scholarly journals Evaluation of performance characteristics of nano TiO2 and TiO2-ZnO composite for DSSC applications and electrochemical determination of potassium ferrocyanide using cyclic voltammetry

2021 ◽  
Vol 8 (12) ◽  
pp. 125004
Author(s):  
H A Deepa ◽  
G M Madhu ◽  
B E Kumara Swamy

Abstract Nanoparticles of TiO2 and TiO2-ZnO composite (2:1 molar ratio) were synthesized utilizing the sol-gel and solution combustion approaches, respectively. Scanning electron microscopic, energy dispersive x-ray, x-ray diffraction, UV-visible spectroscopy, and Brunauer–Emmett–Teller analysis were employed to characterize the synthesized nanoporous TiO2 and the composite of TiO2-ZnO nanoparticles. Fabrication of dye-sensitized solar cells (DSSCs) was carried out by incorporating the synthesized nanoporous materials coating on the photoanodes using the doctor blade technique. Nano TiO2 and the composite of TiO2-ZnO were also analyzed using cyclic voltammetry test, and their performance was compared for the electrochemical detection of potassium ferrocyanide. The composite of TiO2-ZnO exhibited better electrocatalytic activity in comparison with the pure TiO2 nanoparticles. The fabricated DSSCs by employing nano TiO2 particles and TiO2-ZnO composite as the semiconductor photoanode materials were compared for photovoltaic performance. The DSSC fabricated with TiO2 nanoparticles exhibited better photovoltaic performance with an efficiency of 2.22% and a current density of 4.152 mA cm−2 than that fabricated with TiO2-ZnO composite with an efficiency of 0.0022% and a short circuit current density of 0.014 mA cm−2.

2017 ◽  
Vol 80 (1) ◽  
Author(s):  
Zainal Arifin ◽  
Sudjito Soeparman ◽  
Denny Widhiyanuriyawan ◽  
Suyitno Suyitno ◽  
Argatya Tara Setyaji

Natural dyes have attracted much researcher’s attention due to their low-cost production, simple synthesis processes and high natural abundance. However the dye-sensitized solar cells (DSSCs) based natural dyes have higher tendency to degradation. This article reports on the enhancement of performance and stability of dye-sensitized solar cells (DSSCs) using natural dyes. The natural dyes were extracted from papaya leaves by ethanol solvent at a temperature of 50 °C. Then the extracted dyes were isolated and modified into Mg-chlorophyll using column chromatography. Mg-chlorophyll was then synthesized into Fe-chlorophyll to improve stability. The natural dyes were characterized using ultraviolet-visible spectrometry, Fourier transform infrared spectroscopy, and cyclic voltammetry. The performance of DSSCs was tested using a solar simulator. The results showed the open-circuit voltage, the short-circuit current density, and the efficiency of the extracted papaya leaves-based DSSCs to be 325 mV, 0.36 mA/cm2, and 0.07%, respectively. Furthermore, the DSSCs with purified chlorophyll provide high open-circuit voltage of 425 mV and short-circuit current density of 0.45 mA/cm2. The use of Fe-chlorophyll for sensitizing the DSSCs increases the efficiency up to 2.5 times and the stability up to two times. The DSSCs with Fe-chlorophyll dyes provide open-circuit voltage, short-circuit current density, and efficiency of 500 mV, 0.62 mA/cm2, and 0.16%, respectively. Further studies to improve the current density and stability of natural dye-based DSSCs along with an improvement in the anchor between dyes and semiconducting layers are required.


2020 ◽  
Vol 1 (8) ◽  
pp. 2964-2970
Author(s):  
Venkatesan Srinivasan ◽  
Jagadeeswari Sivanadanam ◽  
Kothandaraman Ramanujam ◽  
Mariadoss Asha Jhonsi

The inclusion of CNMs together with TiO2 enhanced the short circuit current density by 31% and power conversion efficiency (PCE) by 46% compared to the CNM-free DSSCs.


2021 ◽  
Author(s):  
Mohd Arif Dar ◽  
D. Govindarajaran ◽  
Gulam Nabi Dar

Abstract In this paper, Tin Sulfide (SnS) nanoparticles is synthesized with three different solvents through hydrothermal method and characterized by using X-Ray diffraction, scanning electron microscopy, UV–Drs spectroscopy, Fourier transform infrared spectroscopy, Energy Dispersive X- ray spectrum, Supercapcitor and photovoltaic performance. XRD patterns indicate that the prepared SnS nanoparticles exist in the orthorhombic phase. The SEM analysis clearly picturize the morphological changes in the SnS nanoparticles synthesized through different solvents. The UV-Drs spectrum gives direct energy band gap which lies between 1.0 eV to 2.0 eV. The FT-IR spectrum explains various functional groups present in the SnS nanoparticles. The prepared SnS counter electrodes (CEs) showed good electrocatalytic activity in the redox reaction of the I−/I3−. The efficiency of SnS-e, SnS-a and SnS-m counter electrodes are 9.99 %, 9.90 % and 9.86 % in Dye-sensitized solar cells (DSSC) than that of platinum counter electrode which is 9.80 %. The specific capacitance of 284 F/g is obtained for SnS-e electrode at a current density of 5 A/g and an energy density of 216 Wh/kg corresponding to power density value of 1.6 KWh/kg which proves SnS-e electrode possesses better capacitive performance.


2013 ◽  
Vol 802 ◽  
pp. 84-88
Author(s):  
Sagulthai Kahatta ◽  
Nopsiri Chaiyo ◽  
Chesta Ruttanapun ◽  
Wicharn Techitdheera ◽  
Wisanu Pecharapa ◽  
...  

The microwave-assisted solution combustion synthesis was applied to the initial synthesizing of Ca3Co2O6powder using glycine as a fuel and nitrate as an oxidant. The as-synthesized powders were calcined at 700-1,000ºC for 4h. Product characterization was performed using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Scanning electron microscope (SEM). The fuel-to-oxidizer molar ratio was found to affect the combustion reaction and character of the powder obtained. The phase composition of powder after calcination at various temperatures has shown that the formation of Ca3Co2O6occurs directly. The calcined powder possesses a rhombohedral crystal structure with an X-ray diffraction pattern that could be matched with the Ca3Co2O6JCPDS: 89-0629. This method is a simple way of synthesizing fine Ca3Co2O6powder with a low calcination temperature.


Author(s):  
Arifa Batool ◽  
Syed Mujtaba Shah ◽  
Naimat Ullah ◽  
Hazrat Hussain

Abstract Cadmium oxide nanoparticles (NPs) were successfully synthesized through the simple and low-cost sol–gel method. The optical, morphological, compositional, and structural properties of as-synthesized NPs were investigated by ultraviolet–visible (UV/Vis) spectroscopy, fluorescence spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analysis. Absorption spectra of CdO NPs were used for band gaps calculation, which was found to be 2.11 eV. The XRD pattern was used to investigate the purity and crystalline nature of NPs. Morphology and elemental composition were investigated by using SEM and energy-dispersive X-ray spectroscopy (EDX), respectively. FTIR assisted in identifying the functional groups and grafting of the dye on the surface of NPs. These CdO nanoparticles were photosensitized with Ru (II) based Z907 dye. Z907 dye was employed to extend the absorption spectrum of the material to the visible region of the solar spectrum so as to harvest the maximum amount of solar influx on the surface of earth. The energy level diagram revealed that the interaction among the constituents of the nanohybrid assembly permitted the flow of the electron in a cascade manner from dye to CdO nanoparticles. The synthesized photoactive nanohybrid material was thoroughly blended with poly (3-hexylthiophene), a solid electrolyte, and I–V measurements under simulated radiations 1000 W/m2 (AM 1.5) were recorded. A maximum induced photon to the current conversion efficiency of 0.60% was achieved.


Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1532 ◽  
Author(s):  
Tharmakularasa Rajaramanan ◽  
Muthukumarasamy Natarajan ◽  
Punniamoorthy Ravirajan ◽  
Meena Senthilnanthanan ◽  
Dhayalan Velauthapillai

In this study, P25-titanium dioxide (TiO2) was doped with ruthenium (Ru) by systematically varying the Ru content at 0.15, 0.30, 0.45 and 0.6 mol%. The synthesized Ru-doped TiO2 nanomaterials have been characterized by X-ray diffraction (XRD), Raman spectroscopy, energy-dispersive X-ray (EDX) analysis, UV-visible (UV–Vis) spectroscopy, and electrochemical impedance (EIS) spectroscopy. The XRD patterns of undoped and Ru-doped TiO2 nanomaterials confirm the presence of mixed anatase and rutile phases of TiO2 while EDX spectrum confirms the presence of Ti, O and Ru. Further, UV-visible absorption spectra of doped TiO2 nanomaterial reveal a slight red shift on Ru-doping. The short circuit current density (JSC) of the cells fabricated using the Ru-doped TiO2 photoanode was found to be dependent on the amount of Ru present in TiO2. Optimized cells with 0.3 mol% Ru-doped TiO2 electrodes showed efficiency which is 20% more than the efficiency of the control cell (η = 5.8%) under stimulated illumination (100 mWcm−2, 1 sun) with AM 1.5 filter. The increase in JSC resulted from the reduced rate of recombination upon doping of Ru and this was confirmed by EIS analysis.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Parth Bhatt ◽  
Kavita Pandey ◽  
Pankaj Yadav ◽  
Brijesh Tripathi ◽  
Manoj Kumar

This paper investigates the effect of ageing on the performance of dye-sensitized solar cells (DSCs). The electrical characterization of fresh and degraded DSCs is done under AM1.5G spectrum and the current density-voltage (J-V) characteristics are analyzed. Short circuit current density (JSC) decreases significantly whereas a noticeable increase in open circuit voltage is observed. These results have been further investigated electroanalytically using electrochemical impedance spectroscopy (EIS). An increase in net resistance results in a lower JSC for the degraded DSC. This decrease in current is mainly due to degradation of TiO2-dye interface, which is observed from light and dark J-V characteristics and is further confirmed by EIS measurements. A reduction in the chemical capacitance of the degraded DSC is observed, which is responsible for the shifting of Fermi level with respect to conduction band edge that further results in an increase of open circuit voltage for the degraded DSC. It is also confirmed from EIS that the degradation leads to a better contact formation between the electrolyte and Pt electrode, which improves the fill factor of the DSC. But the recombination throughout the DSC is found to increase along with degradation. This study suggests that the DSC should be used under low illumination conditions and around room temperature for a longer life.


2010 ◽  
Vol 1260 ◽  
Author(s):  
Mariyappan Shanmugam ◽  
Braden Bills ◽  
Mahdi Farrokh Baroughi

AbstractThe short circuit density (JSC) and open circuit voltage (VOC) of dye sensitized solar cells (DSSCs) were improved from 9.8 to 17.8 mA/cm2 and 728 to 743 mV by depositing an ultra thin SiO2 layer on mesoporous TiO2 using Atomic Layer Deposition (ALD) method. X ray photoelectron spectroscopy confirmed the growth of SiO2 on mesoporous TiO2 surface. It was also observed that the enhancement in DSSC performance highly depends on the thickness of the ALD grown SiO2 layers on mesoporous TiO2. Compared to the reference DSSC which used untreated TiO2, incorporation of 5 ALD cycles (about 5 atomic layers) of SiO2 on mesoporous TiO2 resulted in 80 % enhancement (E) in the photoconversion efficiency from 4 to 7.2%. It is believed that the deposition of the ultra thin SiO2 film on mesoporous TiO2 modifies the density and activity of the surface states and an optimized layer thickness (5 cycles) leads to significant improvement in the DSSC performance. The enhanced photovoltaic performance was confirmed by dark and illuminated I-V and external quantum efficiency (EQE) measurements.


Author(s):  
Sevil ŞENER

The synthesis and spectroscopic characterization of an innovative ball-type cobalt (II)  metallophthalocyanine 4, bridged by four 1,2-bis(2-hydroxymethyl)-O-carborane (HMOC) 1 units has been achieved. The structure of 4 was characterized via elemental analysis, UV–visible absorption spectroscopy, FT-IR spectroscopy, and MALDI-TOF mass spectrometry. The photovoltaic performance of the newly synthesized compound in dye-sensitized solar cells was investigated. In order to clarify the effect of dye-sensitization time on photovoltaic performance parameters, the sensitization time was varied from 12 to 60 h and the performance parameters were investigated. It was found that sensitization time had a strong effect on the main performance parameters. The best photovoltaic performance was achieved after sensitization for 36 h (short circuit current density, 6.41 mA cm−2; overall conversion efficiency, 3.42%). Geometry optimization of the molecule was performed using density functional theory and shows a peripheral structure.


2019 ◽  
Vol 26 (03) ◽  
pp. 1850164 ◽  
Author(s):  
SWATI S. KULKARNI ◽  
S. S. HUSSAINI ◽  
GAJANAN A. BODKHE ◽  
MAHENDRA D. SHIRSAT

Titanium dioxide (TiO[Formula: see text] nanoparticles have been synthesized by the cost effective Sol–Gel technique. Characteristics of TiO2 nanoparticles were investigated by X-ray diffraction and Fourier Transform Infrared spectroscopy. The Eosin Y dye and dye extracted from Hibiscus tea have been successfully used in fabrication of the dye sensitized solar cell. The photovoltaic performance of the dye sensitized solar cell indicates that the short circuit photo current, open circuit voltage and efficiency of the DSSC using Eosin Y dye is 10 times more compared to the DSSC using the Hibiscus dye.


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