scholarly journals The Effect of Cu Doping on the Transformation from Rutile to Anatase and Cu Occupation Tendency in TiO2 Solid Solution

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Jun-Yu Chen ◽  
Ji-Kang Yan ◽  
Guo-You Gan

TiO2 doped with different amounts of Cu2+ ions (from 0 to 3 mol%) was synthesized by sol-gel method. The samples were characterized by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). The XRD analysis showed that the Cu-doped TiO2 samples exhibit anatase and rutile phases. The lattice parameters remain unchanged, independent of Cu2+ content. Diameter of TiO2 increased significantly with increasing concentrations of Cu2+. The investigated results indicate that a greater portion of the Cu2+ ions are well incorporated into the anatase and rutile TiO2 lattices. The stretching vibration frequencies of the interatomic bonds were calculated by the electronegativity principle. The calculated data were compared with infrared spectra. The results show that in the rutile and anatase phases, O atoms in the TiO2 lattice and some interstitial Cu atoms form Cu-O bond, and other substitutional Cu that replaces Ti atoms in TiO2 lattice form Cu-O bond with O atoms in the TiO2 lattice.

Arena Tekstil ◽  
2013 ◽  
Vol 28 (1) ◽  
Author(s):  
Maya Komalasari ◽  
Bambang Sunendar

Partikel nano TiO2 berbasis air dengan pH basa telah berhasil disintesis dengan menggunakan metode sol-gel dan diimobilisasi pada kain kapas dengan menggunakan kitosan sebagai zat pengikat silang. Sintesis dilakukan  dengan prekursor TiCl4 pada konsentrasi 0,3 M, 0,5 M dan 1 M, dan menggunakan templat kanji dengan proses kalsinasi pada suhu 500˚C selama 2 jam. Partikel nano TiO2 diaplikasikan ke kain kapas dengan metoda pad-dry-cure dan menggunakan kitosan sebagai crosslinking agent. Berdasarkan hasil Scanning Electron Microscope (SEM),diketahui bahwa morfologi partikel TiO2 berbentuk spherical dengan ukuran nano (kurang dari 100 nm). Karakterisasi X-Ray Diffraction (XRD) menunjukkan adanya tiga tipe struktur kristal utama, yaitu (100), (101) dan (102) dengan fasa kristal yang terbentuk adalah anatase dan rutile. Pada karakterisasi menggunakan SEM terhadap serbuk dari TiO2 yang telah diaplikasikan ke permukaan kain kapas, terlihat adanya imobilisasi partikel nano TiO2 melalui ikatan hidrogen silang dengan kitosan pada kain kapas. Hasil analisa tersebut kemudian dikonfirmasi dengan FTIR (Fourier Transform Infra Red) yang hasilnya memperlihatkan puncak serapan pada bilangan gelombang 3495 cm-1, 2546 cm-1, dan 511 cm-1,  yang masing-masing diasumsikan sebagai adanya vibrasi gugus fungsi O-H, N-H dan Ti-O-Ti. Hasil SEM menunjukkan pula bahwa kristal nano yang terbentuk diantaranya adalah fasa rutile , yang berdasarkan literatur terbukti dapatberfungsi sebagai anti UV.


2012 ◽  
Vol 476-478 ◽  
pp. 2059-2062
Author(s):  
Chen Wang ◽  
Ya Dong Li ◽  
Gu Qiao Ding

Tributyl borate was first adopted for the introduction of boron in the preparation of bioactive borosilicate xerogel by sol-gel method. The xerogel reacted continuously in 0.25M K2HPO4 solution with a starting pH value of 7.0 at 37 °C for 1day. The structural, morphologies and compositional changes resulting from the conversion were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The results indicated that speed of formation of HA was cut way back on the time with the addition of boron and the induction period for the HA nucleation on the surface of the borosilicate xerogel was short than 1 days. The conversion mechanism of the borosilicate xerogels to hydroxyapaptite was also discussed.


2018 ◽  
Vol 64 (4) ◽  
pp. 381
Author(s):  
Muhammad Tufiq Jamil ◽  
Javed Ahmad ◽  
Syed Hamad Bukhari ◽  
Murtaza Saleem

Rare earth nano sized pollycrystalline orthoferrites and orthocromites ReT mO3 (Re = La, Nd, Gd, Dy, Y and T m = Fe, Cr) have been synthesized by sol-gel auto combustion citrate method. The samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and UV-visible spectroscopy. The samples are single phase as confirmed by XRD analysis and correspond to the orthorhombic crystal symmetry with space group pbnm. Debye Scherer formula and Williamson Hall analysis have been used to calculate the average grain size which is consistent with that of determined from SEM analysis and varied between 25-75 nm. The elemental compositions of all samples have been checked by EDX analysis. Different crystallographic parameters are calculated with strong structural correlation among Re and Tm sites. The optical energy band gap has been calculated by using Tauc relation estimated to be in the range of 1.77 - 1.87 eV and 2.77 - 3.14 eV, for ReFeO3 and ReCrO3, respectively.


2015 ◽  
Vol 659 ◽  
pp. 121-126 ◽  
Author(s):  
Pat Sooksaen

Aluminium borate nanowhiskers with varying aspect ratio were synthesized via sol–gel synthesis. The morphology of aluminum borate (Al4B2O9 and Al18B4O33) nanowhiskers could be controlled by varying the aluminum to boron (Al:B) molar ratio in the sol–gel derived precursors. Sintering temperatures (850 and 1100°C) and sintering times (4 and 32 hours) also affected the phase composition and size of the nanowhiskers. Citric acid was also added in the sol–gel derived precursors as a surface stabilizer for obtaining uniform finely dispersed nanostructures. Fine nanowhiskers were obtained by the calcination at 850°C, whereas higher temperature of 1100°C led to thicker and longer nanowhiskers and became rod-like crystals. The morphology and phase composition were investigated by field emission scanning electron microscope and X-ray diffraction. Chemical bond vibrations in the synthesized nanowhiskers were investigated by Fourier-transform infrared spectroscopy.


al-Kimiya ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 91-99
Author(s):  
Ginawanti Maulida Gunawan ◽  
Dede Suhendar ◽  
Citra Deliana Dewi Sundari ◽  
Atthar Luqman Ivansyah ◽  
Soni Setiadji ◽  
...  

Tongkol jagung merupakan limbah agrikultural yang banyak mengandung silika yang pemanfaatannya belum maksimal. Silika dai tongkol jagung dapat menjadi solusi alternatif untuk menggantikan sumber silika komersial. Penelitian ini bertujuan untuk mengisolasi, mensintesis, dan mengkarakterisasi zeolit silikalit-1 dari limbah tongkol jagung. Metode sol-gel digunakan untuk mengisolasi silika yang selanjutnya digunakan untuk sintesis zeolit silikalit-1 dengan metode hidrotermal. Komposisi silika ditentukan oleh X-Ray Fluorescence (XRF). Silika yang dihasilkan sebesar 34,55%. Pengotor utama silika yang dihasilkan dari hasil ekstraksi adalah Na2O sebesar 7,48%. X-Ray Diffraction (XRD) menunjukkan bahwa silika hasil isolasi adalah amorf. Data Fourier Transform InfraRed (FTIR) menunjukkan adanya siloksan dan kelompok silanol didalam silika. X-Ray Diffraction (XRD) menunjukan bahwa zeolit silikalit-1 telah berhasil disintesis dengan ukuran kristal sebesar 15,28 nm. Data Fourier Transform InfraRed (FTIR) menunjukkan adanya gugus D5R pentasil pada zeolit yang dihasilkan. Scanning Electron Microscope (SEM) menunjukan morfologi dari zeolit silikalit-1 berbentuk bola-bola kecil yang merupakan benih kristal heksagonal yang sepenuhnya belum terbentuk.


2019 ◽  
Vol 7 (2) ◽  
pp. 203
Author(s):  
Harlina - Ardiyanti ◽  
Deska Lismawening Puspitarum ◽  
Weni Ayu Puja Kesuma

Telah dilakukan sintesis komposit Fe3O4/SiO2/TiO2 berbasis limbah ampas dengan kombinasi metode kopresipitasi dan sol gel. Proses sintesis terdiri dari 3 tahap, yaitu (1) preparasi nanopartikel Fe3O4 dengan metode kopresipitasi, (2) sintesis SiO2 dari limbah ampas tebu dengan metode sol gel, dan tahap akhir sintesis komposit Fe3O4/SiO2/TiO2. Karakterisasi X-ray Diffraction (XRD) menunjukkan struktur kristal dari komposit dan analisis gugus fungsi ditunjukkan dengan  Fourier Transform Infrared (FTIR) yang menunjukkan bahwa komposit telah berhasil disintesis. Aktivitas fotokatalis dari komposit diujikan  dengan pendegradasian zat warna Methylene Blue (MB) di bawah sinar matahari (visible light) selama 5 jam. Hasilnya menunjukkan bahwa komposit mempunyai aktivitas fotokatalis dan kemampuan degradasi MB yang lebih efektif dibandingkan dengan TiO2 murni. 


Author(s):  
Trinh Thi Loan ◽  
Nguyen Ngoc Long

The SnO2:Ni2+ powders with dopant contents ranging from 0.0 to 12 mol% have been synthesized by sol-gel method. The samples were characterized by X-ray diffraction (XRD) Raman spectroscopy, energy-dispersive X-ray spectrometer (EDS) and photoluminescense (PL) spectra. XRD analysis showed that samples doped with low Ni- concentrations exhibited single SnO2 crystalline phase, whereas the samples with high Ni- concentrations exhibited a mixture of SnO2 and NiO phases. The lattice parameters of the SnO2 host were independent on Ni2+ dopant content, while Raman mode positions were dependenton Ni2+ dopant content. The PL spectrum of the undoped SnO2 was characterized by the emission peaks due to near band edge (NBE) emission and the violet emission peaks associated with surface dangling bonds or oxygen vacancies and Sn interstitials.


2008 ◽  
Vol 47-50 ◽  
pp. 1063-1066 ◽  
Author(s):  
Costel Birsan ◽  
Cristina Ghitulica ◽  
Ecaterina Andronescu ◽  
Cristina Ionita ◽  
Mihaela Birsan

The aim of the study was the synthesis and characterization of bioactive osteoinductive glasses, in the SiO2 – CaO – P2O5 system. In order to maintain the bioactive character of bioglasses, for SiO2 contents higher than 60%, the sol – gel method was used for preparation. On the obtained powders, thermal, grain size and X - ray diffraction analysis were performed. The X - ray diffraction emphasized the formation of phosphate phases, whose proportion decreases as the silica content is increased. Later, the powders were thermally treated at temperatures between 1000 and 14000C, the phase composition evolution being monitored through XRD analysis. On the powder suspensions in physiological serum, the evolution of pH was investigated, in order to establish the chemical stability. The behavior of the obtained powders in physiological medium was studied, by immersing samples in simulated body fluid and excerpted after different periods of time.


Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 736 ◽  
Author(s):  
Aurelija Smalenskaite ◽  
Lina Pavasaryte ◽  
Thomas Yang ◽  
Aivaras Kareiva

The Mg3/Al and Mg3/Al0.99Eu0.01 layered double hydroxides (LDHs) were fabricated using a sol-gel chemistry approach and intercalated with different anions through ion exchange procedure. The influence of the origin of organic anion (oxalate, laurate, malonate, succinate, tartrate, benzoate, 1,3,5-benzentricarboxylate (BTC), 4-methylbenzoate (MB), 4-dimethylaminobenzoate (DMB) and 4-biphenylacetonate (BPhAc)) on the evolution of the chemical composition of the inorganic-organic LDHs system has been investigated. The obtained results indicated that the type and arrangement of organic guests between layers of the LDHs influence Eu3+ luminescence in the synthesized different hybrid inorganic–organic matrixes. For the characterization of synthesis products X-ray diffraction (XRD) analysis, infrared (FTIR) spectroscopy, fluorescence spectroscopy (FLS), and scanning electron microscopy (SEM), were used.


Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 728 ◽  
Author(s):  
Gheorghița Mitran ◽  
Florentina Neațu ◽  
Ștefan Neațu ◽  
Mihaela M. Trandafir ◽  
Mihaela Florea

The catalytic activity of a series of vanadium aluminophosphates catalysts prepared by sol-gel method followed by combustion of the obtained gel was evaluated in glycerol conversion towards methanol. The materials were characterized by several techniques such as X-ray diffraction (XRD), UV-vis, Fourier-transform infrared (FTIR), Raman and X-ray photoelectron (XPS) spectroscopies. The amount of vanadium incorporated in aluminophosphates framework played an important role in the catalytic activity, while in the products distribution the key role is played by the vanadium oxidation state on the surface. The sample that contains a large amount of V4+ has the highest selectivity towards methanol. On the sample with the lowest vanadium loading the oxidation path to dihydroxyacetone is predominant. The catalyst with higher content of tetrahedral isolated vanadium species, such V5APO, is less active in breaking the C–C bonds in the glycerol molecule than the one containing polymeric species.


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