TiO2 Paste Research Articles

Dye-Sensitized Solar Cells Characterization of Kitolod Leaves (Hippobroma longifora)

Energy from fossil fuels is decreasing day by day and also causes many environmental problems. In the current era, many environmentally friendly renewable energy sources have been developed, such as the development of DSSC (Dye Sensitized Solar Cells). DSSC is a technology that utilizes colored materials sourced from nature which are used as absorbers of sunlight energy to be converted into electrical energy. In this research, the synthesis and characterization of organic material from kitolod leaves as DSSC will be carried out. Kitolod leaves (Hippobroma longifora) are wild plants that usually grow in home gardens and rice fields. Kitolod leaves which have chlorophyll can support the absorption of sunlight if applied as a sensitizer in DSSC. The methods that will be used in this research are making TiO2 paste, dye solution preparation, electrolyte solution preparation, DSSC fabrication, testing and characterization. The tests that will be carried out are testing the TiO2 layer, dye absorption, and electric current. Meanwhile, the characterization that will be carried out is dye absorption using UV-Vis, and electric current using a potentiometer. From the results of light absorption shows that when the wavelength is 500 nm or the green light spectrum, the maximum light absorption by the chlorophyll of kitolod leaves is 1.78 (a.u.). The maximum voltage (Vm) and maximum current (Im) in daylight lamps have greater values ​​compared to warm white lamps. The highest efficiency of the solar light source is shown when the air mass is 1.5 (08.30-08.40). The time of DSSC immersion in dye also influences the resulting of Vm and Im values ​​which can be shown in that the Vm and Im values ​​of DSSC 2 (30 minutes) are greater than those of DSSC 1 (10 minutes). The results of open circuit voltage (Voc) and the short circuit current (Isc) in this research still need to be improved to produce better efficiency.

Polyvinylidene fluoride‐co‐hexafluoropropylene polymer gel electrolyte‐enabled dye‐sensitized solar cell for sustainable energy

AbstractDeveloped specifically to address leakage and stability concerns inherent in liquid electrolytes, this study presents a significant advancement in polymer gel electrolyte (PGE) formulation by combining potassium iodide (KI), ammonium iodide (AI) salts, and polyvinylidene fluoride‐co‐hexafluoropropylene (PVDF‐co‐HFP) as a host polymer. The tape casting method was employed to deposit the standard TiO2 paste as the photoanode and platinum paste as the counter electrode. N3 dye was incorporated, and PVDF‐co‐HFP was used as the PGE between the electrodes. The conductivity of PGE was measured by using a digitized conductivity meter. The quasi solid‐state solar cell (QS‐DSSC) assembled using single salts (KI, and AI), and mixed cations PGE was examined via photocurrent–voltage characteristics, and electrochemical impedance spectroscopy. The augmented ionic conductivity directly influences the efficiency of DSSCs. Notably, incorporating a mixed salt (KI + AI) within the PGE enhances ionic conductivity compared to single‐salt‐based counterparts. The resultant DSSCs using mixed salt PGE exhibit a Voc of 600 mV, Jsc of 1.01 mA/cm2, FF of 0.6089, and an efficiency of 0.369%, outperforming those using KI or AI. This highlights the perceptible advantages of employing this innovative electrolyte composition to enhance solar cell performance.

Novel 2D heterostructure composites of V2C MXene/TiO2 and graphene/TiO2 for platinum replacement in dye-sensitized solar cells

This study evaluates the potential of V2C MXene/TiO2 and Graphene/TiO2 composites as alternatives to platinum for counter-electrodes in dye-sensitized solar cells (DSSCs). V2C MXene was synthesized by selectively etching the aluminum layer from V2AlC MAX phase powder, resulting in multilayered V2C MXene. The layered morphologies of MXene and graphene were confirmed via Scanning Electron Microscopy (SEM), while their crystalline structures were validated using X-ray diffraction (XRD) analysis. SEM analysis confirmed the delaminated layered structure of graphene and the distinct layers of V2C MXene. XRD findings showed that MXene has significantly greater interlayer spacing than graphene, offering more catalytic sites for charge injection. Electrocatalysts were prepared by incorporating TiO2 paste with MXene and graphene, with TiO2 serving as a binder. These composites were then employed as counter-electrode materials in dye-sensitized solar cells. The MXene-based counter electrode achieved a photoconversion efficiency of 1.625 %, surpassing graphene-based (1.149 %) and Pt-based (1.567 %) counterparts under standard illumination. The efficiency of cells was meticulously characterized over an extended period. The results indicated that the efficiency of these cells remained stable over time. This stability suggests that MXene/TiO2 and Graphene/TiO2 based catalysts are robust and do not degrade with time.

Sol-Gel Synthesis of TiO2 with Pectin and Their Efficiency in Solar Cells Sensitized by Quantum Dots.

In this study, titanium oxide TiO2 nanoparticles were produced using the sol-gel approach of green synthesis with pectin as the reducing agent. The synthetized TiO2 nanoparticles with pectin were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), visible light absorption (UV-Vis) and the BET method. The structure and morphology of the TiO2 powder were described with SEM, revealing uniform monodisperse grains with a distribution of 80% regarding sizes < 250 nm; the resulting crystal phase of synthetized TiO2 was identified as an anatase and rutile phase with a crystallinity size estimated between 27 and 40 nm. Also, the surface area was determined by nitrogen adsorption-desorption using the Brown-Emmet-Teller method, with a surface area calculated as 19.56 m2/g, typical of an IV type isotherm, indicating mesoporous NPs. UV-Vis spectra showed that sol-gel synthesis reduced the band gap from the 3.2 eV common value to 2.22 eV after estimating the optical band gap energy using the adsorption coefficient; this translates to a possible extended photo response to the visible region, improving photoactivity. In addition, the power conversion of the photoelectrode was compared based on similar assembly techniques of TiO2 electrode deposition. Quantum dot crystals were deposited ionically on the electrode surface, as two different paste formulations based on a pectin emulsifier were studied for layer deposition. The results confirm that the TiO2 paste with TiO2-synthesized powder maintained good connections between the nanocrystalline mesoporous grains and the deposited layers, with an efficiency of 1.23% with the transparent paste and 2.27% with the opaque paste. These results suggest that pectin could be used as a low-cost, functional sol-gel catalysis agent for the synthesis of controlled NPs of metal oxide. It demonstrates interesting optical properties, such as an increase in photo response, suggesting further applications to photocatalysts and biomedical features.

Fabrication of binder-free TiO2 P 25 films on flexible PET/ITO substrate for photoanode in dye-sensitized solar cells

In this work, TiO2 P 25 films for photoanode in dye-sensitized solar cells (DSSCs) have been fabricated using a flexible PET/ITO substrate with a low-temperature heating technique. Ammonium hydroxide/ethanol solution was used as an alternative binding agent to fabricate TiO2 paste, which can be removed at low-temperature heating. The conventional screen print method is still used in DSSC fabrication because it is a very cheap and easy technique. A hot-pressing method is also used to improve the quality of TiO2 films and the performance of DSSCs. The encapsulation technique used in the assembly of DSSC is expected to increase the stability of DSSC devices to prevent electrolyte leakage. The resulting TiO2 film shows the highest DSSC performance using the hot-pressing and encapsulation method with PCE 0.29%. The encapsulation technique increased the stability of DSSC devices with more extended durability than without encapsulation.

Implementing a Two‐in‐One Defect Passivation Strategy Utilizing CsX for High‐Performance Printable Carbon‐Based Perovskite Solar Cells

AbstractIn the rapidly advancing realm of perovskite solar cells, the rectification of defects has surfaced as a crucial scientific challenge. The control over defect states, especially in printable mesoscopic perovskite solar cells (p‐MPSCs), is hindered by the complexities of screen‐printing technology. Here a novel “two‐in‐one” defect passivation strategy is presented, through doping TiO2 paste with cesium halide salts (CsX, where X = F, Cl, Br, I) to integrate all‐inorganic Cs halides, particularly CsF, into the electron transport layer in p‐MPSCs. Owing to the robust interaction between F− ions and TiO2 compared to Cs+ ions, and the inability of F− to infiltrate the perovskite lattice, F− and Cs+ play distinct roles starting from the buried interface of the p‐MPSCs. Specifically, F− can rectify the oxygen vacancies on the TiO2 surface, thus alleviating the residual stress at the perovskite's buried interface. Simultaneously, Cs+ diffuses to the top perovskite and mends the methylamine vacancies. As a result, the PCE of the optimal device, based on F‐doped TiO2, witnesses a significant improvement from 16.18% (control) to 18.24%. The two‐in‐one strategy utilizing CsX from the buried interface can well realize the all‐inorganic defect rectification, thereby offering a promising prospect for the enhancement of p‐MPSC performance.

Study of the Optical and Structural Properties of Metal-Doped Titanium Dioxide Electrode Prepared by the Sol-Gel Method for Dye-Sensitized Solar Cells

This study presents a strategy to increase the efficiency of dye-sensitized solar cells (DSSCs) by doping titanium dioxide (TiO2) with different magnesium (Mn) concentrations (1, 3, 5, 7, and 9%) generated by the sol-gel process and effectively employed as a photo-anode (the working electrode) for DSSCs. The Doctor Blade method coated the indium-doped tin oxide (ITO) glass with a thin film layer. X-ray diffraction (XRD) was used to evaluate the characteristics of undoped and manganese-doped TiO2, and the results demonstrate that all of the thin films are anatase. The samples were examined using XRD to assess grain size before and after Mn doping. The spectrum of UV-Vis absorption changes; accordingly, as doping increases, the energy gap decreases. The smallest energy gap's value (2.4 eV) is 7% manganese doping. AFM pictures show the average roughness and root mean square of the weight percentage of films doped with 5%. Field effect scanning electron microscope (FE-SEM) studies show that the particle size of thin films gets smaller as more Mn is added, which happens at least as much as 7% Mn doping. The optimal thickness for TiO2 paste over conductive glass is 15 μm, and the cell's power conversion efficiency increased to 0.604074% with an Imax of 4.965 mA, a Vmax of 0.488 V, and a fill factor (FF) of 68.45954%.

A study on using a binder-free TiO2 paste with sodium dodecylbenzene sulfonate addition to improve the performance of low-temperature DSSCs

The utilization of binder-free TiO2 paste allows for the dye-sensitized solar cells (DSSCs) TiO2 electrode fabrication at low temperatures, thus making it a potential material for flexible solar cell devices. However, the physical robustness of formed electrodes using TiO2 paste at low temperatures remains challenging, including issues such as cracking due to film stress and challenges in adjusting the viscosity of the TiO2 paste. In this study, we enhanced the binder-free TiO2 paste performance by incorporating sodium dodecylbenzene sulfonate (SDBS) as an additive for TiO2 electrode precursor solution. It demonstrated that SDBS additives help to relieve internal stress and ultimately enhance the physical and structural characteristics of the films by improving the viscosity in the TiO2 paste and promoting the dispersed pinholes within the TiO2 films. Furthermore, implementing TiO2 paste with varying ratios of SDBS has enabled the fabrication of DSSCs with the highest achieved power conversion efficiency (PCE) of 4.53%, representing an enhancement of nearly 15% compared to TiO2 paste without SDBS. This research presents a practical and effective approach for preparing highly efficient binder-free TiO2 paste.

Synthesis of TiO2 by hydrothermal method using deep eutectic solvent for application in dye-sensitised solar cell

Raw TiO2 powder from a commercial source was used as a precursor in the hydrothermal process with deep eutectic solvent (DES) of choline chloride and urea with a molar ratio of 1:2 at different temperatures and interval times. The synthesised TiO2 was further utilised to produce diffracting TiO2 paste for application in dye-sensitised solar cells (DSCs) to improve the power conversation efficiency of devices. The TiO2 product analysed by X-ray diffraction (XRD) showed a similar phase and crystallinity to the raw material. However, scanning electron microscope (SEM) images showed that the hydrothermal TiO2 product had less particle aggregation than the raw one. The particle size was exceedingly 100 nm. The TiO2 pastes were prepared with a mixture of ethyl acetate and terpineol at volume ratios of 3:7 and 4:6. The paste was suitable to make thin films by the screen-printing method as a diffusion layer in cells. DSC devices using the TiO2 produced by the hydrothermal process with DES at 140oC for 18, 24, and 36 hours, respectively, enhanced the power conversion efficiency by 6.7-6.9%, which was higher than the ones using raw TiO2 by about 7%. Therefore, TiO2 powder modified by the hydrothermal process in DES solvent has great potential for application in DSC manufacture.

Enhanced Indoor Conversion Efficiency of Dye-Sensitized Solar Cells by Optimizing Ball-Milling Process of TiO2 Paste

The rapid spread of the Internet of Things (IoT) along with the development of innovative low-power electronic devices has also driven the development of indoor photovoltaics. In this paper, we propose a simple and economically feasible solution that can improve the efficiency of dye-sensitized solar cells (DSSCs) under indoor light conditions by ~112%, without requiring a complex TiO2 photoanode architecture or the design of new dyes. The ball milling process of the TiO2 paste was optimized for indoor light conditions for the first time, both in terms of efficiency and production costs, by developing a rapid preparation method that can be used industrially for the application of DSSCs. A simple use of 12 mm diameter balls caused beneficial structural modifications, decreasing the size of the crystallites, and leading to a high OH generation on the TiO2 surface responsible for the improvement of energy conversion efficiency.

Fabrication of TiO2-Ag composites for working electrode of dye-sensitized solar cells

A solar cell is a device that can convert solar energy into electrical energy. The third generation of solar cells is Dye-Sensitized Solar Cells (DSSC). Typically, DSSC consists of a working electrode (semiconductive metal oxide), a photosensitizer, an electrolyte, and a counter electrode (platinum or carbon electrode). Among the components, a working electrode is one of the crucial components to control the electrochemical performance. This study examines variations in Ag composition in TiO2-Ag composites against efficiency using two materials and fabrication methods. First, using the solid-state method, TiO2-Ag composites were fabricated from Ag paste and TiO2 paste. The highest efficiency results were achieved at TiO2 N-RT + Ag 1%. The efficiency increased from 1.05% to 1.51% compared to TiO2 without Ag doping. Second, using the solvothermal method, TiO2-Ag composites were fabricated from AgNO3 and TiO2 particles. The highest efficiency results were obtained at TiO2 NP + Ag 0.75%. The efficiency increased from 0.82% to 1.07% compared to TiO2 without Ag doping. Furthermore, the material with the best efficiency was characterized using FTIR, XRD, and SEM to identify the material’s functional groups, phases, and morphology, respectively.

Analysis of Photocatalytic Properties of Titanium Dioxide Electrode Supported By Hydroxyapatite Co-Catalyst in a Marine Solar Cell

Titanium dioxide (TiO2), as an n-type semiconductor photocatalyst, has been widely studied and used in many environmental and energy applications such as solar cells, wastewater treatment, air purification, water splitting for hydrogen production and CO2 conversion due to its superior electrical and optical properties, stability, and biocompatibility. Using its photocatalytic and other properties, we have been studying a floating photoelectrochemical cell that can be applicable to the marine environments. This cell is designed to utilize titanium dioxide as its photoanode and copper oxides photocathode, and seawater is used as an electrolyte between electrodes. The drawbacks of using titanium dioxide as photocatalysts are its high electron-holes recombination rates and lower absorption efficiency in visible light regions. To improve against these drawbacks, we studied hydroxyapatite (HAp, Ca10(PO4)6(OH)2) as co-catalyst for titanium dioxide electrode. Since HAp possesses biocompatibility, it is suitable to be used with TiO2 electrode in marine environments. In previous studies, it was found that HAp improved and boosted the current density produced by the titanium dioxide electrode. However, removal of HAp occurred from the surface of titanium dioxide during the photoelectrochemical measurements. Therefore, in this study, we have optimized the content of HAp paste that would be applied to the surface of titanium dioxide electrode by screen printing method.For preparation of titanium dioxide electrode, type 329J4L stainless steel was selected as the base substrate. Firstly, surface of the substrate was grinded to form the grid pattern and cleaned with ethanol in ultrasonic cleaner and then with distilled water. After that, the substrate was passivated with 10 % HNO3 at 60 ºC for 30 minutes. The passivated substrate was then printed and heat treated with TiO2 paste twice at 150 ºC for 1 hour and 550 ºC for 30 minutes respectively. Double layered titanium dioxide electrode was then printed with HAp paste and heat treated at 150 ºC for 1 hour. To check the characteristics of photocatalytic effect of electrode, photopotential and potentiodynamic polarization measurements were performed to the electrode. For illumination test, xenon light with an intensity of 10.5 mW/cm2 and a calibrated wavelength of 250-800 nm was used as the light source. The measurement was conducted in artificial seawater as the controlled electrolyte. Standard calomel electrode (SCE) was used as a reference electrode and platinum electrode as a counter electrode. The measurement was performed both with and without irradiated conditions. The microstructures and surface morphology of electrode before and after electrochemical measurements were analyzed and examined by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction analysis (XRD).The results show optimized HAp also improve the photocatalytic activities of n-type semiconductor titanium dioxide. In previous study, removal of HAp was considered due to the addition of carboxymethyl cellulose (CMC) as a viscosity modifier to HAp paste. CMC possess higher hydration rate which may cause rapid agglomeration when it is introduced to water. Although it has satisfactory quality to control the viscosity of the paste, rapid hydration cause removal of HAp after the electrode was heat treated and measurement was performed in artificial seawater. In this study, polyethylene glycol (PEG) was used as the viscosity modifier for HAp paste and Triton-X-100 was used as the surfactant to control the surface tension of the paste. As a result, HAp paste was produced to be screen-printable onto the surface of TiO2 electrode and removal of HAp was minimized compared to the previous study. Moreover, HAp became a good sorbent and co-catalyst for titanium dioxide electrode in its photocatalytic activities.

Room-Temperature Processable TiO2 Solar Paint for Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) have emerged as promising alternatives to traditional silicon photovoltaics owing to their environmentally friendly nature, easy preparation, and low cost. However, a critical bottleneck in DSSC fabrication lies in the high-temperature treatment required for the metal-oxide, primarily titanium dioxide (TiO2), photoanode. This study presents an advanced approach aimed at overcoming this challenge by developing a facile and cost-effective room temperature processable TiO2 paste for large-scale device production and commercialization. In our investigation, TiO2 nanoparticles were synthesized using the sol-gel hydrothermal method. The resulting material served as the basis for a solar paint formulation, utilized as a precursor for the photoanode in tertiary butyl alcohol. Applying this paint, achieved with a simple paintbrush, eliminated the need for high-temperature curing, binders, and reduced chemical additives. This minimizes energy consumption during fabrication and enhances the interface quality and charge transport properties of the photoanode, as evidenced by photovoltaic impedance spectroscopy measurements.

Graphite Coupled with TiO2 Paste Photoelectrodes Well Oriented over COD Photoelectrocatalysis for Rapid Detection of Methylene Blue Organic Dye

Graphite Coupled with TiO2 Paste Photoelectrodes Well Oriented over COD Photoelectrocatalysis for Rapid Detection of Methylene Blue Organic Dye

Synthesis of Mg-doped TiO2 Using a Hydrothermal Method as Photoanode on Bixin-Sensitized Solar Cell

Titanium dioxide (TiO2) with magnesium (Mg) doping for dye-sensitized solar cell (DSSC) photoanode application has been synthesized. DSSC components used in this study were photosensitizer (bixin), electrolyte (), cathode (platinum), and photoanode (Mg-TiO2). This research aims to determine the characteristics of Mg-doped TiO2 photoanode with variations in dopant concentration based on the results of XRD and DR/UV-Vis analysis, as well as to determine the maximum efficiency conversion energy of DSSC using Mg-doped TiO2 and undoped TiO2 as photoanodes. The synthesis of TiO2 and Mg-TiO2 was carried out using the hydrothermal method with variations in the concentration of Mg dopant of 0, 0.5, 1, and 2% based on the molar ratio. The presenceof 2% of Mg in anatase TiO2 paste decreased the TiO2 band gap from 3.15 to 2.60 eV. Analysis results show that adding Mg dopant decreased the crystal size. Mg dopants on TiO2 could also form new energy levels, which reduced the band gap energy of TiO2. In addition, the increased concentration of Mg dopants also shifted the absorption capacity of TiO2 from the ultra-violet (UV) wavelengths region to the visible light area. The maximum energy conversion efficiency of the DSSCs with Mg-doped TiO2 photoanode of 0.5, 1, and 2% are 0.045; 0.070, and 0.172%, respectively, where these three efficiency values are higher than undoped TiO2 (0.017%). The results proved that the presence of Mg dopants on the TiO2 photoanode can increase the efficiency of DSSC.

Formation of nanostructured films of titanium dioxide for solar cells sensitized with Roselle flower pigment

In this paper, the study is focused on the assembly and analysis of nanostructured films of titanium dioxide (TiO2) for solar cells sensitized by dyes. An important application of nanostructured films is saved the most among dye because is responsible for absorbing photons. For this reason, the fabrication method of porous TiO2 films is crucial to get a good efficiency of dye-sensitized solar cells (DSSC). The preparation of TiO2 pastes was made by mixing the nanometric and submicron particles of TiO2 with PEG as a plasticizer, α-terpineol, water, and acetic acid to avoid the creation of defects in the films. The screen-printing method was used to build thin films.The analyses of the film were accomplished by employing techniques such as SEM, UV–vis, and adherence, while we used the Van der Pauw method to determine the resistivity of the TiO2 porous film. In conclusion, the ratio PEG/ TiO2 is important for the increase of porosity, so the higher the ratio PEG/ TiO2 higher the porosity thanks to the volume left by the PEG behind the calcination of the films. Three-layer films were obtained by screen-printing with good stability and a thickness of 60 μm.

Exploration of mechanical performance, porous structure, and self-cleaning behavior for hydrothermally cured sustainable cementitious composites containing de-aluminated metakaolin waste and TiO2 nanoparticles

The main goal behind this research is to produce antimicrobial cementitious composites with acceptable mechanical characteristics based on de-aluminated metakaolin waste (DAK) and commercial titania. Two cementitious blends have been prepared: OPC containing 50%DAK and OPC containing 45%DAK +5% TiO2 NPs. Regarding curing time and cost, these blends were treated under two different curing regimes: normal curing under tap water for up to 28-days at room temperature and hydrothermal curing at various steam pressures of up to 12 bars. Compared with the reference paste (OPC/28days), compressive strength test, phases identification, morphology, textural characteristics, and microbial resistivity test were conducted. It was found that the normal cured cementitious composite containing titania NPs possessed the highest strength (88 MPa) compared with reference (80 MPa) and OPC+50%DAK (58 MPa). On the other hand, the strength value for cementitious composite modified with TiO2 NPs reached 96 MPa under autoclave curing at 4 bars for 8 h and became 61.6 MPa for OPC+50%DAK. XRD and TGA/DTG techniques confirmed the formation of binding hydrates (C-S-Hs, C-A-S-Hs and C-A-Hs) under different curing conditions. SEM/EDX indicated stacked plates, fibers, and rods of C-S-Hs under hydrothermal treatment. N2-adsorption/desorption technique revealed that autoclaving conditions significantly reduced the pore diameter of the prepared blends. Two fungi strains (Mucor-circinelloide and Aspergillus-terreus) and two bacteria strains (Gram Positive-Bacillus subtilis-ATCC6633, Gram negative-K. pneumonia-ATCC13883) were used to conduct a self-cleaning test. According to the agar diffusion test, high inhibition zones were observed for normally cured OPC-50%DAK and OPC-45%DAK-5%TiO2 pastes.

Production and Performance of Dye Sensitive Solar Cells Using Co+2 Doped Photo-Anodes

In order to increase the use of solar energy, which is one of the renewable energy sources, it isto produce high-efficiency, low-cost and environmentally friendly dye-sensitive solar cells from solar cellsprovided by photovoltaic technology that generates electricity from solar energy. Therefore, there is a needto develop new materials and modified designs to produce solar cells at lower cost. One way to increasethe efficiency of dye-sensitized solar cells (DSCC) is by doping at the anode. At the same time, graphenepaste was used instead of Pt cathode to reduce the cost. In this study, pure and Cobalt (Co+2) added TiO2pastes were prepared to produce DSCC. Photovoltaic performances were determined by comparing pureand doped batteries with each other. For this purpose, pure and Co+2 added TiO2 pastes were first prepared.The resulting pastes were applied to FTO glasses with the doctor-blade method. Then, DSCCs wereproduced by sandwiching pure and Co+2 doped TiO2 photoanodes sensitized with N-719 dye with graphenecoated FTO thin films. The performance of the produced DSCCs was determined by Current Density (J) -Voltage (V) analysis. There was a certain increase in FF and Jsc values with doping. However, the resultsshowed that the efficiency value of Co+2 doped batteries is 370% above the value of batteries using pureTiO2 photo-anodes.

Property Modulation of Graphene Oxide Incorporated with TiO2 for Dye-Sensitized Solar Cells.

Graphene oxide (GO) nano-powder is synthesized by the modified Hummer's method, and further thin films are deposited by using the water solution of GO through spin-coating. These films are thermally reduced along with the synthesized GO nano-powder at 50 to 200 °C in a high vacuum. Microstructural, electrical, and optical properties are expectedly controlled by thermal reduction. The electronic properties of GO are investigated by X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure. The reduction is confirmed by Raman spectroscopy. The work function and band gap of GO are tuned with the thermal reduction. The changes in properties of GO are not linear, and anomalous changes are observed for the reduction around 150 °C. Pristine and reduced GO nano-powder is incorporated into TiO2 paste to be the photoanode for dye-sensitized solar cells (DSSCs). It is observed that the performance of the fabricated cells is significantly enhanced for the GO reduced at 150 °C, and the cell exhibited a significant increment of ∼23% for the power conversion efficiency in comparison to DSSC based on an unmodified TiO2 photoanode.

Effect of Photosynthetic Pigment Composition of Tropical Marine Microalgae from Ambon Bay Navicula sp. TAD on Dye-Sensitized Solar Cell Efficiency

Solar cells using dyes as sensitizers continue to expand. The synthetic dye used as a sensitizing material for solar cells has high production costs, difficult to find, and can cause environmental pollution. Photosynthetic pigments as sensitizers are considered to be the solution to this matter. In this research, we investigated the effect of photosynthetic pigments from the Navicula sp. TAD as a dye-sensitized material on the efficiency of Dye-Sensitized Solar Cell. To obtain high biomass, the Navicula sp. TAD was cultivated in a modified medium. Pigment extract from dry biomass using acetone, then continued with purification of the pigment using column chromatography techniques. Characterization of pigment by scanning the absorption pattern of visible rays, the fabrication of solar cells with TiO2 paste, and the photographic test of the solar cells filled with solar simulators. Navicula sp. TAD has photosynthetic pigments consisting of chlorophyll and carotenoid with 8.570 gmL−1 and 2.581 gmL−1, respectively. Solar cells using pigment crude extract, chlorophyll, and xanthophyll which TiO2 absorbs as electrodes, have efficiency values of 6.150×10−4, 3.482×10−3, and 4.117×10−3%, respectively.