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"Optimasi berbagai parameter untuk preparasi fotokatalis TiO2 nanotubes dan TiO2 nanowires telah dilakukan, diantaranya dengan kombinasi proses sonikasi dan hidrotermal yang dilanjutkan dengan post treatment (kalsinasi atau hydrothermal post treatment) dan penambahan dopan logam (Cu, Pt) dan dopan nonlogam (N). Karakterisasi terhadap hasil sintesis dilakukan dengan menggunakan analisa TEM, SEM, BET, DRS dan XRD. Dari hasil analisa TEM dan SEM menunjukkan proses kombinasi sonikasi hidrothermal menggunakan NaOH diperoleh morfologi nanotubes dengan diameter luar 40 nm, sedangkan dengan KOH diperoleh struktur nanowires dengan diameter luar sebesar 6 nm. Hasil pengujian XRD menunjukkan fasa kristal baik untuk nanotubes maupun nanowires yang dihasilkan adalah anatase. Uji aktifitas katalis untuk produksi hidrogen menggunakan sacrificial agent metanol.Dari hasil pengujian menunjukkan modifikasi TiO2 dari nanopartikel menjadi nanotubes dapat meningkatkan produksi hidrogen menjadi dua sampai tiga kalinya, sedangkan modifikasi ke bentuk nanowires menjadi dua kali dibandingkan TiO2 P25. Luas permukaan yang tinggi dan morfologi berongga pada nanotubes menyebabkan dispersi dopan Pt pada TiO2 nanotubes menjadi lebih baik sehingga mampu meningkatkan aktivitas fotokatalis dalam memproduksi hidrogen dari air hingga delapan belas kali lebih tinggi dibandingkan tanpa dopan platina. Pemberian dopan nitrogen pada fotokatalis TiO2 nanotube belum mampu menggeser panjang gelombang absorbansi secara signifikan sehingga dengan sumber foton sinar tampak belum dapat menghasilkan hidrogen yang cukup tinggi.

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Optimization of various parameters on the preparation of TiO2 nanotubes and TiO2 nanowires have been conducted, such as combination of sonication and hydrothermal process followed by post-treatment (calcination or hydrothermal post treatment) and the addition of dopant metal (Cu, Pt) and non-metallic dopants (N). The modified catalysts were characterized using TEM, SEM, BET, DRS and XRD. The TEM and SEM analysis showed that the sonication-hydrothermal treatment with aqueous NaOH and KOH lead to the formation of nanotubes and nanowires morphology with an average outer diameter of 40 nm and 6 nm, respectively. XRD analysis showed that the both morphologies have anatase crystalline phase. Performance of the prepared photocatalyst on hydrogen production was examined by using methanol as sacrificial agent.The results indicated the modification of TiO2 nanoparticles into nanotubes could increased in producing hydrogen two-three fold, while the modification to the nanowires into two fold comparing to that of unmodified TiO2 (P25). Larger surface area and porous morphology in nanotubes enhanced the Pt dopant dispersion on TiO2 NT to increase the photocatalyst activity. Furthermore, this increased the production of hydrogen by 18 fold compared to that of non doped TiO2 nanotubes. However introduction of N dopant to the TiO2 nanotubes was not able to shift the absorbtion band toward visible region. Therefore, the high yield of hydrogen production was not achieved by as prepared N doped TiO2, when visible light was used as the photon source."

"Titania nanotubes (TiO2 NT) and Titania nanowires (TiO2 NW) were fabricated using TiO2 Degussa P25 (TiO2 P25) nanoparticle as precursors via a sonication-hydrothermal combination approach. The prepared catalysts were characterized by means of an X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), ultraviolet-visible diffuse reflectance spectroscopy (DRS) and the Brunauer-Emmett-Teller technique (BET). The photocatalytic activity of prepared catalysts was evaluated for photocatalytic H2 evolution from an aqueous methanol solution. The results showed that activity of the catalyst not only depends on the morphology of its catalysts, but also on the crystalinity and surface area. Hydrogen production of TiO2 NT was about three times higher than TiO2 P25 and TiO2 NW was two times higher than TiO2P25."

"[ABSTRAKSintesis TiO2 bermorfologi nanotube array bentuk film (TNTAs) telah dilakukan dengan proses anodisasi logam Ti dalam larutan elektrolit gliserol yang mengandung NH4F, dilanjutkan dengan annealing untuk membuat fasa kristal dari TNTAs. Optimasi berbagai parameter meliputi variasi kadar air dalam larutan elektrolit, perlakuan annealing, penambahan NaBF4, metode dan lama pengadukan serta variasi loading dan metode dalam penambahan dopan logam Pt. Hasil SEM/FESEM menunjukkan bahwa TNTAs berhasil disintesis dengan tube yang rapi, tegak lurus dan mempunyai kisaran diameter dalam antara 49-205 nm, tebal dinding 11-33 nm serta panjang 530-2577 nm. Annealing dengan H2/Ar merupakan cara yang efisien untuk memasukkan dopan C, N dan B dalam matrik TNTAs secara insitu saat anodisasi, sehingga diperoleh penurunan energi band gap sampai pada kisaran 2,20?3,10 eV. Kebanyakan TNTAs berfasa anatase dengan ukuran kristal dari 18?33 nm. TNTAs yang disintesis pada kadar air 25% volume dan annealing dengan 20% H2/Ar merupakan fotokatalis optimal yang menghasilkan kerapatan arus tertinggi. Uji TNTAs untuk memproduksi hidrogen menggunakan gliserol sebagai sacrificial agent. Penambahan 5 mM NaBF4 selama anodisasi menghasilan TNTAs termodifikasi yang mampu menghambat laju rekombinasi elektron-hole sehingga dapat meningkatkan produksi hidrogen sebesar 32 %. Penambahan dopan Pt sebagai electron trapper secara fotodeposisi pada TNTAs hasil anodisasi ultrasonik mampu menghasilkan hidrogen dari larutan gliserol sebesar lima kali lebih tinggi dibandingkan tanpa penambahan Pt.;

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ABSTRACTSynthesis of TiO2 nanotube array (TNTAs) has been performed by anodization process of Ti metal in the glycerol electrolyte solution containing NH4F followed by annealing to induce crystallization. Optimization some parameters was done including the variation of water content in the electrolyte solution, annealing atmosphere, addition of NaBF4, mode of mixing, as well as the variation of loading and the methods of Pt addition on the TNTAs. SEM/FESEM analysis showed that well ordered and vertically oriented of TNTAs with inner diameters of 49-205 nm, wall thicknesses from 11 to 33 nm and lengths from 530 to 2577 nm were synthesized. Annealing with H2/Ar is found to be an efficient method for introducing dopant C, N and B into the lattice of TNTAs via insitu anodization and, therefore, the reducing band gap in the range of 2,20?3,10 eV can be obtained. Most of TNTAs have anatase phase with the crystalline size from 18 to 33 nm. Water content of 25 v% and annealing under H2/Ar of as-synt TNTAs showed optimal condition in producing the highest photocurrent density. The photocatalytic hydrogen production test was performed with glycerol as a sacrificial agent. The addition of 5 mM NaBF4 during anodization resulted modified TNTAs that can reduce recombination of electron-hole and showed up 32 % improvement in hydrogen production. The photodeposition of Pt on the TNTAs that obtained from ultrasonic anodization can enhance hydrogen production five times higher compare to the one with unplatinized TNTAs.;Synthesis of TiO2 nanotube array (TNTAs) has been performed by anodization process of Ti metal in the glycerol electrolyte solution containing NH4F followed by annealing to induce crystallization. Optimization some parameters was done including the variation of water content in the electrolyte solution, annealing atmosphere, addition of NaBF4, mode of mixing, as well as the variation of loading and the methods of Pt addition on the TNTAs. SEM/FESEM analysis showed that well ordered and vertically oriented of TNTAs with inner diameters of 49-205 nm, wall thicknesses from 11 to 33 nm and lengths from 530 to 2577 nm were synthesized. Annealing with H2/Ar is found to be an efficient method for introducing dopant C, N and B into the lattice of TNTAs via insitu anodization and, therefore, the reducing band gap in the range of 2,20?3,10 eV can be obtained. Most of TNTAs have anatase phase with the crystalline size from 18 to 33 nm. Water content of 25 v% and annealing under H2/Ar of as-synt TNTAs showed optimal condition in producing the highest photocurrent density. The photocatalytic hydrogen production test was performed with glycerol as a sacrificial agent. The addition of 5 mM NaBF4 during anodization resulted modified TNTAs that can reduce recombination of electron-hole and showed up 32 % improvement in hydrogen production. The photodeposition of Pt on the TNTAs that obtained from ultrasonic anodization can enhance hydrogen production five times higher compare to the one with unplatinized TNTAs., Synthesis of TiO2 nanotube array (TNTAs) has been performed by anodization process of Ti metal in the glycerol electrolyte solution containing NH4F followed by annealing to induce crystallization. Optimization some parameters was done including the variation of water content in the electrolyte solution, annealing atmosphere, addition of NaBF4, mode of mixing, as well as the variation of loading and the methods of Pt addition on the TNTAs. SEM/FESEM analysis showed that well ordered and vertically oriented of TNTAs with inner diameters of 49-205 nm, wall thicknesses from 11 to 33 nm and lengths from 530 to 2577 nm were synthesized. Annealing with H2/Ar is found to be an efficient method for introducing dopant C, N and B into the lattice of TNTAs via insitu anodization and, therefore, the reducing band gap in the range of 2,20–3,10 eV can be obtained. Most of TNTAs have anatase phase with the crystalline size from 18 to 33 nm. Water content of 25 v% and annealing under H2/Ar of as-synt TNTAs showed optimal condition in producing the highest photocurrent density. The photocatalytic hydrogen production test was performed with glycerol as a sacrificial agent. The addition of 5 mM NaBF4 during anodization resulted modified TNTAs that can reduce recombination of electron-hole and showed up 32 % improvement in hydrogen production. The photodeposition of Pt on the TNTAs that obtained from ultrasonic anodization can enhance hydrogen production five times higher compare to the one with unplatinized TNTAs.]"

"Titania nanotube (TNT)-carbon nanotube (CNT) composite had been successfully synthesized using simple mixing under acidic conditions and ultrasonic treatment. The samples were further characterized via field emission scanning electron microscopy (FESEM), X–ray diffraction (XRD), diffuse re?ectance UV-vis spectroscopy, and Brunauer-Emmett-Teller (BET) analysis. The TNT–CNT composite’s ability to degrade phenol, a model of industrial waste, was tested. The effects of CNT composition and calcination temperature on the phenol degradation performance of TNT-CNT composite were investigated. The results show that the TNT-CNT composite exhibits higher photocatalytic activity than TNT or CNT alone. The crystallinity of the catalyst is not the only parameter affecting the photocatalytic activity. Rather, the specific surface area, bandgap, and morphology of the catalyst must also be considered."

"Fabrikasi Dye-Sensitized Solar Cell (DSSC)menggunakan klorofil dan rhodamin B telah berhasil dilakukan.Bahan semikonduktor sebagai elektroda kerja dalam DSSC yang digunakan adalah TiO2nanotube yang ditumbuhkan pada plat titanium dengan teknik anodisasi, dilanjutkan dengan kalsinasi pada 500⁰C untuk membentuk fasa kristal TiO2. Karakterisasi terhadap Ti/TiO2-NT meliputi Field Emission Scanning Electron Microscope(FE-SEM), UV-VisDiffuse Reflectance Spectrometry (DRS), X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), dan Linear Sweep Voltametry (LSV). Gambar FE-SEM menunjukkan bahwa TiO2 bermorfologi tube dengan diameter 88.99nm. Pola XRD menunjukkan puncak TiO2 anatase pada sudut 2θ: 25, 37,48,54, dan 55 derajat. Karakterisasi UV-Vis menunjukkan nilai bandgap TiO2 sebesar 3.24 eV. Spektrum FTIR menunjukkan keberadaan vibrasi ikatan ~Ti-O-Ti~. Kurva LSV menunjukkan bahwa TiO2 aktif pada daerah UV. Plat Ti/TiO2 dilapisi oleh zat warna melalui teknik elektroforesis dengan variasi waktu 8,10,12, dan 14 menit. Spektrum UV-Vis DRS dari TiO2 yang terlapisi zat warna menghasilkan puncak khas dari masing-masing zat warna, menunjukkan bahwa zat warna telah menempel pada TiO2. Pengujian terhadap performa DSSC menunjukkan nilai efiensi sebesar 0.3565% untuk Ti/TiO2-NT/Klorofil; 0.4351% untuk Ti/TiO2-NT/Rhodamin B; dan 0.3963% untuk Ti/TiO2-NT/Klorofil-Rhodamin B.Indonesia

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Fabrication of Dye-Sensitized Solar Cell (DSSC) employing chlorophyll and rhodamine B has been successfully carried out. TiO2 nanotubes which was grown on titanium plate by an anodizationtechniques, followed by calcination at 500⁰C to form a crystalline phase of TiO2, was used as working electrode in the DSSC. Characterization of the Ti/TiO2-NT included Field Emission Scanning Electron Microscope (FE-SEM), UV-Vis Diffuse Reflectance Spectrometry (DRS), X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), and Linear Sweep Voltametry (LSV). FE-SEM images showed the tube morphologies of TiO2 with a diameter of 88,99 nm. XRD pattern showed the TiO2 anatase peak at 2θ : 25, 37, 48, 54, dan 55 degree. UV-Vis DRS characterization revealed that the bandgap of the prepared TiO2is 3.24 eV. FTIR spectrum showed the presence of ~Ti?O-Ti~ vibration. LSV curves obtained indicate that the TiO2is active in the UV region . The Ti/TiO2 plate then was being coated with the dye through electrophoresis technique with time variation of 8, 10, 12, and 14 minutes. UV-Vis DRS spectrum of the dyes coated TiO2 showed that all typical dyes realted peaks were observed, indicate that the dyes was attached to the Ti/TiO2-NT. Performance tests of the assembled DSSC showed the efficiencies of 0.3565%for the Ti/TiO2-NT/Chlorophyll; 0.4351% for the Ti/TiO2-NT/Rhodamine B; and 0.3963% for the Ti/TiO2-NT/Chlorophyll/Rhodamine B respectively."

"Material semikonduktor TiO2 yang digunakan sebagai fotoelektroda hanya dapat diaktifkan pada daerah sinar UV karena memiliki energi band gap yang relative besar. Untuk memperbaiki respon cahaya fotoelektroda, dilakukan pengembangan metode yang dapat mengubah respon fotokatalisis dari sinar UV ke sinar visible dengan menambahkan dopan karbon pada TiO2 nanotube. Menarik pula untuk diinvestigasi apabila sebelum dilakukan proses doping karbon, matriks TiO2 nanotube diperkaya terlebih dahulu dengan spesi Ti3+. Adanya spesi Ti3+ dapat memberikan hasil lebih baik daripada hanya menambahkan dopan karbon pada TiO2 nanotube. Spesi Ti3+ yang terdapat di dalam C-TiO2 nanotube diharapkan dapat memperkecil nilai energi band gap sehingga respon serapan sinar tampak lebih baik, arus cahaya yang dihasilkan lebih besar, dan meningkatkan kinerja fotoanoda dalam menghasilkan gas H2. Berdasarkan karakterisasi SEM, diameter tabung TiO2 nanotube yang dihasilkan rata-rata sebesar 68,92 nm. Dari karakterisasi XRD, didapatkan TiO2 nanotube yang berfasa anatase. Dari persamaan Kubelka-Munk, diperoleh nilai energi celah pita TiO2 nanotube sebesar 3,18 eV. Dari hasil MPA, arus cahaya TiO2 nanotube yang dihasilkan sinar UV (0,000011 mA/cm2) lebih tinggi daripada sinar visible (0,000007 mA/cm2). Hal ini menunjukkan bahwa TiO2 nanotube memiliki aktivitas fotokatalitik pada daerah sinar UV.

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Material of TiO2 semiconductor as a photoelectrode can only be activated in the UV light region because it has a relatively large band gap energy. To improve the photoelectrode, an effort was developed to shift the photocatalytic response visible light by adding carbon dopant in to TiO2 nanotube. It is also interesting to investigate if before the carbon doping process is carried out, the TiO2 nanotube matrix is enriched first with the Ti3+ species. The presence of Ti3+ species can give better results than just adding carbon dopant to TiO2 nanotube. Ti3+ species contained in C-TiO2 nanotube are expected to reduce the band gap energy value better response in visible light absorption, resulting higher photocurrent, and improve the performance of photoanode in producing H2 gas. Based on SEM characterization, tube diameter of TiO2 nanotube on average is 68,92 nm. From XRD characterization, obtained TiO2 nanotube which has an anatase phase. From Kubelka-Munk equation, band gap energy of TiO2 nanotube is 3,18 eV. From MPA result, photocurrent of TiO2 nanotube produced by UV light (0.000011 mA/cm2) is higher than visible light (0.000007 mA/cm2). This shows that TiO2 nanotube has photocatalytic activity in the UV light region."

"Pada penelitian ini, sintesis dan karakterisasi dari nanomaterial aerogel titania (TiO2) untuk tujuan aplikasi sel surya tersensitasi zat pewarna (DSSC) telah dilakukan. Aerogel TiO2 dengan luas permukaan yang tinggi telah berhasil dipreparasi melalui dua tahapan: proses sol–gel dengan rasio hidrolisis (Rw) 2.00, diikuti oleh proses ekstraksi super kritis kontinu menggunakan CO2. Untuk tujuan perbandingan, xerogel juga disintesis dengan metode pengeringan biasa pada temperatur ruang. Metode kalsinasi bertahap digunakan untuk merubah kedua sampel menjadi anatase polikristalin dengan memanaskannya pada 1500C dan 3000C, masing-masing selama 3 jam di bawah pengaruh gas N2 dan melanjutkan hingga temperatur kalsinasi di 4200C selama 2 jam, di bawah tiupan gas oksigen. Karakterisasi dari aerogel dan xerogel didapatkan menggunakan DTA, BET, XRD, UV-vis DRS, dan FTIR. Kedua sampel diintegrasikan menjadi DSSC, yang pengukuran tegangan sirkuit terbukanya (Voc) dilakukan di bawah sinar putih menggunakan multimeter. Hasil penelitian menunjukkan aerogel yang dipreparasi memiliki luas permukaan yang lebih tinggi (1975 m2/g) dari xerogel (271 m2/g). Telah dibuktikan pula bahwa proses kalsinasi bertahap mampu meningkatkan ukuran kristalit dari aerogel hingga 9,21 nm dengan tetap mempertahankan luas permukaannya (71,90 m2/g) lebih tinggi dari xerogel (67,90 m2/g). Hasil pengukuran Voc menunjukkan tegangan terbuka yang lebih tinggi pada DSSC aerogel (21,40 mV) daripada DSSC xerogel (1,10 mV).

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In this work, synthesis and characterization of nanomaterial titania (TiO2) aerogels for the purpose of dye-sensitized solar cells (DSSC) application have been performed. TiO2 aerogels with high surface area were succesfully prepared by two steps: sol–gel process with hydrolysis ratio (Rw) of 2.00, followed with continuous supercritical extraction with CO2. For comparison purposes, xerogels were also synthesized by conventional drying at room temperature. Multi-step calcination method was used to transform both samples to polycrystalline anatase by heating at 1500C and 3000C for 3 hours each under the influence of N2 gas and continuing to calcination temperature at 4200C for 2 hours, under oxygen flow (muffle).

The characteristics of aerogels and xerogels were obtained by DTA, BET, XRD, UV-vis DRS, and FTIR. Both samples were integrated into DSSC, which open voltage measurement (Voc) were performed under white light using multimeter. The results suggest aerogels prepared had higher surface area (1975 m2/g) than xerogels’ (271 m2/g). It was also proven multi-step calcination could increase crystallite size of aerogels to 9,21 nm by maintaining its surface area (71,90 m2/g), which is higher than that of xerogels (67,90 m2/g). The Voc measurement reveals a higher voltage on aerogel’s DSSC (21,40 mV) than that of xerogel (1,10 mV)."

"Carbon Nanotube (CNT) merupakan material multifungsi yang akan dibutuhkan dalam jumlah besar di masa depan. Terdapat metode yang sangat menjanjikan untuk memproduksi CNT dalam jumlah besar yaitu dengan Chemical Vapor Deposition (CVD) dalam reaktor unggun terfluidisasi. Oleh karena itu, penelitian ini difokuskan untuk dapat menghasilkan model reaktor unggun terfluidsasi sehingga dapat dikembangkan menjadi reaktor skala pabrik yang mampu memproduksi CNT dalam skala besar secara efisien. Persamaan peristiwa perpindahan untuk fenomena fisik yang berlangsung dalam reaktor akan dikombinasikan dengan persamaan kinetika reaksi dengan menggunakan Computational Fluid Dynamics (CFD) dalam COMSOL Multiphysics sehingga dihasilkan sebuah model reaktor. Selanjutnya model akan disimulasikan dengan variasi parameter proses. Hasil simulasi menunjukkan bahwa profil konsentrasi metana dipengaruhi oleh suhu dinding reaktor, rasio umpan, laju alir gas, tekanan umpan, dan ukuran katalis. Konversi metana dan yield karbon meningkat seiring dengan peningkatan suhu dinding reaktor, kandungan hidrogen dalam umpan, dan kecepatan fluida di dalam reaktor. Sedangkan konversi metana menurun seiring meningkatnya tekanan umpan dan ukuran katalis. Konversi metana pada model reaktor unggun terfluidisasi yang disimulasikan adalah sebesar 77% dengan Yield CNT yang dihasilkan sebesar 0.66 gCNT/gCat dalam waktu reaksi selama 5 jam.

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Carbon Nanotube (CNT) is well known material having an unique properties and will become future materials. Promising way to synthesize a large scale of CNT is through the Chemical Vapor Deposition in fluidized bed reactor. Focus of this research is to get fluidized bed reactor model which representate the condition and performance in the real reactor. Method of this research is develop model of mathematic equation based on mass, momentum, and energy balance. COMSOL Multiphysics is used to develop the model and for running simulation for several process parameter such as temperature, pressure, etc.

The simulation results show that the methane concentration profile is influenced by the temperature of the walls of the reactor, the feed ratio, gas flow rate, feed presure, and radius of catalyst particles. Conversion of methane and carbon yield increases with increasing temperature of the reactor wall, the addition hydrogen in reactant and the velocity of the fluid in the reactor. Conversion of methane decreases with increasing of feed pressure and radius of catalyst particles. In this model, conversion of methane was about 77% and Yield of CNT was about 0.66 gCNT/gCat for 5 hours of reaction."

"ABSTRAKProduksi nanotube karbon jenis Single Walled Nanotube Carbon (SWNT) danFew Walled Nanotube Carbon (FWNT) masih sulit untuk dilakukan. Salah satupenyebab utama adalah pemilihan katalis yang kurang tepat. Penelitian inimenggunakan katalis Fe/Mo/MgO untuk menghasilkan SWNT atau FWNT(diameter luar nanotube karbon kurang dari 10 nm). Katalis Fe/Mo/MgOdipreparasi dengan metode sol gel/spray coating. Nanokarbon akan dihasilkanmelalui reaksi dekomposisi katalitik metana pada suhu 850oC dengan katalisFe/Mo/MgO. Hasil penelitian menunjukkan konversi metana tertinggi mencapai97,64% dan yield karbon sebesar 1,48 gc/gkat. Nanokarbon kemudiandikarakterisasi dengan Transmission Electron Microscope (TEM). Nanokarbonyang dihasilkan pada penelitian ini terdiri atas nanotube karbon jenis FWNT(range diameter luar 4,5 nm ? 10 nm). Selain itu, MWNT (Multi Walled NanotubeCarbon, range diameter luar 10 nm ? 89,5 nm), carbon nanofiber, coil nanotube,dan bamboo-shaped carbon juga telah dihasilkan. Jenis nanokarbon yangdihasilkan bukan hanya jenis nanotube karbon disebabkan oleh waktu reaksi yangterlalu panjang serta diameter partikel katalis 20 nm hingga 100 nm yangterdeteksi dari hasil X-Ray Diffraction (XRD) dan Field Emmision ScanningElectron Microscope (FE SEM). Untuk memperbaiki hasil ini, running padapenelitian ini dilakukan sekali lagi dengan waktu reaksi 30 menit dengan waktureduksi 30 menit di suhu 850oC dan suhu kalsinasi 550oC di udara. Hasilnanokarbon yang diperoleh memiliki range diameter luar yang lebih kecil danberkisar antara 8,5 nm hingga 66,85 nm yang terukur pada FE SEM. Namun, jenisnanokarbon belum diketahui berupa FWNT atau MWNT atau nanokarbonlainnya.

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AbstractProduction of Single Walled Nanotubes Carbon (SWNT) dan Few WalledNanotubes Carbon (FWNT) is really hard to do recently. It occured due toinappropriate catalyst selection. Fe/Mo/MgO catalyst, used in literature, was usedto make nanotubes carbon. Fe/Mo/MgO catalyst was prepared by sol gel/spraycoating method and it would be reacted with methane in 850oC (methanedecomposition catalytic reaction). The research result shows that the highestmethane conversion reached 97,64% and carbon yield is 1,48 gc/gkat.Transmission Electron Microscope (TEM) indicated that the synthesized productwas FWNT (carbon nanotubes with outer diameter between 4,5 nm ? 10 nm),MWNT (Multi Walled Nanotubes Carbon, outer diameter between 10 nm ? 89,5nm), coil nanotube, carbon nanofiber, dan bamboo-shaped carbon. It is happeneddue to longer time reaction and catalyst diameters have range between 20 nm ?100 nm which detected by XRD and SEM characterization. Then, methanedecomposition catalytic reaction to get nanotube carbon was done once again inshorter times (30 minutes), longer time of reduction (40 minutes), and lowercalcination temperature (550oC) in air. FE SEM indicated that range of outerdiameter nanocarbon between 8,5 nm ? 66,85 nm but its types can not bedetermined by FE SEM."

"Pengaruh memodifikasi TiO2 dengan menggunakan dopan C dan batu apung dalam mendegradasi fenol dan Reactive Orange 7 telah di investigasi. Sumber dopan Carbon diperoleh dari 1-propanol. Pelapisan C-TiO2 pada batu apung diperoleh dari metode deep coating. Analisis UV-Vis DRS menunjukkan bahwa penurunan bandgap energy C-TiO2 menjadi 3,05 eV. Analisis BET menunjukkan luas permukan C-TiO2-batu apung adalah 3,539 m2/g. Konsentrasi fenol dan Reactive Orange 7 dianalisis dengan Spektrofotometer UV-Vis. Penambahan laju udara 100 ml/menit dapat meningkatkan kinerja komposit dengan tingkat degradasi mencapai 100% selama 2,5 jam. Konsentrasi awal fenol 10 ppm dapat didegradasi selama 0,8 jam dengan konstanta laju degradasi 1,26 menit-1.

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Effect of TiO2 modified by using dopants C and pumice in degrading phenol and Reactive Orange 7 was investigated. Source of dopant Carbon was obtained from 1-propanol. Coating C-TiO2 on pumice stone was obtained by deep coating process. UV-Vis DRS analysis showed that bandgap energy of C-TiO2 is reducing to 3.05 eV. BET analysis showed surface area of composite is 3.54 m2/g. The concentration of phenol and Reactive Orange 7 was analyzed by UV-Vis spectrophotometer. The addition rate of air 100 mL/min to enhance the performance of composite with degradation rates reached 100% for 2.5 hours. Initial phenol concentration of 10 ppm for 0,86 hours can be degraded by the degradation rate constant 1.26 min-1."