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"Saat ini banyak dikembangkan energi terbarukan sebagai sumber energi alternatif. Salah satunya adalah dye-sensitized solar cells (DSSC) yang telah menarik perhatian yang cukup besar dalam beberapa tahun terakhir. Telah banyak penelitian yang dilakukan untuk memperbaiki kinerja DSSC salah satunya adalah penelitian mengenai berbagai macam dyes yang dapat digunakan pada DSSC. Dalam sistem DSSC, fenomena hole percolation yang merupakan rekombinasi elektron yang tereksitasi dari dyes dan elektron yang terinjeksi ke TiO2, menjadi perhatian penting karena akan mempengaruhi efisiensi konversi cahaya menjadi listrik. Selain itu adalah degradasi dyes dimana dyes membentuk kationnya untuk kemudian diregenerasi kembali oleh elektrolit. Dalam penelitian ini dipelajari karakteristik dye rhodamine B (RhB) secara spektroelektrokimia. Sebagai elektroda kerja digunakan transparent conductive oxides (TCO) dari kaca yang dilapisi SnO2-F, kemudian dilapisi kembali dengan TiO2-Nanotube (TiO2-NT).TiO2-NT disiapkan dengan teknik rapid breakdown anodization (RBA). Sistem yang dibangun dapat mengevaluasi RhB seperti perilakunya dalam DSSC. Dari hasil studi diketahui bahwa RhB akan menghasilkan konversi cahaya yang baik, terlihat dari nilai koefisien hole percolation yang tergolong kecil (0,0303 x 10-8 sampai 1,7983 x 10-8 cm2/s). Dari hasil penelitian tampak bahwa RhB mudah terdegradasi, dimana nilai kdegradation lebih besar dibandingkan dengan kformasi, yang berakibat pada life time yang pendek. Sistem spektroelektrokimia yang dibangun dapat digunakan sebagai alat untuk mempelajari potensial dyes yang lain dalam sistem DSSC.

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Many renewable energy as an alternative energy source have been developed. One of them is the dye-sensitized solar cells (DSSC) which has attracted considerable attention in recent years. There have been many studies conducted to improve the performance of DSSC, including the study of a wide variety of dyes that can be used in DSSC. A crucial point in the DSSC system is a hole percolation issue, that is recombination of excited and injected electron to TiO2, hence efficiency of light conversion, and degradation issue of the dyes, due to slow electron regaining of temporary formed dyes cation from respective electrolyte. In this research, we studied the characteristics of rhodamine B dyes (RhB) with self built spectroelectrochemical system. The self built spectroelecrochemistry is comprise of self prepared conductive glass (a glass coated by SnO-F), covered by TiO2-Nanotutube (TiO2-NT.The TiO2-NT was prepared by rapid breakdown anodization (RBA) technique. The self constructed spectroelectrochemical system has been successfully being applied to study RhB dyes in a DSSC manner. It is clear that, from this study, the RhB dyes will provide a good light to electricity conversion, as it has a low hole percolation small (0.0303 x 10-8 to 1.7983 x 10-8 cm2/s). Unfortunately the RhB shows susceptible to degradation, where the kdegradation values greater than its kformation value, resulting in short life time. The self constructed spectro-electrochemical system may be applied to study other candidate dyes, as a tool to evaluate their potential as dyes in a DSSC system."

"Pengujian degradasi Rhodamin B dalam sistem Quantum Dot CdS Sensitized Solar Cells QD-CdS-SSC Termodifikasi yang memiliki dua bagian yaitu, zona solar cell dan zona katalisis. Pada zona solar cell, telah berhasil disintesis TiO2 nanotube TiO2 NT band gap 3,2 eV dengan metode anodisasi dan TiO2 nanotube termodifikasi CdS nanopartikel menjadi CdS-TiO2 NT band gap 2,2 eV dengan metode SILAR successive ionic layer adsorption and reaction sehingga aktif pada daerah sinar tampak yang digunakan sebagai sensitizer. Reaksi degradasi Rhodamin B terjadi pada zona katalisis dari perpanjangan plat titanium Ti pada zona solar cell, dengan Pt-Ti sebagai katoda dan N-doped-TiO2 NT sebagai fotoanoda yang disintesis dengan metode anodisasi dari sumber dopan urea. N-doped-TiO2 NT yang dihasilkan memiliki band gap yang lebih rendah daripada TiO2 NT, yaitu sebesar 2,9 eV dan dapat digunakan pada daerah sinar tampak. Karakterisasi terhadap TiO2 NT, N-doped-TiO2 NT dan CdS-TiO2 NT meliputi Scanning Electron Microscope SEM , UV-VIS Diffuse Reflectance Spectrometry DRS , X-ray Diffraction XRD dan Fourier Transform Infra Red FTIR.

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Study on degradation of Rhodamine B in a Quantum Dot CdS Sensitized Solar Cells QD CdS SSC Modified System which has two parts, namely, solar cell zone and cataytic zone. In the solar cell zone, has successfully synthesized TiO2 nanotubes TiO2 NT a band gap of 3.2 eV using anodizing methods and TiO2 nanotubes modified CdS nanoparticles as CdS TiO2 NT band gap of 2.2 eV using SILAR method successive ionic layer adsorption and reaction that is active in visible light region and is used as a sensitizer. The degradation reaction of Rhodamine B occurs in the catalystic zone of extension of the titanium plate Ti from solar cell zone, the Pt Ti as cathode and N doped TiO2 NT as fotoanoda was synthesized by anodizing method of urea as dopant source. N doped TiO2 NT has a lower band gap than TiO2 NT, which amounted to 2.9 eV and can be used in the visible light region. Characterization of TiO2 NT, N doped TiO2 NT and CdS TiO2 NT include Scanning Electron Microscope SEM , UV VIS Diffuse Reflectance Spectrometry DRS , X ray Diffraction XRD and Fourier Transform Infra Red FTIR."

"Solar cells are excellent devices which enable the provision of renewable energy in a safe and easy way. A dye sensitized solar cell (also referred as dye solar cell) is a new type of solar cell, whose operation is based on photoelectronic chemically activated mechanism. The fabrication of dye sensitized solar cells is generally simpler and cheaper compared to the conventional silicon-based solar cells. This paper aims to fabricate and analyze the performance of dye solar cell by comparing the utilization of transparent and opaque TiO2 pastes for the photoelectrodes. In addition, we also perform an analysis on the use of two different red ruthenium based dye, i.e. N-719 and Z-907. The current-voltage (I-V) measurements were performed by using an artificial sun-simulator on AM1.5 irradiation. As for the counter-electrode, platinum (Pt) was used as the catalyst which was deposited using DC-sputtering technique. Our results revealed that the cells featuring transparent TiO2 paste achieved better photoconversion efficiencies compared to that of the opaque paste. The best average efficiency achieved was 3.78% for cells with a total active area of 2 cm2 . In addition, transparent cells produced on average up to 3 mA higher photocurrent compared to that of the opaque cells. We suspected that such behavior was affected by the discrepancy in the crystallite size."

"Different morphologies of zinc oxide (ZnO) can be obtained through various synthesizing methods, such as that of the water bath. By synthesizing under various conditions, different ZnO morphologies can be seen as the result of the water bath method. Replacing ZnO nanoparticles with vertically aligned ZnO nanorods results in a much higher energy conversion efficiency. Yet vertically aligned nanorods can only be grown through difficult and expensive methods. Several researchers have studied the growth of one-dimensional (1D) nanorods on homogeneous film with various growth conditions. However, there has been little in the way of research on ZnO nanorods grown on ZnO seed layers using the water bath method. In this research, vertically aligned nanorods with an optimum size ratio were formed through a simple water bath method. This method reveals that the ZnO nanorods are well aligned and grown with a high density and uniformity on the substrate. Their X-ray diffraction patterns reveal that the nanorods are grow in the [001] direction. The density, diameter, and length of the ZnO nanorods can be altered by changing the growing condition. All of the samples were characterized using a scanning electron microscope, X-ray diffraction, and micro Raman spectroscopy. To investigate crystal growth, zinc nitrate and zinc acetate were used when preparing the solution. The results demonstrate that the morphology and alignment of ZnO nanorods are determined by the precursor’s type and deposition time."

"Faced with ever-shrinking reserves of fossil-based energy, in addition to the damaging impacts of the use of fossil-based energy sources, such as the greenhouse effect and global warming, efforts are needed to find energy alternatives. Currently under development as an alternative source of renewable energy, utilizing solar energy as its source, is a device incorporating the dye-sensitized solar cell (DSSC), which works using the simple photosynthetic-electrochemical principle at the molecular level. In this type of device, inorganic oxide semiconductors such as titanium dioxide (TiO2) offer great potential for the absorption of photon energy from the solar energy source, especially in the form of a TiO2 nanoparticle structure. In this study, a commercial TiO2 nanoparticle was used. The as-received TiO2 nanoparticle was characterized using X-ray diffraction (XRD) and a scanning electron microscope (SEM). For sensitizer, a natural dye extracted from mangosteen (Garcinia mangostana L.) pericarps was used. The extracted natural dye was characterized using Fourier transform infrared (FTIR) for the functional groups, whereas ultraviolet-visible (UV-Vis) was used to examine the absorption activity of the extracted natural dye. Performance of the DSSC was analyzed through a precision current versus potential difference (I-V) curve analyzer. The maximum power conversion efficiency (PCE) of the mangosteen natural dye was obtained using ethanol containing 20% distilled water as compared to commercial organic dye with a PCE of 4.02%. This result is convincing and promising for the next development."

"Amonia merupakan senyawa penting bagi kehidupan di bumi, diantaranya yaitu dalam bidang industri dan pertanian. Permintaan amonia diperkirakan akan meningkat setiap tahunnya. Secara konvensional, fiksasi industri dari N2 untuk menghasilkan NH3 dilakukan melalui proses Haber−Bosch yang membutuhkan kondisi suhu dan tekanan yang sangat ekstrim sehingga mengonsumsi energi dalam jumlah tinggi dan mengemisikan CO2 dalam jumlah yang sangat besar. Oleh karena itu, perlu mengembangkan teknologi alternatif untuk sintesis amonia dengan metode yang ramah lingkungan. Banyak penelitian yang mengembangkan konversi nitrogen menjadi amonia secara fotoelektrokimia dengan adanya material semikonduktor, namun efisiensi yang dihasilkan masih belum cukup baik, sehingga perlu untuk dikembangkan lebih lanjut. Pada penelitian ini dilakukan pengembangan sistem tandem Dye Sensitized Solar Cell-Photoelectrochemistry (DSSC-PEC) untuk konversi nitrogen menjadi amonia. Sel DSSC disusun menggunakan fotoanoda N719/TiO2NTs, elektrolit I-/I3-, dan katoda Pt/FTO. Efisiensi DSSC yang dihasilkan pada penelitian ini sebesar 1,49%. Sel PEC disusun menggunakan BiOBr/TiO2NTs yang disintesis dengan metode successive ionic layer adsorption and reaction (SILAR) sebagai katoda, tempat berlangsungnya reaksi konversi nitrogen menjadi amonia, dan Ti3+/TiO2NTs sebagai fotoanoda tempat berlangsungnya oksidasi air. Selain itu, pada penelitian ini juga dilakukan variasi ketika Ti3+/TiO2NTs digunakan sebagai fotoanoda dan BiOBr/TiO2NTs sebagai katoda beserta BiOBr/TiO2NTs sebagai fotoanoda dan katoda. Sistem tandem disusun dengan menghubungkan anoda PEC dengan katoda DSSC, serta katoda PEC dengan anoda DSSC menggunakan kawat tembaga. Kadar amonia yang dihasilkan dianalisis dengan menggunakan metode fenat. Pada penelitian ini diperoleh kadar amonia tertinggi dengan sistem yang menggunakan material BiOBr/TiO2NTs pada anoda dan katoda dengan kadar amonia yang dihasilkan sebesar 0,1272 µmol selama 6 jam, dengan persen solar to chemical conversion (SCC) sebesar 0,0021%.

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Ammonia is an important compound for human’s life, including in industry and agriculture. The demand for ammonia is expected to increase every year. Conventionally, the industrial fixation of N2 to NH3 is carried out through the Haber−Bosch process which requires extreme conditions of temperature and pressure. This process consumes a high amount of energy and emits a very large amount of CO2. Therefore, it is necessary to develop alternative technologies for ammonia synthesis using environmentally friendly methods. Many studies have developed the photoelectrochemical conversion of nitrogen to ammonia in the presence of semiconductor materials, but the resulting efficiency is still not good enough, so it needs further development. In this research, the development of the tandem system of Dye Sensitized Solar Cell-Photoelectrochemistry (DSSC-PEC) was carried out for the conversion of nitrogen to ammonia. DSSC cells were prepared using N719/TiO2NTs photoanode, I-/I3- electrolyte, and Pt/FTO cathode. The DSSC efficiency produced in this research is 1.49%. PEC cells were prepared using BiOBr/TiO2NTs synthesized by the successive ionic layer adsorption and reaction (SILAR) method as the cathode, where the reaction of converting nitrogen into ammonia takes place, and Ti3+/TiO2NTs as the photoanode where water oxidation takes place. In addition, in this study we also did the various experiments when Ti3+/TiO2NTs were used as photoanode and BiOBr/TiO2NTs as cathode, as well as BiOBr/TiO2NTs as photoanode and cathode. The tandem system is arranged by connecting the PEC anode to the DSSC cathode and the PEC cathode to the DSSC anode using copper wire. The resulting ammonia levels were analyzed using the phenate method. In this study, the highest ammonia levels were obtained with a system using BiOBr/TiO2NTs material at the anode and cathode with the resulting ammonia of 0.1272 µmol for 6 hours, with an solar to chemical (SCC) value of 0.0021%."

"Saat ini kebutuhan manusia akan energi semakin meningkat. Energi berbahan bakarfosil masih menjadi sumber utama energi untuk memenuhi kebutuhan manusia.Namun, karena sifatnya yang tidak dapat diperbaharui, energi fosil tersebut lamakelamaan akan habis. Oleh karena itu diperlukan energi alternatif yang dapatdiperbaharui dan juga ramah lingkungan. Energi alternatif tersebut salah satunyaadalah energi surya. Energi surya dapat dikonversi menjadi energi listrik denganmenggunakan perangkat Dye-Sensitized Solar Cell (DSSC). Pada penelitian iniakan dibuat perangkat DSSC dengan menggunakan ekstrak antosianin dari kolmerah sebagai dye sensitizer, TiO2 nanorod sebagai semikonduktor, larutanelektrolit (I-/I3-), serta platina sebagai elektroda pembanding. TiO2 nanorod yangdigunakan untuk menyusun rangkaian DSSC disiapkan dengan cara hidrotermaldan dengan tiga variasi suhu kalsinasi diantaranya tanpa perlakuan kalsinasi,dikalsinasi pada suhu 450oC, dan dikalsinasi pada suhu 900oC. Waktu perendamandeposisi pasta TiO2 dalam dyes dilakukan selama 36 jam. Seluruh rangkaian DSSCyang disusun ditentukan efesiensinya secara fotoelektrokimia, denganmenggunakan evaluasi berdasar I – V dan didapatkan nilai efesiensi DSSC TiO2nanorod tanpa kalsinasi, dikalsinasi pada suhu 450oC, dan dikalsinasi pada suhu900oC berturut-turut sebesar 1,125%, 0,399%, dan 0,306%. Nilai efesiensi tertinggididapatkan pada rangkaian DSSC TiO2 nanorod tanpa kalsinasi yaitu sebesar1,125%

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Human need for energy is increasing over time. Fossil fuel energy is still the mainsource of energy. However, due to its non-renewable nature, this fossil energy willrun out. Therefore we need alternative energy that can be renewed as well asenvironmentally friendly. One of the alternative energy is solar energy. Solarenergy can be converted into electrical energy using a Dye-Sensitized Solar Cell(DSSC) device. In this research, a DSSC device will be constructed usinganthocyanin extract from red cabbage as a dye sensitizer, TiO2 nanorod as asemiconductor, I- / I3- redox couple as electrolyte solution, and Pt as a counterelectrode. TiO2 nanorod used to assemble the DSSC device was prepared byhydrothermal method, followed by heat treatment into three variations of thecalcination temperature, these were without calcination treatment, calcined at atemperature of 450oC, and calcined at a temperature of 900oC. The immersion timeof TiO2 paste deposition in dyes solution for the deposition was carried out for 36hours. The three constructed DSSCs series were tested for their efficiency usingphotoelectrochemical system, by evaluating their resulted the I-V curves and theefficiency values of the DSSC TiO2 nanorod without calcination, calcined at atemperature of 450oC, and calcined at 900oC were 1.125%, 0.399%, and 0.306%respectively. The highest efficiency value was obtained in the DSSC TiO2 nanorodwithout calcination with efficiency of 1.125%."

"Fokus dari penelitian ini adalah meneliti "Self-propagating high temperature synthesis"(SHS) dari titanium karbida (TiC). Penekanan dari penelitian ini adalah untuk mempelajari pengetahuan dasar tentang SHS yang digunakan untuk memproduksi titanium karbida yang diharapkan akan memiliki karakteristik seperti porositas yang sangat tinggi, luas permukaan yang sangat luas, dan material yang baik dalam transfer/difusi elektron (karakteristik ini seperti yang pada umumnya dimililki oleh semikonduktor yang memiliki pita lebar). Hasil dari proses sintesis ini akan dimaanfatkan pada dye-­‐sensitized solar cell dan diprediksi dapat meningkatkan keefektifannya. Teknik pengolahan baru seperti SHS ini memiliki kemampuan untuk menghasilkan material dengan porositas tinggi dengan sangat cepat yang dimana sulit dilakukan dengan teknik pengolahan lain. Teknik pengolahan ini juga mampu membuat produk yang sangat dekat dengan hasil akhirnya, atau dengan kata lain produk dari SHS ini tidak memerlukan proses finishing yang rumit. SHS memiliki keunikan yaitu parameter-­‐parameter pengolahannya dapat diatur sedemikian rupa sesuai dengan kebutuhan dan hasil akhir yang di inginkan [2]. Hasil dari eksperimen pertama ini sangat menjanjikan oleh karena itu proyek ini akan dibawa ketingkat yang selanjutnya. Proses sintesis pembakaran berhasil memproduksi sampel utuh titanium karbida dari campuran titanium dan serbuk karbon yang tidak di padatkan. Meskipun serbuk titanium telah terkontaminasi oksidasi di karenakan pembungkusan yang tidak sempurna dan juga tidak diketahuinya properti dari serbuk karbon yang digunakan, produk dari sintesis percobaan pertama ini menjanjikan yaitu produk yang dihasilkan memiliki porositas yang tinggi sesuai yang di inginkan. Karakterisasi lebih lanjut dari produk hasil eksperimen ini akan dilakukan, serta karekaterisasi dari sampel awal yang digunakan untuk tujuan perbandingan.

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The focus of the research herein examines the Self-propagating High temperature Synthesis (SHS) of titanium carbide (TiC).

The emphasis of this research is to study the fundamental knowledge on the SHS produced titanium carbide material with ultra-high porosity, surface area, and electron transfer/diffusion(e.g. wide band gap semiconductors). Furthermore, the engineered porous material will be used in a Dye-Sensitized Solar Cell (DSSC) to improve its efficieny.

Novel processing techniques such as self-propagating high temperature synthesis have the capability to rapidly produce advanced porous materials that are difficult to fabricate via other method. This processing technique is also capable to make near net shape materials. SHS provides the ability of using set processing parameters to produce a desired porous structure [2].

The results of primary experimentation were promising with regards to the continuation of the project. The combustion synthesis process was successful in producing an intact sample of titanium carbide from an un-compacted mixture of titanium and carbon powders.

Despite the oxidation contamination of the titanium powder at customs and the unknown properties of the carbon powder used, the product of the combustion synthesis has the first assessment desired property of high porosity. Further characterization of these samples will be undertaken, as well as processing of the green pellets for comparison purposes."