Latifa Hanum Lalasari

The Influence Of Deposition Time And Substrate Temperature Upon Spray Pyrolysis Process On The Resistivity And Optical Trasmittance Of 2 Persenwt Fluorine Doped Tin Oxide (Fto) Glass

Transparent conducting oxide (TCO) glasses play important role in many recent modern technologies including its application for dye sensitized solar cell. One of the most commonly used is indium tin oxide (ITO), however its price is rather expensive. Therefore, the main purpose of the current research is aimed at replacing ITO with fluorine-doped tin oxide (FTO) which is easier and more economic for fabrication. For this purpose, tin chloride dehydrate (SnCl2.2H2O) precursor doped with ammonium fluoride (NH4F) source by using sol-gel method and spray pyrolisis technique can be considered as a new breakthrough in the making of conductive glass. In this work, the ammonium floride was doped at a ratio of 2 wt persen to tin chloride precursor with variations of deposition time (10,20 and 30 minutes) and substrate temperature (250, 300 and 350 °C) upon spray pyrolysis technique. The results showed that the longer deposition time the thicker glass layer is, providing smaller resistivity. In this study, the highest transmittance of 75.5 persen and the lowest resistivity of 3,32 x 10-5 Ω.cm resitivitas were obtained from the glass subjected to 20 minutes deposition time and 300 oC substrate heating during the process. International Journal of Technology (2016) 8: 1335-1343

The effect of temperature and addition of reducing agent on sodium stannate preparation from cassiterite by the alkaline roasting process

Sodium stannate is an intermediate compound with the formula Na2SnO3. This compound is easily dissolved in water and has many applications in the electroplating industry, tin alloy production, and catalysts for organic synthesis. In this occasion was investigated the effect of temperature and the addition of reducing agent on making of sodium stannate phase from cassiterite by an alkaline roasting process using sodium carbonate (Na2CO3). Firstly, cassiterite was roasted at 700 °C for 3 hours and continued leaching process using 10% HCl solution at 110 °C for 2 hours. The cassiterite residue than was dried at 110 °C and mixed homogenously with a Na2CO3 decomposer at a mass ratio Na2CO3/cassiterite as 5:3 for the decomposition process. It was done by variation temperatures (300 °C, 700 °C, 800 °C, 870 °C, 900 °C) for 3 hours, variation times (3, 4, 5 hours) at a roasting temperature of 700 °C and addition of reducing agent such as sub-bituminous coal. The result of the experiment shows that cassiterite prepared by roasting and acid leaching process has the chemical composition as follows: 59.98% Sn, 22.58% O, 3.20% Ce, 3.15% La, 2.57% Nd, 1.67% Ti, 1.56% Fe, 1.24% P, 0.62% Ca and others. The Na2SnO3 phase begins to form at a roasting temperature of 870 °C for 3 hours. Although the roasting times was extended from 3 hours to 5 hours at 700 °C, the Na2SnO3 phase also has not yet formed. In other conditions, the addition of coal reducing agent to the roasting process would cause formations of Sn metal besides Na2SnO3 phase at 870 °C. At temperatures lower than 870 °C, the addition of coal only forms Sn metal, whereas the sodium stannate phase is not formed.Sodium stannate is an intermediate compound with the formula Na2SnO3. This compound is easily dissolved in water and has many applications in the electroplating industry, tin alloy production, and catalysts for organic synthesis. In this occasion was investigated the effect of temperature and the addition of reducing agent on making of sodium stannate phase from cassiterite by an alkaline roasting process using sodium carbonate (Na2CO3). Firstly, cassiterite was roasted at 700 °C for 3 hours and continued leaching process using 10% HCl solution at 110 °C for 2 hours. The cassiterite residue than was dried at 110 °C and mixed homogenously with a Na2CO3 decomposer at a mass ratio Na2CO3/cassiterite as 5:3 for the decomposition process. It was done by variation temperatures (300 °C, 700 °C, 800 °C, 870 °C, 900 °C) for 3 hours, variation times (3, 4, 5 hours) at a roasting temperature of 700 °C and addition of reducing agent such as sub-bituminous coal. The result of the experiment shows that cassiterite prep...

Electrical, optical and structural properties of FTO thin films fabricated by spray ultrasonic nebulizer technique from SnCl4 precursor

Thin films of fluorine-doped tin oxide on glass were prepared by spray ultrasonic nebulizer technique from an economic anhydrous tin (IV) chloride (SnCl4) precursor. The effect of deposition time on the structural, electrical and optical properties of tin oxide thin films was investigated. This research a purpose to find an optimum deposition time during spray pyrolysis technique in order to produce FTO with the desired characteristics. For this purpose, soda lime glasses are heated at 350 °C on deposition time of 10, 15, 20 and 25 minutes. NH4F was doped at a ratio of 2 wt% in the SnCl4 precursor and methanol solvent. The results revealed that longer deposition times created decreased the electrical resistivity and optical transmittance of FTO layers. The highest optical transmittance was 84.808% and the lowest resistivity was 4.01×10−5 Ω.cm, obtained from FTO glass subjected to a 15-minute deposition time at deposition temperature of 350 °C. This is accordance to the TCO conductive glass requirements for the minimum resistivity value on scale 10−4 Ω.cm and optical transmittance value of 80-85%.Thin films of fluorine-doped tin oxide on glass were prepared by spray ultrasonic nebulizer technique from an economic anhydrous tin (IV) chloride (SnCl4) precursor. The effect of deposition time on the structural, electrical and optical properties of tin oxide thin films was investigated. This research a purpose to find an optimum deposition time during spray pyrolysis technique in order to produce FTO with the desired characteristics. For this purpose, soda lime glasses are heated at 350 °C on deposition time of 10, 15, 20 and 25 minutes. NH4F was doped at a ratio of 2 wt% in the SnCl4 precursor and methanol solvent. The results revealed that longer deposition times created decreased the electrical resistivity and optical transmittance of FTO layers. The highest optical transmittance was 84.808% and the lowest resistivity was 4.01×10−5 Ω.cm, obtained from FTO glass subjected to a 15-minute deposition time at deposition temperature of 350 °C. This is accordance to the TCO conductive glass requirements fo...

The effect of substrate heating temperature upon spray pyrolysis process on the morphological and functional properties of fluorine tin oxide conducting glass

Transparent conductive oxide (TCO) is one of the main components in the dye sensitized solar cell (DSSC), a device which is developed as one of renewable energy sources that has high potential to substitute fossil fuel. Among all TCO glasses, fluorine-doped tin oxide (FTO) has the biggest potential to be developed. The purpose of this research is aimed at finding an optimum substrate temperature during spray pyrolysis process in order to obtain FTO substrates with the desired characteristics. For this purpose, soda lime glasses were deposited with a mixture of tin and fluorine doping precursors using a special modified ultrasonic nebulizer with a variation in substrate heating temperature of 250, 300, 350, 400, and 450°C. All the fabricated samples were characterized by using x-ray diffraction (XRD), UV-Vis spectrometry, scanning electron microscope (SEM), and digital multimeter. On the basis of investigation, the best result was obtained in the substrate heated at 300 °C, providing an electrical resistan...

Calcium extraction from brine water and seawater using oxalic acid

Calcium can be extracted not only from rocks but also from natural liquor such as seawater and brine water. In order to extract the calcium from seawater and brine water, oxalic acid was used in this research. Effect of variations of the volume of the oxalic acid at a constant concentration in seawater and brine water to produce calcium was investigated. The concentration of oxalic acid was 100 g/l and the variations of its volume were 2 ml, 4 ml, 6 ml, 8 ml, 10 ml, 20 ml, 30 ml, 40 ml, and 50 ml. The used seawater and brine water were firstly evaporated from 100 ml into 50 ml and then the oxalic acid was added into them with mixing to produce the calcium precipitates. The precipitates were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) and the filtrates were analyzed by inductively coupled plasma-optical emission spectrometry (ICP-OES). The SEM analysis showed that the precipitates from brine water were consisted of only calcium compound while from seawater sodium one was also...

Controlling the Nanostructural Characteristics of TiO2 Nanoparticles Derived from Ilmenite Mineral of Bangka Island through Sulfuric Acid Route

The ilmenite mineral (FeO.TiO2) from Bangka Island-Indonesia is an important source for synthesizing TiO2 nanoparticles. However, the process is rather difficult since this mineral still contains many impurities and minor elements. Therefore, controlling the synthesizing route parameters is essential for obtaining the desired TiO2 nanoparticle characteristics. In the current work, we proposed a modified process involving the use of sulfuric acid through sol-gel method to provide titanyl sulfate (TiOSO4) solution as the inorganic precursor. For investigation purposes, several parameters were varied including volume ratio of water and titanyl sulfate, addition of iron powder (seeding) and dextrin coagulant, calcination time and temperature. The results showed that TiO2 nanoparticles can be succesfully synthesized using TiOSO4 precursor derived from Bangka ilmenite. Under all processing conditions, the resulting TiO2 nanoparticles have sphere-like shape and were indexed as the anatase TiO2 phase. The results also showed that the average particle size was reduce from 96 188 nm to 32 40 nm when the volume ratio of water and titanylsulfate was increased from 3:1 to 6:1. The addition of iron powder as seeding has improved the purity of TiO2 to ~ 95.01 wt%, in comparison to that of without seeding, which is ~92.78 wt%.

Sulfuric Acid Leaching of Bangka Indonesia Ilmenite Ore and Ilmenite Decomposed by NaOH

lmenite (FeO.TiO2) ore from Bangka island-Indonesia is a potential raw material for synthesizing titanium dioxide (TiO2), which can be used further as pigmen and photocatalyst. The fabrication of TiO2 particles from ilmenite can be carried out through the solvent extraction using sulfuric acid route. Therefore, the solubility of the ilmenite ore in sulfuric acid environment is one of the key factors to obtain the desired TiO2 particles. The current research is aimed at comparing the solubility of pristine Bangka ilmenite ore with that of precedingly decomposed by sodium hidroxide (NaOH) in pressurized and atmospheric reflux reactors. The dissolution of both precursors was carried out in those reactors under various temperatures of 75, 100, 125, 150 and 175°C. The results showed that the optimum dilution was achieved at 150°C. The obtained recovery of ilmenite was 88.8 % for the pressurized reactor and 75.5% for the atmospheric reflux reactor. The solubility of titanium (Ti) element increased steadily to reach a recovery of 68% at 150°C and decreased significantly afterwards. It was also found that the increase of iron (Fe) element solubility was proportional to the increase of processing temperatures.

Preparation, Decomposition and Characterizations of Bangka - Indonesia Ilmenite (FeTiO3) Derived by Hydrothermal Method Using Concentrated NaOH Solution

Ilmenite is an economically important and interesting mineral. It is found as a by-product of tin mining in Bangka Indonesia. This mineral has can be used as the source of making titanium metal, titanium dioxide (TiO2) pigment and material for photo catalysts. However, the synthesis of TiO2 from ilmenite using both sulfate and chloride processes still has faced a major problem to obtain white pigment of high purity and lower operation cost. This is mainly due to Fe2O3 impurity in TiO2 pigment which cannot be easily decomposed. Therefore, this study is aimed at investigating the possibility of using Bangka ilmenite mineral to obtain TiO2 pigments and photocatalysts. For this purpose, , sodium hydroxide (NaOH) was used as decomposition solution via hydrothermal process in a teflon-lined autoclave equipment. The characterization results indicated that Bangka ilmenite contains a significant TiO2 level of more than 30 %, although there still remains some other impurities. Upon decomposition of dissolution using NaOH, was decrease in impurity elements down to 60 %. The decomposition process of ilmenite was optimum at NaOH concentration of 10 M where the ilmenite decomposes to form an intermediate phase of sodium titanate with the morphological shape of fine threads.