluated on the basis of the photobleaching of methylene blue (MB) in an aqueous solution by using a 250 W metal halide bulb equipped with UV cutof...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

One Dimensional Polymeric Organic Photonic Crystals for DFB LasersEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We present a very simple method to realize a one-dimensional photonic crystal (1D PC), consisting of a dye-doped polymeric multilayer. Due to the high photonic density of states at the edges of the photonic band-gap (PBG), a surface emitting distributed feedback (DFB) laser is obtained with this structure. Furthermore, the incidence angle dependence of the PBG of the polymeric multilayer is reported. (Source: International Journal of Photoenergy)
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

TiO2 Nanoparticles-Photocatalytic Oxidation of Selected CycloalkanolsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Photocatalytic oxidation of cyclohexanol (1), cyclopentanol (2), and cycloheptanol (3) was investigated by using titanium dioxide (Degussa P25) as a semiconductor photocatalyst .The effect of different operational parameters such as the catalyst, the solvent, time, and oxidant was also studied. Results showed a high percentage of conversion for 1–3 (71.6%, 94.2%, and 100%, resp.) and that the primary photocatalytic oxidation products are the corresponding cycloalkanones (4–6). They were formed with high selectivity (>85%). Several other products were also identified using GC, GC/MS techni...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Photocatalyzed Degradation of a Pesticide Derivative Glyphosate in Aqueous Suspensions of Titanium DioxideEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The photocatalytic degradation of a herbicide derivative, glyphosate [(N-phosphonomethyl) glycine] has been investigated in aqueous suspensions of titanium dioxide at different pH values. This compound was found to degrade more efficiently under alkaline pH, where no adsorption takes place on the surface of the catalyst in the dark. The main degradation route involves the cleavage of the P–C bond giving rise to sarcosine and glycine as the intermediate products formed during the photooxidation process. (Source: International Journal of Photoenergy)
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Sunlight-Initiated Photochemistry: Excited Vibrational States of Atmospheric ChromophoresEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Atmospheric chemical reactions are often initiated by ultraviolet (UV) solar radiation since absorption in that wavelength range coincides to typical chemical bond energies. In this review, we present an alternative process by which chemical reactions occur with the excitation of vibrational levels in the ground electronic state by red solar photons. We focus on the O–H vibrational manifold which can be an atmospheric chromophore for driving vibrationally mediated overtone-induced chemical reactions. Experimental and theoretical O–H intensities of several carboxylic acids, alcohols, and peroxides are presented....
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Analysis of Surface Texturization of Solar Cells by Molecular Dynamics SimulationsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The purpose of this paper is to develop a simple new model, based on the classic molecular dynamics simulation (MD), alternative to complex electron-photon interactions to analyze the surface texturization of solar cells. This methodology can easily propose the absorptance differences between texturing and nontexturing solar cells. To verify model feasibility, this study simulates square, pyramidal, and semicircular texturization surfaces. Simulations show that surface texturization effectively increases the absorptance of incident light for solar cells, and this paper presents optimal texturization shapes. The MD model ca...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Studies of Dye Sensitisation Kinetics and Sorption Isotherms of Direct Red 23 on TitaniaEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Sorption kinetics and isotherms have been measured for a commercial dye (Direct Red 23) on different samples of powdered Titania, and the data were analysed to better understand the dye sensitization process for dye sensitised solar cells (DSSCs). For the sorption kinetics, the data show rapid initial sorption (<1 hour) followed by slower rate of increasing uptake between 1 and 24 hours. While higher initial concentrations of dye correspond to higher sorption overall, less dye is absorbed from higher initial dye concentrations when considered as percentage uptake. The correlation between the sorption data and model iso...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Microstructured Reactors Designed by Stereolithography and Characterized by Fluorescent ProbesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The main objective of this research was to define a structured and functionalized support for future biomedical applications (model of “low-density bioarray”). The experiments were carried out by using stereolithography process with a special SU-8 photoresist and the reproducibility of the method was studied by analyzing the surface profile of the support. Finally, a matrix of regular controlled sized wells was fabricated. Chemical reactions leading to covalent grafting were run to demonstrate that the inner surface of the wells remains still reactive after polymerization. The grafting of fluorophores with carb...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Doped TiO2 Nanomaterials and ApplicationsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
(Source: International Journal of Photoenergy)
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Photochemistry Aspects of the Laser Pyrolysis Addressing the Preparation of Oxide Semiconductor PhotocatalystsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The laser pyrolysis is a powerful and a versatile tool for the gas-phase synthesis of nanoparticles. In this paper, some fundamental and applicative characteristics of this technique are outlined and recent results obtained in the preparation of gamma iron oxide (γ-Fe2O3) and titania (TiO2) semiconductor nanostructures are illustrated. Nanosized iron oxide particles (4 to 9 nm diameter values) have been directly synthesized by the laser-induced pyrolysis of a mixture containing iron pentacarbonyl/air (as oxidizer)/ethylene (as sensitizer). Temperature-dependent Mossbauer spectroscopy shows that mainly ma...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Biocidal Silver and Silver/Titania Composite Films Grown by Chemical Vapour DepositionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This paper describes the growth and testing of highly active biocidal films based on photocatalytically active films of TiO2, grown by thermal CVD, functionally and structurally modified by deposition of nanostructured silver via a novel flame assisted combination CVD process. The resulting composite films are shown to be highly durable, highly photocatalytically active and are also shown to possess strong antibacterial behaviour. The deposition control, arising from the described approach, offers the potential to control the film nanostructure, which is proposed to be crucial in determining the photo and bioactivity of th...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Electro-Optical and Electrochemical Properties of a Conjugated Polymer Prepared by the Cyclopolymerization of Diethyl DipropargylmalonateEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The electro-optical and electrochemical properties of poly(diethyl dipropargylmalonate) were measured and discussed. Poly(diethyl dipropargylmalonate) prepared by (NBD)PdCl2 catalyst was used for study. The chemical structure of poly(diethyl dipropargylmalonate) was characterized by such instrumental methods as NMR (1H-, 13C-), IR, and UV-visible spectroscopies to have the conjugated cyclopolymer backbone system. The microstructure analysis of polymer revealed that this polymer have the six-membered ring moieties majorly. The photoluminescence peak of polymer was observed at 543 nm, which is corresponded to the phot...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Photocatalytic Degradation of a Water Soluble Herbicide by Pure and Noble Metal Deposited TiO2 Nanocrystalline FilmsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We present the photocatalytic degradation of a water soluble sulfonylurea herbicide: azimsulfuron in the presence of titania nanocrystalline films. Efficient photodegradation of herbicide was achieved by using low-intensity black light tubes emitting in the Near-UV. The degradation of the herbicide follows first-order kinetics according to the Langmuir-Hinshelwood model. Intermediate products were identified by the LC-MS-MS technique during photocatalytic degradation. In order to increase photodegradation rate of the herbicide, we examined the effect of titania modification by depositing noble metals at various quantities ...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Synthesis of High-Thermal Stable Titanium Dioxide NanoparticlesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Nanosized crystals of anatase phase TiO2 with high-thermal stability was synthesized in the range of 15–17 nm via sol-gel method using titanium n-butoxide precursor. Synthesize was done at two different temperatures, that is, 200 and 300∘C and the final products were calcined at 400∘C. The final products were characterized by N2 adsorption, X-ray diffraction, FT-IR, and TEM and tested in a photoreactor using fluorescien as model molecule. For thermal stability investigation, the sample prepared at 300∘C was heated up to 800, 850, and 900∘C, the XRD results showed that the synthesize...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Electrochemiluminescence Study of Europium (III) Complex with Coumarin3-Carboxylic AcidEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The europium (III) complex of coumarin-3-carboxylic acid (C3CA) has been prepared and characterized on the basis of elemental analysis, IR, and emission (photoluminescence and electrochemiluminescence) spectroscopy. The synthesised complex having a formula Eu(C3CA)2(NO3)(H2O)2 was photophysically characterized in solution and in the solid state. Electrochemiluminescence, ECL, of the system containing the Eu(III)/C3CA complex was studied using an oxide-covered aluminium electrode. The goal of these studies was to show the possibility of the use of electrochemical excitation of the Eu(III) ion in aqueous solution for emissio...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Two-Dimensional Free Energy Surfaces for Electron Transfer Reactions in SolutionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Change in intermolecular distance between electron donor (D) and acceptor (A) can induce intermolecular electron transfer (ET) even in nonpolar solvent, where solvent orientational polarization is absent. This was shown by making simple calculations of the energies of the initial and final states of ET. In the case of polar solvent, the free energies are functions of both D-A distance and solvent orientational polarization. On the basis of 2-dimensional free energy surfaces, the relation of Marcus ET and exciplex formation is discussed. The transient effect in fluorescence quenching was measured for several D-A pairs in a ...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Novel Photocatalytic Reactor Development for Removal of Hydrocarbons from WaterEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Hydrocarbons contamination of the marine environment generated by the offshore oil and gas industry is generated from a number of sources including oil contaminated drill cuttings and produced waters. The removal of hydrocarbons from both these sources is one of the most significant challenges facing this sector as it moves towards zero emissions. The application of a number of techniques which have been used to successfully destroy hydrocarbons in produced water and waste water effluents has previously been reported. This paper reports the application of semiconductor photocatalysis as a final polishing step for the remov...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Analysis of Pyramidal Surface Texturization of Silicon Solar Cells by Molecular Dynamics SimulationsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, the large tilted angle leads to the lower efficiency of solar cell. To consider the effect of incident angle, a range of high efficiency exists due to the increasing probability of second reflection. Furthermore, the azimuth angle of incident light also affects the efficiency of solar cells. Our results agree well with previous studies. This MD model can potentially be used to predict the efficiency promotion in any optical reflection-absorption cases. (Source: International Journal of Photoenergy)
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Durability of Ag-TiO2 Photocatalysts Assessed for the Degradation of Dichloroacetic AcidEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The stability of Ag-TiO2 photocatalysts was examined for the photocatalytic degradation of dichloroacetic acid (DCA) as a function of the recycling times. The photocatalytic activity was investigated by measuring the rate of H+ ions released during the photodegradation of DCA and confirmed by measuring the total organic carbon removal. The photodegradation reactions were studied at pH 3 and pH 10 for a series of Ag-TiO2 photocatalysts as different with Ag loadings . All the Ag-TiO2 and bare TiO2 photocatalysts showed a decrease in photocatalytic activity on recycling for the DCA photodegradation reaction. The decrease in a...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Preface to the Special Issue on Selected Papers from the Second International Conference on Semiconductor Photochemistry SP-2Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
(Source: International Journal of Photoenergy)
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Polymer Photovoltaic Cell Using TiO2/G-PEDOT Nanocomplex Film as ElectrodeEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Using TiO2/G-PEDOT (PEDOT/PSS doped with glycerol) nanocomplex film as a substitute for metal electrode in organic photovoltaic cell is described. Indium tin oxide (ITO) worked as cathode and TiO2/G-PEDOT nanocomplex works as anode. The thickness of TiO2 layer in nanocomplex greatly affects the act of this nonmetallic electrode of the device. To enhance its performance, this inverted organic photovoltaic cell uses another TiO2 layer as electron selective layer contacted to ITO coated glass substrates. All films made by solution processing techniques are coated on the transparent substrate (glass) with a conducting film ITO...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals

Nonlinear Modelling of Kinetic Data Obtained from Photocatalytic Mineralisation of 2,4-Dichlorophenol on a Titanium Dioxide MembraneEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Photomineralisation of 2,4-dichlorophenol (DCP) in aqueous solutions (10.0–100.0 mg/L of C) was systematically studied at 318±3 K, in an annular laboratory-scale reactor, by photocatalytic membranes immobilizing titanium dioxide, as a function of substrate concentration, and absorbed power per unit length of membrane. Kinetics of both substrate disappearance, to yield intermediates, and total organic carbon (TOC) disappearance, to yield carbon dioxide, were followed (first series of experiments). At a fixed value of irradiance (1.50 W⋅cm−1), other series of mineralization ex...
Source: International Journal of Photoenergy - June 10, 2009 Category: Chemistry Source Type: journals