No abstract

Abstract. Mesoporous pure TiO 2 (M-TiO 2 ) and mesoporous-vanadium-doped TiO 2 (M-V-doped TiO 2 ) were successfully synthesized via a facile and simple reflux technique. The purpose of this research was to study the effect of vanadium dopant on the physicochemical properties of all materials obtained. Characterization of the prepared materials was carried out using X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and N 2 -adsorptiondesorption analysis. The presence of Ti and O elements in M-TiO 2 and of Ti, V and O elements in M-V doped TiO 2 could be detected by SEM-EDS, while the patterns of X-ray diffraction of all the prepared samples had a well-crystalline surface of anatase type. All mesoporous vanadium-doped TiO 2 (M-V-doped TiO 2 ) materials performed in a highly transparent mode in the visible region at 554 nm (E g = 2.24 eV) and 588 nm (E g = 2.12 eV) for 3.3 and 4.9 wt% V doped TiO 2, respectively. The Rietveld refinement method was applied to extract the structural parameters of the M-TiO 2 and M-V-doped TiO 2 using the Fullprof program in the WinPlotr package. The prepared materials were refined in the crystal system and space group of anatase (tetragonal, I4 1 /amd (141)). The vanadium ion was successfully doped into TiO 2 . The isotherm type of M-TiO 2 and 2.3 wt% V doped TiO 2 were of type IV, with a profile of type H2 hysteresis loops, while the 3.3 and 4.9 wt% vanadium-doped TiO 2 reflected isotherm type III. The Brunauer-Emmett-Teller (BET) results showed a significant reduction in surface area due to increased concentrations of vanadium. The highest values of BET-specific surface area, pore volume and average pore size of M-TiO 2 were 46 m 2 /g, 18.45 nm and 0.2572 cm 3 /g respectively.

Undoped titanium dioxide (TiO2) and a series of chromium(III) doped TiO2 (Cr-doped TiOfig. 12) with various %wt Cr atom were prepared by a reflux technique. The undoped TiO2 and Cr-doped TiO2 of 1.1, 3.9, 4.4 %wt Cr atom have been successfully analyzed both qualitative and quantitative analysis of powder X-ray diffraction (XRD) data. The qualitative analysis was carried out with the identification of phases in all samples by comparison with Crystallography Open Database (COD) and International Centre for Diffraction Data (ICDD), while the quantitative phase analysis was calculated by reference intensity ratio (RIR) and whole-pattern fitting (Rietveld analysis) methods. The undoped TiO2 consist of three phases: anatase, rutile, and brookite. In the 1.1 %wt Cr-doped TiO2 are detected presenting two phases: anatase (major) and rutile (minor). In the 3.9 %wt Cr-doped TiO2 andin the 4.4 %wt Cr-doped TiO2 consist of anatase as major phase, while CrO2 and TiO2-II phases can be detected as minor phases. The undoped TiO2 was refined in the phase, crystal system and space group of anatase (tetragonal, I41/amd), rutile (tetragonal, P42/mnm) and brookite (orthorhombic, Pbca), while the 1.1 %wt Cr-doped TiO2 was refined based on anatase (tetragonal, I41/amd), rutile (tetragonal, P42/mnm). Finally, in the 3.9 %wt Cr-doped TiO2 and 4.4 %wt Cr-doped TiO2,respectively were refined in the crystal system and space group of anatase (tetragonal, I41/amd).

<p>Samples of vanadium- and -chromium doped TiO₂-anatas have been conducted antibacterial activity against the bacteria<em> Escherichia coli </em>(<em>E. Coli</em>). The minimum kill concentration (MBC) against the bacteria of <em>E. Coli</em> is determined  by liquid dilution method. The antibacterial activity test of 0; 2.3; 3.3; 4.9% wt. vanadium doped TiO₂-anatas and 0; 1.1; 3.9; 4.4% wt. chromium doped TiO₂-anatas have been performed against bacteria of <em>E. Coli</em> in the absence of light (dark). The test results indicate that the presence of 3.3 and 4.9 in %wt. vanadium-TiO₂-anatas are able to inhibit the growth of bacteria <em>E. Coli</em>, contrary all chromium doped TiO₂-anatas are not able to inhibit the growth of bacteria of <em>E. Coli</em>.</p>

LiCoxMn2-xO4 can serve as one of the main candidates for cathode materials for lithium batteries since they are abundant, low cost and environmentally friendly. This study aims to study the synthesis of LiCoxMn2-xO4 by low temperature solid-state reaction and its microstructure determination. Attention is paid more to the mole ratio of Co/Mn in LiCoxMn2-xO4. The compound was characterized by XRD, SEM-EDX, and BET while the analysis of LiCoxMn2-xO4 microstructure was carried out by Direct Method using winPLOTR package program and Diamond using XRD data. The series of LiCoxMn2-xO4 have well–developed cubic crystal structure with Fd3m phase, and the increase in the dopant does not change its structure. The lattice parameters and cell volumes of LiCoxMn2-xO4 tend to decrease with the increase in x values