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TiO2/SWCNT nanocomposite has been successfully synthesized by the sol-gel method. Single-walled carbon nanotubes (SWCNT) functionalized with acid. TiO2/SWCNT composite was coated on the cork with a dip-coating technique. The crystal structure, morphology, and physicochemical properties of the composites were characterized by FTIR, XRD, SEM-EDX, SEM mapping, and UV-Vis spectra. FTIR data obtained functional groups of TiO2 and carbon. XRD test shows the crystal structure and shape of the nanoparticle material. SEM test was found that TiO2 was firmly attached to the sidewall of the SWCNT. The performance test of TiO2/SWCNT composite was evaluated by monitoring the degradation rate of methylene blue (MB) under a solar simulator. There was a significant decrease in the concentration of methylene blue (MB) when TiO2/SWCNT composite coated on the cork was added. After degradation for 2 hours, the results of the effectiveness of TiO2/SWCNT composite are approximately 99%. The photocatalytic activity of the TiO2/SWCNT nanocomposite in this experiment was influenced by the different compositions of TiO2 and SWCNT, the method used, the success of coating on the cork and light from the solar simulator. [ABSTRACT FROM AUTHOR]

The evolution of energy storage devices that have specific capacitance, high power density, and high energy density is an important for human life. Supercapacitor is a complimentary of replacement a battery that has been extensively developed. The supercapacitor shows the high capacity and power density. The disadvantage of energy density of supercapacitor may be overcome by combining with the advantage of battery in supercapattery. Supercapattery is an ideal type of energy storage because it has a good energy density of batteries and a greater power density of supercapacitors. Cobalt and Zinc are transition metal electrodes that have been widely studied as supercapacitor electrode materials because they have high conductivity and electrochemical activity. Here, Mn2O3 material has high redox and is non-toxic, so it has the potential to be used as electrode material in supercapattery. Initially, the two materials were synthesized into a composite paste which was then deposited on the substrate using the doctor blade method. Furthermore, the electrode M/Mn2O3 (M=Zn, Co) was arranged with a separator and the 1 M Na2SO4 electrolyte to forms a supercapattery. In this work, we have the specific capacitance of 46.95 F·g−1 for supercapattery (Zn/AC/Mn2O3//AC) and 21.83 F·g-1 for (Co/AC/Mn2O3//AC). [ABSTRACT FROM AUTHOR]

Photo-anodes based on TiO2 have been widely used in DSSC devices. However, TiO2 has a high rate of electron recombination, thus limiting the energy conversion of the DSSC. One of the strategies to increase TiO2 capability is to perform surface functionalization with other materials such as carbon. Carbon has a large specific surface area, high electron mobility, excellent optoelectronic and electrocatalytic properties. Activated Carbon (AC) is an allotrope of carbon with the highest surface area, while Black Carbon (BC) has better electrical conductivity. Surface area and electrical conductivity are important parameters to produce high-efficiency DSSC. In this research, the effect of TiO2/C (C=AC and BC) nanocomposites as a photo-anode for DSSC have been investigated. The TiO2/C photo-anode was fabricated by a doctor blade method. It is found that TiO2/C nanocomposite improves efficiency DSSC based on TiO2. The optimum performance was obtained on TiO2/AC photo-anode with an efficiency of 0.475%. [ABSTRACT FROM AUTHOR]

Green energy production for environmental protection and its sustainability has been a hot topic for the last decade. The solar source is one of the candidates for green energy to be developed in Indonesia. It is because of the tropical climate that makes Indonesia receives a lot of sun exposure. Besides, the development of green energy needs to be balanced with the development of better energy storage. The high-power density, long lifetime, and environmentally friendly are exciting and unique points of a supercapacitor. Research of photo-supercapacitor, which integrating solar cells with a supercapacitor, has been developed widely. This Integrated structure will capture and convert light energy into electrical energy then store it. Investigation on improving DSSC performance was carried out in many ways, such as a variation on dye materials, variation on the photoanode material, and other component variation, observations on the effects of temperature variations in the growth of photoanode materials, and investigation on the role of blocking layers and any others. To obtain a good start for the next investigation, we need a complete map of the recent progress on the integrated photo-supercapacitors, mainly the device constructed from EDLC and DSSC. This review article is focused on summarizes current trends in the structure and performance of integrated EDLC Supercapacitor with DSSC. The optimized additional blocking layer in the DSSC section for integrated photo-supercapacitors devices is also proposed. [ABSTRACT FROM AUTHOR]

In this research, we produced Co0.6Fe2.4O4 nanoparticles covered by natural surfactants from Syzygium polyanthum extract. The results of XRD analysis showed that the Co0.6Fe2.4O4 nanoparticles were successfully synthesized, which was indicated by the presence of the spinel phase without other phases. The Co0.6Fe2.4O4 nanoparticles had a particle size of 12.1 nm. SEM image indicated that the morphology of the nanoparticles was spherical and agglomerated with an average particle size value of 34.2 nm. Furthermore, the FTIR spectrum showed the vibrational peaks of C=C and C-H at the wavenumbers of 1633 cm−1 and 2881 cm−1, indicating the presence of the surfactant Syzygium polyanthum. At the wavenumbers of 500₋600 cm−1, the vibrational peaks of Fe-O and Co-O were overlapped, which indicated that the Co2+ ion has succeeded in replacing the position of the Fe3+ ion. Our data analysis results also captured that the Co0.6Fe2.4O4 nanoparticles using natural surfactants from Syzygium polyanthum are potential candidates as high-performance antifungal agents. [ABSTRACT FROM AUTHOR]

Nowadays there's a high demand for Electrochemical Energy Storage which has the high specific capacitance, power density, and energy density. To address this need, supercappteries are being developed that can combine the merits of batteries and supercapacitor into one device as innovative hybrid EES devices. Herein, Mn2O3/GO/AC composite has been synthesized by using a simple procedure for blending and subsequent annealing procedure. This composite was applied as anode material in supercapatteries. With the mass variation Mn2O3 and the scan rate variation, it shown that 20 wt% Mn2O3 at 10 mV/s has the highest spesific capacitance among them, 18.93 F/g, and 2.63 Wh/kg for energy density. [ABSTRACT FROM AUTHOR]

One of the hot materials in thermoelectric is the skutterudite CoSb3 compound, which shows excellent potential as a thermoelectric material because Sb-based skutterudite thermoelectric materials have high mobility, large atomic mass, and high electrical conductivity. The effort of substituting transition metal (Fe) or (Ni) ions at Co site is an attempt to modify the local distortion and increasing electrical conductivity. In this work, we report the synthesis of the skutterudite CoSb3 compound using a modified polyol method. We used CoCl2.6H2O, FeCl3.6H2O, NiCl2, and SbCl3 raw materials as precursors. During the process, we used polyvinylpyrrolidone (PVP) as a stabilizer. The precursors were reduced by NaBH4 in tetraethylene glycol (TEG) at 513 K in a nitrogen atmosphere with 30 minutes for holding times. The yielded products were characterized by XRD, SEM-EDX, FTIR, and electrical conductivity. From the analysis of XRD data, we found that the nanoparticles show grain size between 15 to 32 nm. The nanoparticles were mostly identified as the CoSb3 phase, and the other phase of CoSb2 was also detected. And then, from the analysis of SEM-EDX data, there was agglomeration in the samples so that the particles size become larger and unstable. The chemical bonds of samples actually in the wavenumber range below 500 cm-1. The electrical conductivity increased with increasing stoichiometry fractions of Co1-xFexSb3 (x = 0, 0.05, and 0.1) or Co1-xNixSb3 (x = 0, 0.15, and 0.2) indicating that the samples can be used as a raw material for the thermoelectric device. The values of electrical conductivity for samples lay between 103 to 104 Ω-1cm-1, which also indicates the samples were semiconductors. [ABSTRACT FROM AUTHOR]

The development of thermoelectric device engineering has begun with the exploration and innovation of the use of new materials, defect engineering, doping engineering, and material mixing experiments. In previous studies, modifications have been made to the GO/rGO thermoelectric by doping with atom S but in previous studies have not conducted research on other atomic doping and the influence of doping concentrations. In this study, graphene oxide-based thermoelectric devices were doped by phosphorus and nitrogen atoms and modifications to the width of rxGO in the xGO /rxGO pair to get different areas. xGO materials were synthesized with added ultrasonic wave technique from graphene oxide material, then deposition to polyimide substrates. The fabrication process was done to form PGO/rPGO line modification of 0.5/0.25, 0.5/0.5, 0.5/0.75 mm and NGO/rNGO line modification of 0.75/0.75, 0.75/1.00 mm for using irradiation laser technique with length wave 405 nm and power 1.5 W. The characterizations used are X-Ray Diffraction, SEM, Temperature sensor and I-V. The voltage comparisons result of modification rPGO width line dT=10K were rPGO line width 0.25 mm>0.5 mm>0.75 mm (0.201, 0.165, and 0.126 Volts) Volt, as well as the seebeck coefficients comparison result were rPGO line width 0.25 mm>0.5 mm >0.75 mm (3.33, 2.95, 2.18) x 10−4 V/K. The voltage comparisons result of modification rPGO width line dT=10K were rNGO line width 0.75 mm>1.0 mm (0.47 and 0.4) Volt, as well as the seebeck coefficients comparison result were rNGO line width 0.75 mm>1.0 mm (2.52, 2.47)×10−2 V/K. [ABSTRACT FROM AUTHOR]

Energy storage continues to be a growing research topic. Supercapacitors are a good new choice of energy storage devices because they have good performance with high-density values, relatively fast charging, long-lasting lifetime, and are included in environmentally friendly technologies. The development of materials and structures in an extensive manner continues to be studied. Materials that can support energy storage devices have high capacitance, such as Activated Carbon (AC) and Bismuth Phosphate (BiPO4) as electrode materials. However, the energy density of carbon-based supercapacitors is still low. On the other hand, BiPO4 has good crystallinity and stability, high thermal and chemical properties, and has an ideal redox-active specificity as a supercapacitor electrode material. There is a lot of research on supercapacitor materials that have been released. The article summarizes current trends in the development of supercapacitor material synthesis and supercapacitor performance, particularly AC-BiPO4−based electrodes. The use of BiPO4 phosphate metal materials optimized to improve the performance of the supercapacitor electrode material is also proposed. Several supercapacitor material applications and new developments of supercapacitors and prospect analysis are also presented in this report. [ABSTRACT FROM AUTHOR]

Supercapacitor has received considerable attention as a promising energy storage device due to its fast charging, excellent cyclic stability, and high-power density. Activated carbon is the main material used to make supercapacitor electrodes because it has a high theory-specific surface area reach of 2,685 m2g−1 and low cost. However, structure micropore activated carbon had poor ionic diffusion and transportability that make inefficient surface area utilization, long charge-discharge performance, and low cycle life. Therefore, continuous research is needed to improve supercapacitor performance by adding and modifying structure micropores to increase the performance of electrochemically active sites so that ionic diffusion is better. This research is focused on the influence of concentration PVP immersion 0 M and 0.06 M with the dehydrogenation method. The higher concentration PVP strongly influenced the microstructure, morphology, and electrochemical process. The activated carbon mesoporous was characterized by XRD, SEM – EDX, FTIR, BET, and Charge Discharge. Further, the supercapacitor with the best performance is shown by the highest concentration of PVP 0.06 M exhibited the highest specific capacitance, energy density, and power density of 83.83 F.g−1, 60.06 Wh kg−1, 454.24 Wkg−1. ACM-0.06 had highest cycle stability in the cell voltage of 0-2.4 V at a current density of 0.1 Ag−1, and maximum energy density is 58.96 Wh kg−1 with 95.82 % capacity retention after 25 cycles. [ABSTRACT FROM AUTHOR]

Supercapacitor is able to provide fast charging rate, environmentally friendly and relatively abundant material availability. Manganese dioxide (MnO2) has a high potential to use as a supercapacitor electrode material because of its significant advantages compared to other metal oxides such as high specific capacitance due to the reversible redox reaction and affordable prices. Briefly, the experiment begins with the preparation of a composite solution with a variety of compositions that was deposited on the aluminum foil substrate as electrodes using the doctor blade method. The supercapacitor was packed in a coin cell with 1 M Et4NBF4. The symmetric supercapacitor cycled in the cell potential window of 0-2 V, exhibited excellent specific capacitance of 52.87 F g−1, with power density of 344.94 Wh kg−1 and maximum energy density of 21.84 Wh kg−1 with 82.23 % capacity retention for 100 cycles. [ABSTRACT FROM AUTHOR]

A fuel cell is well known as clean energy that can be categorized as a renewable energy source. Proton Exchange Membrane Fuel Cell (PEMFC) is one kind of fuel cell, which works in low temperatures using a simple structure. Regarding this advantage, PEMFC can be a chance for introducing fuel cell process to students in vocational high school with renewable energy majors. Reaching the goal requires a learning media that can show the structure and process using interactive educational kits. The educational kits are built as trainers, which could be more effective when integrated with smartphone applications. The application can work with multi-platform interactive media, such as augmented reality. Then, the educational kits named Robo-PEM were developed to introduce PEMFC implementation by using Science, Technology, Engineering, and Mathematics (STEM) model. The Robo-PEM consists of a trainer, job sheets, and material course, which are combined in the Robo-PEM application. The Robo-PEM educational kits were evaluated by learning media experts. The result shows that the Robo-PEM educational kits were valid and could be implemented for learning media in vocational high school. [ABSTRACT FROM AUTHOR]

Dye Sensitized, Solar Cell (DSSC) is the most attractive technology in third-generation solar cells due to its simple operation, easy fabrication, great use of raw materials, and ability to be flexible panels. One of the materials that are often used in DSSC is titanium dioxide. Titanium dioxide is a semiconductor material formed from Ti4+ ions and O2- ions. Titania has a stable chemical structure under ultraviolet light. The anatase phase of titania has high photocatalytic activity compared to other phases, so it is widely used for DSSC applications. One of the important components in DSSC is the stability and morphology of the photoanode, so that in this study additional treatment will be carried out on the TiO2 photoanode. The addition of this treatment aims to improve the interconnection of TiO2. One of the materials used as a treatment is TTIP. This treatment is carried out by dip coating. From the experiments, the data shows that the efficiency increased up to 30% after treatment, from 3.78% to 5.45%. This study can explain through the morphology of the SEM characterization results where it is seen that there is a TiO2 layer with a decrease in porosity from 64% to 60% after treatment. In addition, this treatment also shows an increase in the effectiveness of TiO2 charge transfer as indicated by the results of impedance analysis where the RCT of the sample without treatment is 15 ohms and the sample with treatment is 8 ohms. [ABSTRACT FROM AUTHOR]

The design innovation and composition of TiO2 as a photoanode have been continuously studied in recent years to improve the photoconversion performance of Dye-sensitized Solar Cells (DSSC). The important components in the formation of TiO2 paste are solid content, solvents, and organic compounds as binders. In terms of solvents, water or simple alcohol are not suitable for screen printing methods, because cracking will occur after the annealing process by rapid evaporation. In this report, we investigated the addition of nitric acid (HNO3) and ethyl cellulose (CH2CH3) as a binder for optimize the overall DSSC performance. TiO2 photoanode was synthesized by screen printing method through the initial stage of making blocking layer with spin coating method. The effect of nitric acid and ethyl cellulose on, TiO2 powder was studied intensively to determine the best photoconversion performance. TiO2 films were prepared by varying the process without and with post-treatment. The XRD pattern confirmed the presence of a pure anatase phase of TiO2. The morphology of the photoanodes surface area were studied through SEM characterization. The characteristics of J-V shows an increasing in photocurrent and efficiency through the post-treatment process. DSSCs based on TiO2-HNO3 photoanode with post-treatment exhibited a highest efficiency of 3.59%. We found that the sample with post-treatment process have a smaller impedance than sample without post-treatment with charge transfer resistance (RCT) of 10 Ω and 23 Ω, respectively. It may indicate that the TiO2 film with post-treatment have a better interconnection then charge transfer and charge extraction process are more effective and resulting higher efficiency. [ABSTRACT FROM AUTHOR]

One-dimensional (1D) nanostructures are known to contribute a straight pathway for electron transfer to achieve good device performance. Besides that, Titanium dioxide (TiO2) is a metal oxide semiconductor, investigated as a material with upstanding physical and chemical properties with excellent light sensitivity, good relialibility in the environment, and low synthesis costs. In this research, the composite of ZnO nanorod/TiO2 designed to become a semiconductor coating material for photoanodes to support the process of electron transport. In this research, hexagonal structures of ZnO nanorods were synthesized by various growth time of hydrothermal synthesis method. The growth time affects to ZnO nanorods was systematically investigated on ZnO nanorods/TiO2 composites by scanning electron microscopy. From the XRD analysis showed that the ZnO nanorods in a crystalline phase in ZnO nanorods/TiO2 composites. Its crystallinity increases with increasing hydrothermal duration. In addition, the hydrothermal duration of 5 hours resulted the largest diameter and thickness of ZnO nanorod. [ABSTRACT FROM AUTHOR]