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"ABSTRAKBahan bakar fosil yang menipis menjadi permasalahan energi saat ini. Hal tersebut meningkatkan pengembangan sumber energi terbarukan yang berkelanjutan dan bersifat ramah lingkungan. Bio-oil merupakan sumber energi berkelanjutan yang dihasilkan dari proses fast pyrolysis material organik serta material lain yang berpotensi sebagai sumber bio-oil, seperti senyawa guaiacol yang berasal dari bio-polimer lignin. Pada penelitian ini senyawa guaiacol digunakan sebagai senyawa model bio-oil, yang dikonversi melalui reaksi hidrodeoksigenasi HDO dengan metode catalytic transfer hydrogen untuk mengurangi kandungan oksigen serta mereduksi ikatan rangkap ? pada cincin aromatisnya. Reaksi HDO pada senyawa guaiacol dilakukan dengan menggunakan katalis heterogen Pd/TiO2 dan katalis bimetal M-Pd/TiO2 Co, Mo, dan Ni, serta pelarut 2-propanol sebagai sumber hidrogen. Variasi logam transisi pada katalis bimetal dilakukan untuk mengetahui pengaruh masing-masing logam terhadap aktivitas katalis Pd/TiO2. Preparasi katalis dilakukan dengan metode impregnasi kering atau incipient wetness dengan prekursor berupa: 1 garam PdCl2; 2 senyawa garam nitrat Co dan Ni; 3 garam ammonium molibdenum dan 4 penyangga Titania TiO2 P-25. Katalis hasil preparasi dianalisis menggunakan, TEM dan H2-TPR. Reaksi dari masing-masing katalis dilakukan menggunakan batch reactor pada suhu 250 C selama 1 jam dengan tekanan gas He sebesar 30 bar. Produk reaksi kemudian dianalisis menggunakan GC-FID, untuk menentukan persen konversi dari substrat berupa guaiacol. Katalis Ni-Pd/TiO2 menunjukan aktivitas yang tinggi terhadap reaksi HDO, dengan persen konversi guaiacol sebesar 31,21, serta persen konversi 2-propanol sebesar 16,26. Katalis ini kemudian direaksikan tanpa hadirnya pelarut 2-propanol, untuk melihat pengaruh 2-propanol sebagai sumber hidrogen. Rendahnya persen konversi sebesar 11,53 , menunjukan 2-propanol berperan dalam reaksi HDO sebagai penyedia hidrogen.

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ABSTRACTThe depletion of fossil fuel has become current energy issue that has been an attention of the development of renewable energy which sustainable and environmental friendly. Bio oil is a sustainable energy that produced from pyrolysis process of organic materials such as guaiacol compound derived from lignin bio polymers. In this study, guaiacol upgrading was used as a bio oil model compound in hydrodeoxygenation HDO reaction with Catalytic Transfer Hydrogen CTH by reducing oxygen content and double bond in the aromatic ring. Hydrodeoxygenation reaction of guaiacol was conducted by using heterogenous monometallic Pd TiO2 and bimetallic M Pd TiO2 M Co, Mo, and Ni catalysts, with 2 propanol as a hydrogen source. The addition of various transition metals to the bimetallic catalyst was performed to determine the effect of each metal on the activity of Pd TiO2 catalyst. The catalysts were synthesized by dry impregnation or incipient wetness method with precursors 1 PdCl2 salt 2 Co and Ni nitrate salt 3 ammonium moybdenum salt, and 4 supported catalyst titania TiO2 P 25. The prepared catalysts were characterized using TEM and H2 TPR. The HDO reaction of each catayst was carried out using a batch reactor at 250 C for 1 hour with 30 bar pressure of He gas. The reaction products were analyzed by GC FID to determine the conversion of guaiacol. The result showed that Ni Pd TiO2 catalyst exhibited a high activity of HDO reaction with conversion of guaiacol 32,21 and 16,26 for 2 propanol conversion percentage. This catalyst was then reacted with the same condition but without the presence of 2 propanol to evaluate the effect of alcohol solvent addition as the source of hydrogen. The low conversion percentage of guaiacol compound 11.53 showed that 2 propanol plays an important role as hydrogen source during the HDO reaction."

"Penambahan material Transition Metal Dichalcogedines (TMD) pada fotodetektor berbasis ZnO telah menarik banyak perhatian karena dapat meningkatkan kinerja fotodetektor. Material TMD yang digunakan pada pekerjaan ini adalah Tungsten disulfide (WS₂). WS₂ menunjukan sifat optik dan listrik yang lebih baik saat bentuknya berubah dari bulk menjadi monolayer. Pada pekerjaan ini, kami melaporkan pengaruh penambahan WS₂ nanosheet pada fotodetektor berbasis ZnO nanorods. ZnO disiapkan menggunakan metode hidrotermal selama 6 jam dan WS₂ disiapkan dengan metode liquid phase exfoliation selama 8 jam. Larutan WS₂ yang telah dieksfoliasi kemudian dideposisi di atas permukaan ZnO nanorods menggunakan metode spin coat. Sampel dikarakterisasi menggunakan SEM, TEM, EDS, Raman spektroskopi, UV-Vis spectrometer dan Uji fotodetektor dengan penyinaran cahaya 365, 505, dan 625 nm. Keberhasilan yang didapatkan dari penelitian ini adalah berupa penurunan nilai dark current yang terjadi akibat penambahan lapisan WS₂ di atas permukaan ZnO nanorods. Penurunan nilai dark current ini berdampak pada peningkatan ketiga parameter kinerja fotodetektor yaitu Sensitivitas, Responsivitas, dan Detektivitas yang dihitung pada tegangan 5V. Dibawah penyinaran sinar UV (365 nm) dengan daya 3.0 mW, nilai sensitivitas meningkat dari 129.06% menjadi 334.04%, nilai responsivitas meningkat dari 0.93 A/W menjadi 1.11 A/W, dan kemampuan detektivitas naik dari 2.5x10⁹ menjadi 4.4 x 10⁹ Jones.

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The addition of Transition Metal Dichalcogedines (TMD) towards the photodetector based on ZnO has attracted much attention due to their ability to improve the performance of photodetector. TMD that used in this work is Tungsten disulfide (WS₂). WS₂ shows better optical and electrical properties when it changed from bulk to monolayer. In this work, we report the effect of  WS₂ nanosheets addition to the performance of photodetector based on ZnO nanorods. ZnO were prepared by hydrothermal method for 6 hours and WS₂ were prepared by liquid phase exfoliation for 8 hours. Exfoliated WS₂ was deposited on the ZnO nanorods surface by spin-coating method. The sample was characterized by SEM, EDS, TEM, Raman spectroscopy, UV-Vis spectrometer, and photodetector test using 365, 505, and 625 nm incident lights. Our work has successfully lowered the dark current after WS₂ addition on ZnO nanorods surface. It has an impact to the enhancement of photodetector performances such as sensitivity, responsivity, and detectivity that measured at voltage bias 5V. Under the illumination of UV light with 3.0 mW power, the sensitivity increased from 129.06% to 334.04%, responsivity increased from 0.93 to 1.11 A/W, and the detectivity increased from 2.5 x 10⁹  to 4.4 x 10⁹ Jones."

"This book about electronic structures of oxo-metal ions, early days in kemisk laboratorium IV and later studies, transition metal corrole coordination chemistry. A review focusing on electronic structural studies, chemical sensing with semiconducting metal phthalocyanines, biological outer-sphere coordination, ligand field and molecular orbital theories of transition metal X-ray absorption edge transitions, and time-resolved X-ray diffraction : the dynamics of the chemical bond."

"This book about a chronicle about the development of electronic structure theories for transition metal complexes orbital models and electronic structure theory, sturmians and generalized sturmians in quantum theory, chemistry as a “manifestation of quantum phenomena” and the born–oppenheimer approximation?, from ligand field theory to molecular collision dynamics : a common thread of angular momentum, a modern first-principles view on ligand field theory through the eyes of correlated multireference wavefunctions, and the phase rule : beyond myopia to understanding."