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"Upaya untuk memproduksi hidrogen masih sedikit dari sumber yang terbarukan. TiO2 dalam bentuk nanotube arrays dengan dopan Boron yang disintesis dengan metode anodisasi untuk produksi hidrogen telah diinvestigasi. Perlakuan termal katalis B-TiO2 nanotube arrays (B-TNTAs) dilakukan dengan kalsinasi reduksi dengan gas hidrogen pada suhu 500oC selama 2 jam. Analisis SEM menunjukkan morfologi nanotube arrays tiap konsentrasi boron seragam. Analisis UV-Vis DRS menunjukkan B-TNTAs memiliki absorbansi yang besar pada jangkauan panjang gelombang sinar tampak dengan band gap energy yang relatif rendah yaitu menjadi 2,9 eV. Analisis XRD menunjukkan hasil 100% kristal anatase murni. Melalui proses fotokatalisis, hidrogen mampu dihasilkan hingga 48959 μmol/m2 setelah 4 jam pengujian dengan katalis 7,5 mM B-TNTAs.

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Attempts to produce hydrogen is still slightly from renewable sources. TiO2 nanotube arrays in the form of boron dopants synthesized by anodizing method for hydrogen production has been investigated. Catalyst-thermal treatment of TiO2 nanotube arrays B (B-TNTAs) performed by calcination reduction with hydrogen gas at a temperature of 500oC for 2 hours. SEM analysis showed the morphology of nanotube arrays by uniform boron concentration. UV-Vis DRS analysis showed B-TNTAs has a large absorbance in the visible wavelength range with a band gap energy is relatively low, to 2.9 eV. XRD analysis produces 100% anatase crystals. Through a photocatalytic process, hydrogen is able to produce up to 48959 μmol/m2 after 4 hours of testing with catalyst 7.5 mM B-TNTAs."

"Hydrogen is one of chemical industry feedstock and automobile fuel, which is commonly produced by electrolysis. Electrolysis, however, has several constraints that are primarily due to its large energy requirement. Plasma electrolysis is a breakthrough method that not only improves hydrogen production but also suppresses energy consumption. This research has been conducted to investigate the effectiveness of plasma electrolysis on hydrogen product quantity and energy consumption by varying the voltage and glycerol concentration. The results of this research showed that an increase in voltage led to increased hydrogen production and energy consumption; the addition of glycerol caused a decrease in hydrogen production but still resulted in an increase in energy consumption. The process effectiveness of plasma electrolysis at 300V and 0.1M KOH was 8.1 times higher than Faraday electrolysis."

"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."

"Modifications of the TiO2 P25 photocatalyst with metals: Platinum (Pt), Copper (Cu) and non-metal: Nitrogen (N) doping to produce Hydrogen (H2) from a glycerol-water mixture have been investigated. The metals (Pt and Cu) were loaded into Titanium Dioxide (TiO2 ) surface by employing an impregnation and Photo-Assisted Deposition (PAD) method, respectively. As prepared the metal doped TiO2 photocatalyst was then dispersed into an ammonia solution to obtain N-doped photocatalysts. The modified photocatalysts were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS). XRD patterns indicated that the modified TiO2 photocatalysts have a nano-size crystallite range of 16-23 nm, while the DRS analysis showed that the doping of both metal and non-metal into TiO2 photocatalysts could effectively shift photon absorption to the visible light region. The optimum Cu loading of Cu-N-TiO2 was found to be 5%, resulting in a 10 times higher H2 production improvement level when compared to unloaded TiO2, even though this is still considered to be inferior compared to that of a 1% Pt loading, which results in a 34 times higher level than an unmodified TiO2photocatalyst. The effect of glycerol concentrations on hydrogen production has also been studied. This method offers a promising technology to find renewable and clean energy by using cheap materials and a simple technology."

"This paper presents the production of hydrogen from various aqueous sources (de-ionized water, fufu effluent, sea water, run-off water, tap water, and urine). Two sets of hydrolysis experiments (with and without the dissolution of NaCl (35 g/l) into the aqueous media) were conducted using 12 V (DC supply) with graphite electrodes. The current utilized and volume of hydrogen produced was measured, while hydrogen flow rate, power, and effectiveness were estimated. The significance of the addition of NaCl to the aqueous media was analyzed using a t-test. It was observed that the dissolution of NaCl into the aqueous media had an appreciable effect on the values of pH, volume and flow rate of hydrogen produced, current utilized, power consumed, and effectiveness compared to the values obtained without NaCl dissolution. This was corroborated by the result of the t-test (tcritcal (2.0452) < tobserved (4.1139) with a p-value of 0.0032 at 95% confidence interval), indicating the significance of the dissolution of NaCl into the media. The results showed that urine, followed by sea water, fufu effluent, run-off water, tap water, and de-ionized water, had the highest volume and flow rate of hydrogen, whereas the value of effectiveness was highest for de-ionized water, followed by tap water, sea water, urine, fufu effluent, and run-off water. Run-off water and fufu effluent were also demonstrated to be potential sources of hydrogen production outside urine and sea water."

"Hidrazin hidrat (N2H4.H2O) telah dianggap sebagai bahan penyimpanan hidrogen berpotensi tinggi karena memiliki keunggulan seperti kandungan hidrogennya yang tinggi (8,0wt%) dan produk yang dihasilkan hanya berupa gas hidrogen dan nitrogen, sehingga tidak memerlukan proses pemisahan yang rumit dan aman untuk digunakan. Nanopartikel trimetalik NiCoPt dengan penyangga alumina disiapkan sebagai katalis yang efektif untuk dekomposisi hidrazin hidrat. γ-Al2O3 berukuran nano telah berhasil disintesis dengan metode presipitasi menggunakan aluminium nitrat yang kemudian diendapkan menggunakan ammonium hidroksida. Penggabungan penyangga γ-Al2O3 dengan nanopartikel nikel, kobalt, dan platina dilakukan melalui metode impregnasi basah menggunakan NiCl2.6H2O, CoCl2.6H2O, dan K2PtCl6 yang kemudian direduksi menggunakan NaBH4. Keberhasilan uji katalis ditentukan dengan aktivitas katalitik dan selektivitas hidrogen yang diperoleh dari alat gas buret. Pada uji katalis, diketahui bahwa nanopartikel Ni0,6Co0,2Pt0,2 merupakan variasi komposisi logam terbaik dengan γ-Al2O3 sebagai penyangga. Aktivitas katalitik yang terbaik dari katalis selanjutnya diuji pada variasi suhu untuk menghitung parameter kinetiknya. Penggunaan kembali sebanyak lima kali pada Ni0,6Co0,2Pt0,2/γ-Al2O3 menunjukkan aktivitas katalitik yang baik untuk dehidrogenasi hidrazin hidrat.

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Hydrazine hydrate (N2H4.H2O) has been considered as a high potential hydrogen storage material because it has advantages such as its high hydrogen content (8.0wt%) and the resulting product is only hydrogen and nitrogen gases, so it does not require a complicated separation process and is safe to use. Trimetallic NiCoPt nanoparticles with γ-Al2O3 support were prepared as an effective catalyst for the decomposition of hydrazine hydrate. Nano-sized γ-Al2O3 has been successfully synthesized by precipitation method using aluminum nitrate which was then precipitated using ammonium hydroxide. Incorporation of γ-Al2O3 support with nickel, cobalt, and platinum nanoparticles was carried out by wet impregnation method using NiCl2.6H2O, CoCl2.6H2O, and K2PtCl6 which was then reduced using NaBH4. The success of the catalyst test was determined by the catalytic activity and selectivity of the hydrogen obtained from the gas burette apparatus. In the catalyst test, it was found that Ni0,6Co0,2Pt0,2 nanoparticles were the best variations of metal composition with γ-Al2O3 as a support. The best catalytic activity of the catalyst was then tested at various temperatures to calculate its kinetic parameters. Five times reuse of Ni0,6Co0,2Pt0,2/γ-Al2O3 showed good catalytic activity for dehydrogenation of hydrazine hydrate."

"Kebutuhan bahan bakar fosil yang meningkat mengakibatkan ketersediaan bahan bakar fosil semakin menipis, sehingga sumber energi berbasis fosil memiliki harga yang tinggi. Oleh karena itu, dibutuhkan energi alternatif yang mampu untuk mengganti energi fosil menjadi energi yang dapat diperbarui dengan memanfaatkan cahaya matahari. Produksi hidrogen merupakan salah satu cara memanfaatkan kelebihan energi terbarukan. Salah satu usaha untuk meningkatkan produksi hidrogen (H2) pada suatu material semikonduktor sulfida logam adalah menghambat laju rekombinasi suatu material dan membuat sistem tandem dyes sensitized solar cell dengan photoelectrochemical cell (DSSC-PEC). Dalam penelitian ini dilakukan pengembangan sistem tandem DSSC-PEC untuk produksi H2. Katoda PEC berfungsi sebagai zona katalisis produksi hidrogen menggunakan Pt/TiO2NTAs, dan fotoanoda berfungsi sebagai oksidasi air menggunakan TiO2NTAs/Bi2S3 yang disintesis dengan mentode SILAR dengan berbagai variasi perbandingan komposisi dan variasi siklus. Sedangkan katoda DSSC menggunakan elektrolit I-/I3-, dan Pt/FTO, dan anoda menggunakan TiO2NTAs/N719. Semua material tersebut dikarakterisasi dengan MPA, UV-VIS DRS, XRD, dan SEM.Hasil penelitian menunjukkan bahwa fotoanoda dengan variasi perbandingan komposisi (1:1) pada siklus 2 menghasilkan respon arus terhadap cahaya yang paling optimum. Material ini memiliki respon terhadap sinar tampak, dengan energi celah pita sebesar 2,95 eV. Hal ini menunjukkan bahwa material fotoanoda tersebut memilki performa fotokatalitik yang lebih bagus jika dibandingkan dengan material tunggal TiO2NTAs, dan Bi2S3. Hasil difraktogram material TiO2NTAs/Bi2S3 memiliki kesesuaian dengan standar ICDD 01-074-9438 menghasilkan puncak difraksi pada 2Θ ( ͦ) 25, 28, 31, 35, 38, 40, 46, 48, 54, 55, 63, 70, dan 76 merupakan campuran dari TiO2 anatase, logam Ti, dan Bi2S3. Dari gambar SEM yang dihasilkan dengan metode sonikasi menunjukkan terjadinya bongkahan-bongkahan pada bentuk nanotubenya. Sedangkan dalam sistem tandem sel yang telah dikembangkan menghasilkan efisiensi Solar Cell sebesar 1,38 %. Dengan jumlah hidrogen yang dihasilkan pada kondisi penyinaran selama 6 jam sebesar 0,02318 %. Sedangkan tanpa adanya penyinaran hidrogen yang dihasilkan sebesar 0,000651%. Hal ini menunjukkan bahwa dengan adanya penyinaran mampu menghasilkan hidrogen lebih banyak dibandingkan dengan tanpa adanya penyinaran.

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The increasing need for fossil fuels has resulted in the availability of fossil fuels being depleted, so fossil-based energy sources have a high price. Therefore, alternative energy is needed that can replace fossil energy with renewable energy by utilizing sunlight. Hydrogen production is one way to take advantage of the advantages of renewable energy. One effort to increase the production of hydrogen (H2) in a metal sulfide semiconductor material is to inhibit the recombination rate of a material and create a tandem dye-sensitized solar cell system with a photoelectrochemical cell (DSSC-PEC). In this research, a tandem DSSC-PEC system was developed to produce H2. PEC cathode functions as a catalytic zone for hydrogen production using Pt/TiO2NTAs, and photoanode functions as water oxidation using TiO2NTAs/Bi2S3 synthesized by the SILAR method with various composition ratios and cycle variations. While the cathode of DSSC uses electrolytes I-/I3-, and Pt/FTO, and the anode uses TiO2NTAs/N719. All these materials were characterized by MPA, UV-VIS DRS, XRD, and SEM.

The results showed that photoanodes with varying composition ratios (1:1) in cycle 2 produced the most optimum current response to light. This material has a response to visible light, with a band gap energy of 2.95 eV. This shows that the photoanode material has a better photocatalytic performance when compared to the single materials TiO2NTas and Bi2S3. The results of the diffractogram of the TiO2NTAs/Bi2S3 material conforming to the ICDD standard 01-074-9438 producing diffraction peaks at 2Θ ( ͦ) 25, 28, 31, 35, 38, 40, 46, 48, 54, 55, 63, 70, and 76 is a mixture of TiO2 anatase, metal Ti, and Bi2S3. From the SEM image generated by the sonication method, it shows the occurrence of lumps in the shape of the nanotubes. Meanwhile, in the tandem cell system that has been developed, the efficiency of Solar Cell is 1.38%. With the amount of hydrogen produced under irradiation for 6 hours of 0.02318 %. Meanwhile, in the absence of irradiation, the resulting hydrogen is 0.000651%. This shows that the presence of irradiation is able to produce more hydrogen than without irradiation.

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"ABSTRAKSel QD-CdS-SSC termodifikasi terdiri dari dua zona yaitu zona QD-CdS-SSC dan zona katalitik. Zona QD-CdS-SSC berfungsi sebagai penangkap sinar, sedangkan zona katalitik merupakan tempat terjadinya reaksi katalitik untuk produksi hidrogen. Zona QD-CdS-SSC terdiri dari semikonduktor TiO2 yang disensitasi dengan CdS, larutan elektrolit polisulfida dan counter elektroda platina yang dilapiskan pada permukaan gelas berpenghantar dan transparan yaitu FTO Flour Tin Oxide . Plat titanium digunakan sebagai template untuk TiO2 nanotubes. Pada zona katalitik, untuk kepentingan reduksi H menjadi H2, platina dideposisikan pada permukan titanium. Pengujian produksi hidrogen dilakukan dengan irradiasi sinar visible pada zona QD-CdS-SSC dan counter elektroda BiVO4. Intensias lampu visible yang digunakan adalah 110 mW/cm2 dan 90 mW/cm2. Counter elektroda dengan zona QD-CdS-SSC dihubungkan dengan kawat tembaga. Larutan yang digunakan pada zona katalisis adalah 12,5 metanol dalam air. BiVO4 yang digunakan sebagai counter elektroda dalam sistem QD-CdS-SSC mampu menghasilkan hidrogen pada intensitas 110 mW/cm2 dan 90 mW/cm2 masing-masing sebesar 320,734 mol dan 20,872 mol.

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ABSTRACTModified QD CdS SSC has been successfully applied for hydrogen production. Modified QD CdS SSC cell consists of two zones there are QD CdS SSC and catalytic zone. QD CdS SSC zone serves to absorb light, while the catalytic zone is operate as the catalytic reaction site for hydrogen production. QD CdS SSC zone consists of TiO2 nanotubes sensitized by CdS immobilized on Ti plate, polysulfide electrolyte solution and platinum as counter electrode that is coated on the surface of FTO glass. Reduction of H to H2 occur on the platinum coated titanium at catalytic zone. Hydrogen production was performed by visible light irradiation on the QD CdS SSC zone and the counter electrode BiVO4 as well. The intensity of the visible light used was 110 mW cm2 and 90 mW cm2. Counter electrode and QD CdS SSC zone were connected by copper wire. The solution used in the catalytic zone in this study was 12.5 methanol in water. QD CdS SSC is able to produce hydrogen at an intensity of 110 mW cm2 and 90 mW cm2. Total hydrogen production at an intensity of 110 W cm2 and 90 mW cm2 were 320.734 mol and 20.872 mol respectively."

"The prospect of a device that uses solar energy to split water into H2 and O2 is highly attractive in terms of producinghydrogen as a carbon-neutral fuel. In this mini review, key research milestones that have been reached in this field overthe last two decades will be discussed, with special focus on devices that use earth-abundant materials. Finally, theremaining challenges in the development of such ?artificial leaves? will be highlighted.Daun Buatan: Perkembangan Terkini dan Tantangannya. Masa depan perangkat yang memanfaatkan energi matahariuntuk memisahkan molekul air menjadi H2 dan O2 sangat menarik, terutama dalam hal produksi hidrogen sebagai bahanbakar netral karbon. Dalam tinjauan singkat ini, penelitian penting yang telah dicapai dalam bidang ini selama duapuluhtahun terakhir akan dibahas, dengan perhatian khusus terhadap perangkat-perangkat yang menggunakan bahan yangbanyak terkandung dalam tanah. Terakhir, tantangan lainnya dalam pengembangan "Daun Artifisial" juga akandigarisbawahi."

"Salah satu teknologi produksi hidrogen yang ramah lingkungan adalah pemisahan air secara fotokatalitik dengan TiO2. Modifikasi TiO2 dengan dopan logam transisi Ni memerlukan bantuan promotor untuk memaksimalkan produksi hidrogen. Grafena dan g-C3N4 dapat berperan sebagai promotor bagi TiO2 karena memiliki kesamaan struktur 2D namun memiliki peran yang berbeda dalam produksi hidrogen secara fotokatalitik. Pada penelitian ini, loading Ni divariasikan pada Ni-G/TiO2 hingga diperoleh loading Ni terbaik dengan produksi hidrogen tertinggi, kemudian akan digunakan pada Ni-g-C3N4/TiO2 untuk membandingkan pengaruh promotor grafena dan g-C3N4. Karakterisasi fotokatalis dilakukan dengan analisis XRD, UV-Vis, dan FTIR. Uji produksi hidrogen dilakukan selama 4 jam dalam reaktor menggunakan lampu UV 20W dengan pencahayaan internal. Hasil uji produksi hidrogen untuk variasi loading Ni (0%, 0,5%, 1%, 2%, dan 4%) pada Ni-G/TiO2 berturut-turut sebesar 407,95 μmol, 450,62 μmol, 418,87 μmol, 477,89 μmol, dan 507,38 μmol. Sementara hasil uji produksi hidrogen pada TiO2 P25, g-C3N4, dan 4% Ni-g-C3N4/TiO2 berturut-turut sebesar 327,02 μmol, 291,93 μmol, dan 358,81 μmol. Hasil penelitian ini menunjukkan bahwa komposit 4% Ni-G/TiO2 merupakan alternatif yang menjanjikan untuk produksi hidrogen secara fotokatalitik karena menghasilkan hidrogen hingga 55% lebih tinggi dari TiO2 P25.

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One of environmentally friendly hydrogen production technologies is photocatalytic water-splitting with TiO2. Modification of TiO2 with transition metal Ni requires the help of promoter to maximize hydrogen production. Graphene and g-C3N4 can act as promoters for TiO2 because they have the same 2D structure but have different roles in photocatalytic hydrogen production. In this study, Ni loading was varied on Ni-G/TiO2 to obtain the best Ni loading with the highest hydrogen production, then it would be used on Ni-g-C3N4/TiO2 to compare the effect of graphene and g-C3N4 promoters. Photocatalyst characterization was carried out by XRD, UV-Vis, and FTIR analysis. Hydrogen production test was carried out for 4 hours in a reactor using 20W UV lamp with internal lighting. The results of the hydrogen production test for variations in Ni loading (0%, 0.5%, 1%, 2%, and 4%) on Ni-G/TiO2 were 407.95 μmol, 450.62 μmol, 418.87 μmol, 477.89 μmol, and 507.38 μmol. Meanwhile, the results of the hydrogen production test on TiO2 P25, g-C3N4 and 4% Ni-g-C3N4/TiO2 were 327.02 μmol, 291.93 μmol, and 358.81 μmol. The results of this study indicate that 4% Ni-G/TiO2 is a promising alternative for photocatalytic hydrogen production because it produces up to 55% higher than TiO2 P25.

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