scholarly journals Pengaruh Perbandingan Mol Awal Titanium dan Perak terhadap Sifat-Sifat Fisika-Kimia TiO2-tersensitifkan AgCl

2017 ◽  
pp. 106-115
Author(s):  
Isnaya Khamida Zulfah ◽  
Hari Sutrisno

Titanium dioksida (TiO2)merupakan semikonduktor yang memiliki fungsi sebagai fotokatalis, sel surya, anti bakteri, anti polutan, dan anti buram. Salah satu cara untuk meningkatkan aktifitas fungsional  TiO2dengan menggeser daerah aktifitas atau energi celah pita (Eg) dari sinar ultra violet (UV) ke daerah sinar tampak melalui penambahan zat pensensitif TiO2.Pada penelitian ini, perak klorida (AgCl) digunakan sebagai zat pensensitif TiO2. Tujuan penelitian ini untuk mengetahui pengaruh variasi perbandingan mol awal [Ti8O12(H2O)24]8.Cl8.HCl.7H2O dengan AgNO3 terhadap sifat-sifat fisik TiO2 tersensitifkan AgCl (TiO2@AgCl) yang disintesis dengan metode pengendapan basah dalam suasana asam. Variasi perbandingan awal yang digunakan yaitu perbandingan mol [Ti8O12(H2O)24]8.Cl8.HCl.7H2O :mol AgNO3sebesar 1:9, 1:10, 1:11, 1:12, dan 1:13yang dilarutkan dalam pelarut etanol (total pelarut 37.5 mL). Sampel padat TiO2@AgCl dihasilkan dengan metode pengendapan basah dalam kondisi asam melalui pengontrolan asam HNO3 pada pH~1. Sampel dihasilkan dari penguapan filtrat yang  bebas dari endapan AgCl, hingga volume yang didapat setengah dari volume awal. Sampel TiO2@AgCl dikarakterisasi dengan berbagai instrumen: Difraktometer Sinar-X (XRD),Scanning Electron Microscopy-Electron Dispersive X-Ray Analyzer (SEM-EDAX), dan Spektrofotometer UV-Vis Diffuse Reflectance. Hasil penelitian menunjukkan semua sampel TiO2@AgCl berisi 1 fasa nanopartikel (nanokristalit) TiO2 dan 3 fasa kristal yaitu rutil, anatas, dan AgCl.TiO2@AgCl memiliki bentuk morfologi berupa mikrosferik dengan ukuran berkisar 0.5-1 μm. Berdasarkan hasil analisisdengan spektrofotometer UV-Vis Diffuse Reflectance menunjukkan semua sampel TiO2@AgCl mengabsorbsi sinar ultra violet (UV) dengan Eg sebesar 2.87-3.89 eV, dan sinar tampak dengan Eg sebesar 1.60-2.40 eV. Titanium dioxide (TiO2) is a semiconductor that can be applied in the field of photocatalyst, solar cell, anti-bacterial, anti-pollutants, and anti-fogging. The functional activity of TiO2 can be increased by shifting the activity area from ultraviolet (UV) to visible through the addition of sensitizer. In this research, silver chloride (AgCl) was used as a sensitizer The objective of the research is to study the effect of the initial mole comparison of [Ti8O12(H2O)24]8.Cl8.HCl.7H2O and AgNO3on the physical properties of AgCl-sensitized TiO2(TiO2@AgCl). All TiO2@AgCl were synthesized using the wet chemical precipitation method under acidic conditions by the addition of a concentrated HNO3 with pH ~ 1. The initial comparison variation used was the mole ratio of [Ti8O12(H2O)24]8.Cl8.HCl.7H2O  : AgNO3 of 1: 9, 1:10, 1:11, 1:12, and 1:13. Each of these materials was dissolved in ethanol to 37.5 ml. All samples were produced from evaporation of filtrate free from AgCl precipitate, until the volume obtained half of the initial volume. The solid samples were characterized using X-Ray Diffractometer (XRD), Scanning Electron Microscopy-Electron Dispersive X-Ray Analyzer (SEM-EDAX), and UV-Vis spectrophotometer Diffuse Reflectance.The results showed that all samples of TiO2@AgCl consisted of 1 phase of TiO2-nanoparticles and 3 phases of rutile, anatase and AgCl crystals. The morphology of TiO2@AgCl is microspheric with a size ranging from 0.5-1 μm. Based on the results of the analysis with the UV-Vis spectrophotometer Diffuse Reflectance showed that all samples of TiO2@AgCl absorb ultraviolet (UV) rays with bandgap (Eg) ranging from 2.87 to 3.89 eV, and the visible light with Eg ranges from 1.60 to 2.40 eV.

2021 ◽  
Vol 49 (2) ◽  
pp. 030006052098533
Author(s):  
Jing-Yuan Peng ◽  
Michael George Botelho ◽  
Jukka Pekka Matinlinna ◽  
Hao-Bo Pan ◽  
Edwin Kukk ◽  
...  

Objective The effects of saliva on demineralized dentin and silver diamine fluoride (SDF) were investigated in vitro. Methods Dentin samples stored in deionized water (DIW), buffer solution (BS), basal medium mucin (BMM), and unstimulated whole saliva (UWS) were demineralized for 3 days and immersed in the same storage media. SDF as a 38 mass% solution was applied to the dentin samples for 3 minutes after they had been replaced in their respective medium. Surfaces were analyzed by scanning electron microscopy, energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Results Scanning electron microscopy showed various surface deposits and coatings, including occlusion of dentinal tubules. DIW resulted in the thinnest coating, whereas BMM resulted in the thickest. EDX and XPS showed the formation of metallic silver and silver compounds in all four media, with the greatest formation in BS. XRD indicated that the main product was silver chloride except in DIW. Sulphur was found in BMM and UWS. EDX and XPS detected fluoride and XRD detected calcium fluoride and fluorohydroxyapatite in BS, BMM, and UWS. Conclusion The interaction between SDF and demineralized dentin was dependent upon the storage medium. BMM provided an outcome most similar to human saliva.


2021 ◽  
Author(s):  
Fatma Unal

Abstract Terbium oxide (Tb2O3) particles (NPs) were synthesized by precipitation method using ammonium carbonate as precipitation agent. Effects of precursor molarity (0.1, 0.15 and 0.2 M) on photoluminescence (PL) behaviour of the NPs were investigated. The presence of the Tb2O3 phase was confirmed by X-Ray Diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) analyses. Morphological investigations of the produced powders were made by Field Emission Gun-Scanning Electron Microscopy (FEG-SEM). It showed that the morphology of Tb2O3 particles transformed from the nanograin chain to bundles morphology of rod-like as the amount of precursor molarity increased. Emission spectrum were investigated by Photoluminescence (PL) Spectroscopy. All the Tb2O3 particles exhibited the strongest peak at 493 nm ascribed to 5D4-7F6 (magnetic dipole (MD), C2) transition. The increase in the number of C2 sites released from the MD transition with the increase of the precursor molarity caused a negative increase in the b* (yellowness/blueness of the emission) value in the CIE diagram, indicating that the colour shifted to the blue region. The Tb2O3 particles produced by the precipitation method exhibited novel strong cyan colour and the PL emission intensity increased with increasing molarity.


2015 ◽  
Vol 230 ◽  
pp. 297-302 ◽  
Author(s):  
Oksana V. Livitska ◽  
Nataliya Yu. Strutynska ◽  
Igor V. Zatovsky ◽  
Nikolay S. Slobodyanik

The interaction in the systemsMII2P4O12-MICl (MINO3) (MI– Li, Na, K;MII– Mg, Co, Ni, Zn) was investigated in temperature range 1073-673 K. The conditions of formation phosphates: Li3PO4,MIMIIPO4(MI– Na, K), Na4MII3(PO4)2P2O7, Na9Co3(PO4)5have been established. Obtained crystalline phases have been investigated using X-ray powder diffraction, Diffuse reflectance, Raman and FTIR spectroscopy and scanning electron microscopy methods.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Rodholfo da Silva Barbosa Ferreira ◽  
Caio Henrique do Ó Pereira ◽  
Rene Anisio da Paz ◽  
Amanda Melissa Damião Leite ◽  
Edcleide Maria Araújo ◽  
...  

The nanocomposites have an extensive use in the current process of membrane preparation, taking into account their unique features as membranes. Thus, the study of nanocomposite processing to obtain membranes is highly important. In this work, Brazilian clay was used (Brasgel PA) for the preparation of polyamide/clay nanocomposite. The nanocomposites were produced in a high rotation homogenizer and in a twin screw extruder. From the nanocomposites and pure polymers processed in the two equipments, membranes were prepared by the immersion-precipitation method, using formic acid as solvent. By X-ray diffraction (XRD), the formation of exfoliated and/or partially exfoliated structures with changes in the crystalline phases of the polyamide was observed. From scanning electron microscopy images, it was observed that the processing clearly influenced the membrane morphology.


2017 ◽  
Vol 10 (02) ◽  
pp. 1750004 ◽  
Author(s):  
LiZhen Ren ◽  
DongEn Zhang ◽  
Xiao Yun Hao ◽  
Xin Xiao ◽  
Jun Yan Gong ◽  
...  

Bi2S3/SnS2 heterostructured photocatalysts were synthesized from BiOI, SnCl[Formula: see text]5H2O and NH2CSNH2 using an economic and simple hydrothermal method. The as-synthesized samples were characterized by X-ray diffraction, scanning electron microscopy and ultraviolet-visible diffuse reflectance spectroscopy. The photodegradation activities of the Bi2S3/SnS2 heterostructured photocatalysts were estimated by degrading rhodamine B under simulated sunlight supplied by irradiating with a 350[Formula: see text]W Xe lamp. Bi2S3/SnS2 photocatalysts were prepared using varying percentages of Bi2S3. The sample containing 13% Bi2S3 had the most efficient photocatalyst performance among the tested samples. The photocatalytic mechanism involves heterojunctions formed in the Bi2S3/SnS2, which promoted effective separation of photoinduced electrons and holes.


2010 ◽  
Vol 148-149 ◽  
pp. 1551-1555
Author(s):  
Yan Hong Zhao ◽  
Qing Yue Jia ◽  
You Gao ◽  
Xiao Jing Wang

Strontium carbonate particles with different morphologies and sizes were synthesized successfully by a precipitation method in the presence of ethylenediaminetetra-acetic acid disodium (abbreviate as EDTA) at 25 . The phase structure and morphology of these SrCO3 particles were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD results showed that orthorhombic crystalline SrCO3 particles were prepared in the absence of and presence of EDTA. It was found that this additive played an important role in controlling the morphology and size of the particles, which changed from dendritic to spherical shape as EDTA was added.


2011 ◽  
Vol 356-360 ◽  
pp. 2583-2586
Author(s):  
Li Xue ◽  
Ying Zhi Cheng ◽  
Xiu Yu Sun

Using cadmium acetate and sodium sulfuret as Cd and S sources, CdS samples were synthesized by chemical precipitation method. The conditions of supersaturation and aging time had been investigated, which could influence the activity of CdS for photocatalytic degrading methyl orange. The products were characterized by X-ray powder diffraction and field emission scanning electron microscopy. The CdS samples synthesized under low supersaturation showed better photocatalytic activities. A phase transformation of hexagonal CdS to cubic CdS was observed when CdS precipitation aging and the presence of proper amount of hexagonal CdS should improve the photocatalytic performance of cubic CdS.


NANO ◽  
2016 ◽  
Vol 11 (04) ◽  
pp. 1650041 ◽  
Author(s):  
Miguel A. Vallejo ◽  
Modesto A. Sosa ◽  
Esteban Rivera ◽  
Juan C. Azorín ◽  
Jesús Bernal ◽  
...  

In this paper, the co-precipitation method was used to synthesize pure and Ag-doped LiF crystals and the effect of crystalline cube sizes and Ag concentration on the thermoluminescent (TL) response is reported. The synthesized materials were characterized by scanning electron microscopy and their morphology and size distributions were determined. Crystal sizes were found to be strongly dependent on the ethanol:water ratio, varying from 4.1[Formula: see text][Formula: see text]m to 150[Formula: see text]nm for pure LiF crystals. For Ag-doped samples, the best ethanol:water ratio was found to be 9:1, giving crystals from 0.50[Formula: see text][Formula: see text]m to 1.21[Formula: see text][Formula: see text]m. A single cubic crystalline phase was determined by XRD for all synthesized samples. The photoluminescence spectra as well as UV-Vis absorbance were also analyzed. The TL response to X-ray irradiation was studied for an exposition of 43[Formula: see text]R. Two effects were observed in the TL response. The first concerns with a significant dependence of the TL intensity on the size of the crystals, being larger for the smallest crystals for pure LiF, and second, for Ag-doped samples the TL intensity augmented almost linearly with the Ag concentration.


2013 ◽  
Vol 454 ◽  
pp. 288-291 ◽  
Author(s):  
Jian An Liu ◽  
Mei Mei Zhang ◽  
Xue Na Yang

A novel porous ferromagnetic glass-ceramic has been synthesized with glassceramic and hydroxyapatite for hyperthermia application. The glassceramic was obtained from a melt derived glass, and the hydroxyapatite was prepared via precipitation method with biological template (YEAST). Both components of such a mixture were sintered at 1000 °C for 1 hour in graphite. The sample was characterized by x-ray diffraction, scanning electron microscopy and magnetic measurements. This material exhibited magnetic behavior and porosity. The results show that porous ferromagnetic glass-ceramic, which saturation magnetization (Ms) of about 25 A·m2/kg and diameter of porous 30-50μm, was obtained.


2017 ◽  
Vol 10 (04) ◽  
pp. 1750040 ◽  
Author(s):  
Xiaoyun Hao ◽  
Junyan Gong ◽  
Lizhen Ren ◽  
Dongen Zhang ◽  
Xin Xiao ◽  
...  

The polyaniline/bismuth oxybromide (PANI/BiOBr) hybrids materials have been synthesized hydrothermally in the presence of PANI. The PANI/BiOBr hybrids materials were confirmed by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy and ultraviolet–visible diffuse reflectance spectroscopies. Among the hybrid photocatalysts, PANI/BiOBr-0.2 showed the highest photocatalytic properties for the degradation of rhodamine B (RhB), and the increased photocatalytic properties could be due to photosensitization and the inhibited electron–hole recombination.


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