The Effect of Calcinations Temperature on the Performance of TiO2 Aggregates-Based Dye Solar Cells (DSCs)

2011 ◽  
Vol 364 ◽  
pp. 248-253 ◽  
Author(s):  
Nur Azella Zaine Siti ◽  
Muti Mohamed Norani ◽  
Mohamad Azmi Bustam
Keyword(s):  
Conversion Efficiency ◽  
Chemical Properties ◽  
Energy Conversion Efficiency ◽  
Synthesis Process ◽  
Solar Simulator ◽  
Electron Generation ◽  
Physico Chemical ◽  
Vis Spectroscopy ◽  
Dye Solar Cells ◽  
Hydrolysis Of

Development of novel TiO2 nanostructures as the photo-electrode material is one possible solution to control the competition between electron generation and recombination which is the main constraint of obtaining higher conversion efficiency of dye solar cell (DSC). By manipulating the synthesis process, desired TiO2 nanostructure with specific properties can be obtained to enhance solar energy conversion efficiency. In this study, the effect of calcinations temperature towards physico-chemical properties of synthesized TiO2 aggregates and their influence on overall light conversion efficiency of DSC has been investigated. TiO2 aggregates (0.45 µm) composing of nanocrystallites (10-40 nm), were synthesized through hydrolysis of dilute titanium alkoxide in ethanol. The synthesized samples have been characterized using FESEM, XRD and UV-Vis spectroscopy. DSCs were then assembled and evaluated using solar simulator under 100 mW/cm2 illuminations. The size of nanocrystallites was found to increase with increasing calcinations temperature where the 500°C produced the 21 nm sized nanocrystallites, the optimum size for highest absorption of the dye resulting in the highest efficiency. TiO2 aggregates-based DSC demonstrated better performance compared to nanoparticles (P-25)-based DSC. This is attributed to the enhanced scattering introduced by micron-sized aggregates.

Optimized TiO2 Nanocrystallites Aggregates for Enhanced Efficiency in Dye Solar Cells

2014 ◽  
Vol 917 ◽  
pp. 35-44 ◽  
Author(s):  
Siti Nur Azella Zaine ◽  
Norani Muti Mohamed ◽  
Mohamad Azmi Bustam
Keyword(s):  
Solar Cells ◽  
Light Scattering ◽  
Water Content ◽  
Calcination Temperature ◽  
Conversion Efficiency ◽  
Internal Surface Area ◽  
Solar Simulator ◽  
Vis Spectroscopy ◽  
Dye Solar Cells ◽  
28 Nm

TiO2 aggregates-based dye solar cells (DSCs) have gained an increasing attention due to their enhanced harvesting of light radiance. The capability of this photoelectrode material is attributed to the submicron spherical aggregates that introduce light scattering effect which can generate more electrons whilst high internal surface area for dye chemisorption is provided by nanocrystallites which made up the aggregates. Here, TiO2 aggregates (0.45-0.20 μm) composing of nanocrystallites (10-28 nm) with desired physicochemical properties for enhanced overall light conversion efficiency of DSC were synthesized by varying the water content in the hydrolysis of titanium alkoxide in ethanol and calcination temperature. TiO2 aggregates obtained were characterized using FESEM, XRD and UV-Vis spectroscopy. The assembled DSCs were then evaluated using solar simulator under AM 1.5 (100 mW/cm2) simulated sunlight. With higher water content in the hydrolysis process, the aggregates reduce in size and lose their spherical shapes resulting in lower absorption intensity indicating the occurrence of low light scattering in the TiO2 film. Nanocrystallites were found to have an increasing size of 12 nm to 28 nm with increasing calcination temperature of 400°C to 700°C. Sample of aggregates calcined at 450°C recorded the highest efficiency (~4%). Highest conversion efficiency was observed for DSC that used well-defined spherical TiO2 aggregates composing of nanocrystallites which were synthesized at optimum synthesis parameter which is by using ethanol with low water content (0.9 vol%) followed by calcination at 450°C. Thus, optimized TiO2 nanocrystallites which form spherical aggregate is critical in order to improve light harvesting efficiency of DSCs.

Albumen-mediated Green Synthesis of ZnFe2O4 Nanoparticles and Their Physico-Chemical Properties

2021 ◽  
Vol 14 (5) ◽  
pp. 445-449
Keyword(s):  
Zinc Ferrite ◽  
Single Phase ◽  
Chemical Properties ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
Scanning Microscope ◽  
Physico Chemical ◽  
Znfe2o4 Nanoparticles ◽  
Photoluminescence Studies ◽  
Combustion Technique

Abstract: Spinel ferrites with general formula AB2O4 possess charming magnetic and electrical properties owing to their thermal and chemical steadfastness. Spinel zinc ferrite (ZnFe2O4) nanoparticles have attracted massive attention due to their unusual amalgamation of properties, especially magnetic properties, where these properties are equipped as suitable candidates in the field of electronics. Here, a simple self-combustion technique is made with the assistance of albumen to synthesize nanocrystalline zinc ferrite (ZnFe2O4) particles. The egg white (albumen) that is used in the synthesis process plays the fuel role in the process of combustion. The results of the powder X-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FTIR) suggested that the synthesized nanoparticles are of single phase and show spinel structure. The photoluminescence studies reported a doublet peak at around 360-380 nm. The functional groups present in the synthesized nanoparticles were revealed from FTIR data. EDX findings give an account of the percentage composition of the elements Fe, Zn and O present in the synthesized sample. High-resolution Scanning Microscope (HRSEM) reveals the agglomerated coalescence nature of ferrite nanoparticles. Keywords: Ferrite, PXRD, FTIR, HRSEM, EDX Albumen.

scholarly journals Tryptic phosphopeptides from whole casein. II. Physicochemical properties related to the solubilization of calcium

1989 ◽  
Vol 56 (3) ◽  
pp. 335-341 ◽  
Author(s):  
Rafael Berrocal ◽  
Serge Chanton ◽  
Marcel A. Juillerat ◽  
Blaise Favillare ◽  
Jean-Claude Scherz ◽  
...  
Keyword(s):  
Binding Sites ◽  
Calcium Phosphates ◽  
Chemical Properties ◽  
Sodium Caseinate ◽  
Ph Values ◽  
Physico Chemical ◽  
Casein Phosphopeptides ◽  
Hydrolysis Of ◽  
Phosphate Solutions ◽  
Tryptic Hydrolysis

SummaryCasein phosphopeptides (GPP) were produced by tryptic hydrolysis of sodium caseinate and further purified by precipitation and chromatography on QAE-Sephadex A-25. Their physico-chemical properties were compared with the properties of an enzymically dephosphorylated equivalent preparation (DPP). Binding of Ca2+ to the peptides was measured using a Ca selective electrode and was found to increase with pH and to show 1/1 stoicheiometry Ca/Porg in CPP at pH 6·5 a.nd 7·6. Klotz plots indicated equivalent binding sites at these two pH values, but some heterogeneity was seen at pH 3·5. In contrast, DPP did not bind significant amounts of Ca2+.CPP effectively inhibited the formation of insoluble calcium phosphates at different Ca/P ratios. The effective CPP concentration was 10 mg/1 and complete stability of calcium phosphate solutions was obtained at about 100 mg/1. This stabilizing effect was dependent on the presence of organic P.

A Novel Polyaniline Nanocomposite with Doping Effects of Poly(Methyl Methacrylate) and TiO2 Nanoparticles

2016 ◽  
Vol 44 ◽  
pp. 281-292 ◽  
Author(s):  
Unathi Sidwaba ◽  
Usisipho Feleni ◽  
Hlamulo Makelane ◽  
Ezo Nxusani ◽  
Lindsay Wilson ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Titanium Dioxide Nanoparticles ◽  
Conductive Polymer ◽  
Chemical Properties ◽  
Poly Methyl Methacrylate ◽  
Wave Voltammetry ◽  
Physico Chemical ◽  
Doping Effects ◽  
Vis Spectroscopy ◽  
Polyaniline Nanocomposite

Polyaniline (PANI) is a globally investigated conductive polymer with a variety of applications in various fields due to its ease of synthesis and modification. One method of enhancing the physico-chemical properties and processability of PANI is the incorporation of polymers and nanoparticles to form composite and hybrid materials with new features. This study reports the electrochemical synthesis of a polyaniline nanocomposite that incorporates titanium dioxide nanoparticles (TiO2) and poly (methyl methacrylate) (PMMA). The significant effects of PMMA and TiO2 nanoparticles on structural, morphological, optical and electrochemical properties of native polyaniline were investigated using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, cyclic voltammetry (CV) and square wave voltammetry (SWV). The formation and deformation of relevant peaks observed from the FTIR spectra confirm the intrusion of PMMA and TiO2 into PANI while the voltammetric results show that the incorporation of both dopants significantly enhanced the electroactivity of PANI in a neutral pH medium.

Effects of non-ionic surfactants on the uptake and hydrolysis of fluoresceindiacetate by alkane-oxidizing bacteria

2000 ◽  
Vol 46 (4) ◽  
pp. 387-390 ◽  
Author(s):  
Per Bruheim ◽  
Kjell Eimhjellen
Keyword(s):  
Cell Surface ◽  
Uptake Rate ◽  
Biological Effects ◽  
Quantitative Difference ◽  
Chemical Properties ◽  
Ionic Surfactants ◽  
Physico Chemical ◽  
Hydrolysis Of

Biological effects of non-ionic surfactants on alkane-oxidizing bacteria were studied by assessing their influence on the uptake of prefluorochrome fluoresceindiacetate (FDA) and its intracellular hydrolysis to fluorescein. Both decreasing and increasing rates of hydrolysis as a consequence of the presence of surfactants were observed. The surfactants influenced the uptake of FDA, but not its intracellular hydrolysis. The effects of the surfactants on the uptake rate depended strongly on the structure and physico-chemical properties of the surfactants. There was no qualitative or significant quantitative difference in surfactant susceptibility between induced (alkane grown) and non-induced bacteria (acetate grown), even though the induced cells possess greater cell surface hydrophobicity.Key words: fluoresceindiacetate, bacteria, surfactants, alkane.

scholarly journals Ni(II) Butylmethyldithiocarbamate: Physico-Chemical Properties, X-Ray Crystallography, DFT and Anti-Corrosion Screening in Different Acids

2021 ◽  
Vol 16 ◽  
pp. 1-11
Author(s):  
Nor Farah Hida Othman ◽  
Noor Syafiqah Habdul Latif ◽  
Sheikh Ahmad Izzadin Sheikh Mohd Ghazali ◽  
Erna Normaya Abdullah ◽  
Nur Nadia Dzulkifli
Keyword(s):  
Fourier Transform ◽  
Chemical Properties ◽  
Attenuated Total Reflection ◽  
X Ray ◽  
Loss Analysis ◽  
X Ray Crystallography ◽  
Industrial Sectors ◽  
Physico Chemical ◽  
Vis Spectroscopy ◽  
Acid Environment

In industrial sectors, pickling and acid cleaning are mutual processes where acid solutions, such as hydrochloric acid (HCl) and sulfuric acid (H2SO4), are used to eliminate the corrosion products yielded on metal surfaces; thus, improving the performance of the machineries. However, the usage of the acid could lead to another metal deterioration. Dithiocarbamate inhibitor is defined as an organic compound that has good corrosion inhibition properties that can work as an inhibitor in an acid environment. Dithiocarbamate (DTC) assists by reducing acid reactiveness which prohibits metal dissolution in the acid. In this study, the Ni(II) N-butylmethyldithiocarbamate (Ni[BuMedtc]2) complex was synthesised by using an in-situ method and characterised by elemental analyser, attenuated total reflection Fourier transform infrared (ATR-FTIR), ultraviolet-visible (UV-Vis) spectroscopy and X-ray crystallographic study, and the chemical properties of the Ni[BuMedtc]2 complex was successfully calculated by the Discrete Fourier Transform (DFT) approach. The experimental results which were obtained through the weight-loss analysis method in two different acids – 1 M HCl and 1 M H2SO4 – indicated that the inhibition efficiency increased as the inhibitor concentration increased. The outcome showed that the Ni[BuMedtc]2 performed better as an inhibitor in 1 M HCl as compared to in1 M H2SO4 to protect the metal exterior because H2SO4 is more corrosive due to the excessive presence of H+.

scholarly journals Bactericidal Effect of Cotton Fabric Treated with Polymer Solution Containing Silver Nanoparticles of Different Sizes and Shapes

2020 ◽  
Vol 32 (6) ◽  
pp. 1335-1342
Author(s):  
Kh. E. Yunusov ◽  
A.A. Sarymsakov ◽  
S.V. Mullajonova ◽  
F.M. Turakulov ◽  
S. Sh. Rashidova
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Properties ◽  
Bactericidal Effect ◽  
Cotton Fabrics ◽  
Sodium Carboxymethylcellulose ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Vis Spectroscopy ◽  
Silver Nitrate Concentration

Stable silver nanoparticles in solutions of sodium-carboxymethylcellulose (Na-CMC) were synthesized and their structure and physico-chemical properties were evaluated. The form and sizes of silver nanoparticles formed in solutions of CMC and cotton fabrics were studied using UV-VIS spectroscopy, atomic force microscopy and transmission electron microscopy methods. It was found that silver nitrate concentration increase in sodium carboxymethylcellulose solutions, as well as photoirradiation of the hydrogel lead to the changes of the silver nanoparticles size and shape. Investigations have also shown that spherical silver nanoparticles with sizes of 5-35 nm and content of 0.0086 mass% in cotton fabrics possess high bactericidal activity. Stabilization of silver nanoparticles has preserved bactericidal and bacteriostatic activities during the washing of cotton fabrics and textiles on their base.

Graded Multilayered TiO2 Photoelectrode for Improving the Performance of Dye Solar Cells

2013 ◽  
Vol 756 ◽  
pp. 190-196 ◽  
Author(s):  
Adel Eskandar Samsudin ◽  
Muti Mohamed Norani
Keyword(s):  
Conversion Efficiency ◽  
Electrochemical Impedance ◽  
Bottom Layer ◽  
Multilayered Structure ◽  
Glass Electrode ◽  
Tio2 Electrode ◽  
Solar Simulator ◽  
Dye Solar Cells ◽  
Composite Configuration ◽  
The One

Numerous research have been conducted to improve the efficiency of dye solar cell (DSC) through the study on its components namely the dye, electrolyte, counter electrode and the photoelectrode material. This paper presents the study on the usage of a multilayered structure with different composition of TiO2 nanoparticles/aggregates composites starting with the top layer consisting of purely aggregates and ending with the bottom layer consisting of wholly nanoparticles as the photoelectrode material. The graded composition profile of increasing amount of aggregates at the top of the photoelectrode and increasing amount of nanoparticles at the bottom of the photoelectrode will allow for the enhancement in the optical properties and kinetics of DSC. The layers were screen-printed onto FTO coated glass substrate to form the photoelectrodewith an active area of 1 cm2 and thickness of 12 µm. The N719 dye-coated TiO2 electrode was then assembled into sandwich configuration with platinized conducting glass electrode and injected with iodide/tri-iodide redox couples electrolyte.Kinetics and the underlying transport properties of the assembled DSCs were measured by Electrochemical Impedance Spectroscopy (EIS). The response of the cells towards a spectrum of light frequencies was measured using Incident Photon to Electron Conversion Efficiency (IPCE). Conversion efficiency was measured using a 100 mW/cm2 solar simulator. Highest efficiency was found for the multilayered photoelectrode configuration at 4.58% with 14% improvement over the DSC with pure aggregate.DSCs with the multilayered composite configuration have higher current density, Jscwith an increase of 2.249 mA cm-1 compared to the one with only nanoparticles and only aggregates layer. Multilayer configuration has shown significant improvement in the quantum efficiency by exhibiting higher light absorption especially in the range of 500-550 nm light wavelength by about 12.9%.The increase in the conversion efficiency of DSCs with multilayer configuration is also attributed to the improvement in the electron diffusion as evident by the EIS measurement.

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