تحضير وفعالية التحفيز الضوئي ل TiO النانوي المدعم بالعناصر المشتركة في مذيبات مختلفة ودراسته نظريا == Synthesis and photocatalytic Activity of Co - doped TiO2 Nanoparticles in Different Solvents and its Theoretical study
Author name:
دينا عبد الكريم علي
Supervisor name:
رمزي رشيد علي العاني | حسين اسماعيل عبد الله
General topic:
Chemistry
Specific topic:
Physical Chemistry
Degree:
Doctorate
University:
Mustansiriyah University - College Of Science
Language:
English
University location:
Baghdad
First pages:
25T1753 - p.pdf
Abstract:
The nano particles Titanium dioxide (TiO2) were prepared using chemical modifiers and dopants. Three carboxylic acids were used as a chelating agents : Malonic acid (Mal.) (COOH CH2 COOH), adipic acid (Ad.) (COOH(CH2)4COOH) and Aconitic acid (Aco.) (COOHCH2CH=C(COOH)2) in three different mol ratios (2/1, 1/1 and 1/2 of TiCl4 /acid) to give three complexes : 1. [Ti2(Mal)(OH)6(EtOH)4] (EtOH)22. [Ti2(Ad)(OH)6(H2O)2]H2O3. [Ti3(ACO)(OH)a(EtOH)6](EtOH)2These complexes characterized by FTIR and flame atomic absorption to suggest the type of binding between Ti+4 and the carboxylate and predict the formula structures of complexes.The three complexes studied theoretically using semi - empirical method of hyper chem. 8.0 program (PM3) to : Optimized the structural geometries, The heat of formation (ΔH○f), binding energy (ΔEb)and total energy (ΔET) for the three complexes were calculated at 298 K○. The bond length, vibration spectra and electronic spectra for the three complexes were estimated and then compared with the experimental values. The theoretical results agreed with those found experimentally.After calcinations at three deferent temperature (500,700 and 900)ºC the observed TiO2 samples were characterized by XRD to determined the anatase phase ratio in the samples . At 500 o C All samples with mole ration 1 : 1 (TiCl4 : Acid) give 100% anatase phase . At 700ºC 93% retention of anatase for (Ti1 : Ad1) sample,88% anetase retention for (Ti1 : Mal1) sample and 95% anatase retention for (Ti1 : ACO2) are obtained. At 900ºC only one samples of Ti : ACO give 40% anatase retention but the other samples have very low percentage of anatase.The (SEM) and (AFM) were used to study the morphology of the samples and determined the particles size for the samples calsined at 500 ºC.The minimum average diameter obtained for (Ti : Ad1) sample calcined (70nm) and all other samples below 100 nm. The photocatlytic studied of these samples calcined at 500,700and 900 ºC was examined for degradation of para - nitro phenol under Uv - visible light and give a good removed ratio and rate of degradation especially for the samples that have small ratio of rutile.The optimum Adipic acid, tetra chloride mole ratio (TiCl4 : Adipic 1 : 1)were used to prepare TiO2 singly doped and doubly doped with Pt4+, Au3+, S6+and Se4+ ions. These samples prepared and a calcined at 500ºC to give (Pt - TiO2), (Au - TiO2), (S - TiO2) and (Se - TiO2) samples with mole ratio 1% of ( ) and prepared Co - doped TiO2 with (Pt,Au - TiO2),(Pt,S - TiO2),(Pt,Se - TiO2), (Au,S - TiO2),(Au,Se - TiO2) and (S - Se - TiO2) in two mole ratio (1/100 and 2/100 of ) these samples characterized by Uv - visible adsorption spectroscopy to determine the band gab of the doped - TiO2 and Co - doped TiO2 sample. The X.R.D. used to determine the anatase ratio in the doped and Co - doped samples and all samples give 100% anatase accept the (Au - TiO2), (Au,Se - TiO2) and (Pt,Au - TiO2) samples which contain 15% rutile.The AFM and SEM were used to study the morphology of the doped and Co - doped samples to determine the particle size. The samples Pt - TiO2 give particles similar to size similar to that of Ti1 : Ad1 samples but the other samples give larger particles size .The photocatalytic degradation of P - Np under visible irradiation using the doped and Co - doped samples .The results show good removal ratio more than the undoped sample.
