DEVELOPMENT OF TITANIUM DIOXIDE PHOTOELECTRODE MATERIAL FOR DYE SOLAR CELL

Dye solar cell (DSC) has advantage over other solar generation; high possibilities for improving parameters, compatible with flexible substrate, lower productions cost and work even in diffuse light. However, DSC still suffers from low efficiency due to the competition between electron generation and recombination. The aim of the study is to develop TiOz photoelectrocle material namely nanoparticles, aggregates and aggregates/nanoparticles composite that promise better performance efficiency of DSC. The effect of two critical parameters; percentage of water in ethanol solution and calcination temperature on the morphology and microstructure of the synthesized TiOz aggregates have been investigated using SEM, XRD and BET. TiOz photoelectrode films were prepared by screen printing technique on FTO glass, dye-coated with N719, and assembled in sandwich configuration with platinized conducting electrode to form DSC. The performance of the integrated DSCs was compared based on UV-Vis absorption and I-V characteristic under simulated AM1.5 sunlight illumination with 100 mW/cm2 light output. Synthesized TiOz nanoparticles photelectrode materials exhibit an efficiency of 3.545%, while aggregates synthesized with 0.9 vol% of water shows higher efficiency of 3.915%. The optimum calcination temperature was found to be at 45o·c. Higher efficiency of over 4% can be achieved by incorporating 20% nanoparticle in aggregates films synthesized using 0.9 vol% of water content and calcined at 45o·c, producing well formed spherical aggregates with mean size of 0.45 11m consisting of 15±3 nm of nanocrystallite. The submicron-sized aggregates can induce the light scattering while nanocrystallites can increase the surface area for dye chemisorption. The incorporated nanoparticles in aggregates films results in better connectivity thus improves the transport properties. The breakthrough in hierarchical structured photoelectrode material could spur the development of higher performance DSC to challenge the high cost of commercially available silicon-based solar cells

DEVELOPMENT OF TITANIUM DIOXIDE PHOTOELECTRODE MATERIAL FOR DYE SOLAR CELL

Dye solar cell (DSC) has advantage over other solar generation; high possibilities for improving parameters, compatible with flexible substrate, lower productions cost and work even in diffuse light. However, DSC still suffers from low efficiency due to the competition between electron generation and recombination. The aim of the study is to develop TiOz photoelectrocle material namely nanoparticles, aggregates and aggregates/nanoparticles composite that promise better performance efficiency of DSC. The effect of two critical parameters; percentage of water in ethanol solution and calcination temperature on the morphology and microstructure of the synthesized TiOz aggregates have been investigated using SEM, XRD and BET. TiOz photoelectrode films were prepared by screen printing technique on FTO glass, dye-coated with N719, and assembled in sandwich configuration with platinized conducting electrode to form DSC. The performance of the integrated DSCs was compared based on UV-Vis absorption and I-V characteristic under simulated AM1.5 sunlight illumination with 100 mW/cm2 light output. Synthesized TiOz nanoparticles photelectrode materials exhibit an efficiency of 3.545%, while aggregates synthesized with 0.9 vol% of water shows higher efficiency of 3.915%. The optimum calcination temperature was found to be at 45o·c. Higher efficiency of over 4% can be achieved by incorporating 20% nanoparticle in aggregates films synthesized using 0.9 vol% of water content and calcined at 45o·c, producing well formed spherical aggregates with mean size of 0.45 11m consisting of 15±3 nm of nanocrystallite. The submicron-sized aggregates can induce the light scattering while nanocrystallites can increase the surface area for dye chemisorption. The incorporated nanoparticles in aggregates films results in better connectivity thus improves the transport properties. The breakthrough in hierarchical structured photoelectrode material could spur the development of higher performance DSC to challenge the high cost of commercially available silicon-based solar cells

The Potential of Waste Cooking Oil B20 Biodiesel Fuel with Lemon Essential Oil Bioadditive: Physicochemical Properties, Molecular Bonding, and Fuel Consumption

This study is motivated by the depletion of fossil fuels in nature, which is inversely proportional to the higher level of fuel oil consumption, so the need for alternative fuels, namely biodiesel. Biodiesel can be made using waste cooking oil because of its abundant quantity, low price, and not being reused. One of the efforts to achieve energy conservation and improve fuel quality is using bioadditives. A lemon essential oil can be used as a bio-additive because it is easily soluble in fuel and its oxygen-rich content can reduce the rate of fuel consumption. The process in this study is to produce biodiesel with waste cooking oil (WCO) using a transesterification process. Biodiesel samples containing the bioadditive lemon essential oil on B20 biodiesel with varying volume fraction (0%; 0.1%; 0.15%; 0.2%). In general, this research can be done in three steps. The first step is the characterization of the compound composition (GCMS) and functional group (FTIR) of diesel fuel, biodiesel, and lemon essential oil bioadditive. The second step is the characterization of the physicochemical properties (density, viscosity, flash point, calorific value) of B20 biodiesel with various concentrations of lemon essential oil bioadditive, then compared with SNI 7182:2015. The third step is determining the rate of fuel consumption in diesel engines. The results show that Biodiesel B20 with a volume fraction of 2% lemon essential oil bioadditive has a high ability to reduce the rate of fuel consumption. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Optimization of Photoelectrode Dye-Sensitized Solar Cell using Composite Zn/F-doped TiO2 Nanoparticles and SiO2-TiO2 Core-Shell Structures

Dye-sensitized solar cell (DSC) is a photoelectrochemical cell that has a similar mechanism as photosynthesis in nature with efficient electron separation, allowing the device to perform well under cloudy condition. However, undesirable recombination reaction of generated electrons with oxidized species has restricted the development of high performing DSC

Enhancement of Charge Transport of a Dye-Sensitized Solar Cell Utilizing TiO2 Quantum Dot Photoelectrode Film

A dye-sensitized solar cell (DSC) is the third generation of solar technology, utilizing TiO2 nanoparticles with sizes of 20–30 nm as the photoelectrode material. The integration of smaller nanoparticles has the advantage of providing a larger surface area, yet the presence of grain boundaries is inevitable, resulting in a higher probability of electron trapping. This study reports on the improvement of charge transport through the integration of quantum dot (QD) TiO2 with a size of less than 10 nm as the dye absorption photoelectrode layer. The QD TiO2 samples were synthesized through sol–gel and reflux methods in a controlled pH solution without surfactants. The synthesized samples were analyzed using microscopic, diffraction, absorption, as well as spectroscopic analyses. A current–voltage and impedance analysis was used to evaluate the performance of a DSC integrated with synthesized TiO2 as the photoelectrode material. The sample with smaller crystallite structures led to a large surface area and exhibited a higher dye absorption capability. Interestingly, a DSC integrated with QD TiO2 showed a higher steady-state electron density and a lower electron recombination rate. The shallow distribution of the trap state led to an improvement of the electron trapping/de-trapping process between the Fermi level and the conduction band of oxide photoelectrode material, hence improving the lifetime of generated electrons and the overall performance of the DSC

Nanoparticle/Core-Shell Composite Structures with Superior Optical and Electrochemical Properties in a Dye-Sensitized Solar Cell

The dynamics of competition between kinetic electron generation and recombination have restricted the development of a higher-performance dye-sensitized solar cells (DSSC). The key to minimizing the competition is optimizing the nanostructures and thickness of the photoelectrode film. It has been reported that the optimum thickness of photoelectrode film to achieve high-performance efficiency is about 12–14 µm. In this study, a photoelectrode film, which is approximately 4 µm thinner compared with those previously reported and has improved performance efficiency, was successfully developed by using composite nanoparticles and core-shell structures. The fabricated DSSC shows an enhanced light scattering, improved dye absorption capability, and reduced electron recombination rate despite the thinner photoelectrode film. The synthesized elongated nanoparticle structure provides a larger surface area for anchoring more dye molecules. In addition, the micron-sized core-shell structures with different refractive indexes of the inner and outer material resulted in multiple refractions and closed-loop light confinement. The successful development of a high-performance thin photoelectrode film will lead to material and cost savings

Modified polyol-mediated synthesis of doped TiO2 nanoparticles as the photoanode in dye solar cells (DSCs)

Synthesis of nanoscale TiO2 exhibiting specific properties of electron or ion conductivity is critical to improve the performance of dye solar cells (DSC). This paper presents the modified polyol-mediated synthesis of doped TiO2 nanoparticles. TiO2 samples were doped with cobalt (Co) and nickel (Ni) and the effects of calcination temperature (550 °C and 650 °C) on the crystallinity of pure samples were investigated. X-ray diffraction (XRD) analysis was used to determine the effect of dopant in lattice structure. The morphology and Crystal structure of TiO2 samples and their chemical analysis was conducted using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectrometer respectively. Results show agglomeration of spherical particles in all doped samples. Crystal structure in the doped samples reveals modified phases and major crystal phase identical to anatase. It is observed that the molar ratio of water to metal can control the nucleation and growth and prevents significant agglomeration of nanoparticles. More effective doping was recorded for samples with 0.5 % concentration. Effective hydroxyl group is detected in both 0.5% Ni and Co promising good photocatalytic material. SEM images of 0.2% Ni-doped sample shows smallest average particle size

Impact of various microalgal-bacterial populations on municipal wastewater bioremediation and its energy feasibility for lipid-based biofuel production

The microalgal-bacterial co-cultivation was adopted as an alternative in making microbial-based biofuel production to be more feasible in considering the economic and environmental prospects. Accordingly, the microalgal-bacterial symbiotic relationship was exploited to enhance the microbial biomass yield, while bioremediating the nitrogen-rich municipal wastewater. An optimized inoculation ratio of microalgae and activated sludge (AS:MA) was predetermined and further optimization was performed in terms of different increment ratios to enhance the bioremediation process. The nitrogen removal was found accelerating with the increase of the increment ratios of inoculated AS:MA, though all the increment ratios had recorded a near complete total nitrogen removal (94–95%). In light of treatment efficiency and lipid production, the increment ratio of 0.5 was hailed as the best microbial population size in accounting the total nitrogen removal efficiency of 94.45%, while not compromising the lipid production of 0.241 g/L. Moreover, the cultures in municipal wastewater had attained higher biomass and lipid productions of 1.42 g/L and 0.242 g/L, respectively, as compared with the synthetic wastewater which were only 1.12 g/L (biomass yield) and 0.175 g/L (lipid yield). This was possibly due to the presence of trace elements which had contributed to the increase of biomass yield; thus, higher lipid attainability from the microalgal-bacterial culture. This synergistic microalgal-bacterial approach had been proven to be effective in treating wastewater, while also producing useful biomass for eventual lipid production with comparable net energy ratio (NER) value of 0.27, obtained from the life-cycle analysis (LCA) studies. Thereby, contributing towards long-term sustainability and possible commercialization of microbial-based biofuel production