تحضير ودراسة المتراكب النانوي (MoO3/TiO2) وتطبيقه في الازالة اللونية

Preparation and Study of MoO3/TiO2 Nano-composite and Application in Decolorization

Summary:

        This project consists of three main parts: Part one includes the preparation of molybdenum trioxide as α-MoO3 nanobelts using a hydrothermal method. In this way, the dimensions of the prepared material were controlled by the reaction between sodium molybdate dihydrate as a precursor and dilution HCl.

The α-MoO3/TiO2 nanocomposite was prepared in a w/w ratio of 0.25 (α-MoO3): 9.75 (TiO2) using  ultrasonic waves technique, which is fast, simple, and regarded as a friendly environment method. Part two deals with the characterization of prepared α-MoO3, α-MoO3/TiO2 nanocomposite, and commercial TiO2. The XRD analysis conformed that the α-MoO3 and its nanocomposite with TiO2 are successfully prepared based on appeared the strong intensity peaks at miller indicates (020), (040), and (060). SEM analysis indicated the shape of prepared α-MoO3 and found to be nanobelts, while the shapes of TiO2 and α-MoO3/TiO2 nanocomposite are semi-spherical and semi-spherical agglomerate respectively . The FT-IR spectra were confirmed to synthesis the α-MoO3 and α-MoO3/TiO2 nanocomposite with appeared the peaks of metal-oxygen bonds at 675 cm-1 for Ti-O and at 559 cm-1 for Mo-O. The calculated band gaps (Bg) by the Tauc equation detected that all the catalysts are a photocatalyst, and demonstrate the commercial TiO2 and the nanocomposite are having an indirect band gap, but the α-MoO3 is having a direct band gap with 3 e V, 2.95 e V, and 2.8 eV respectively. Part three focuses on the ability and tests their efficiency of the α-MoO3, TiO2, and its nanocomposite α-MoO3/TiO2 on the decolorization of chlorazol black BH dye as a studied model. The influence of different parameters on photo-decolorization of chlorazol black BH dye by using the commercial TiO2, prepared α-MoO3/TiO2 nanocomposite was illustrated. The parameters include the dose of photocatalysts, temperature, and initial pH of the solution. The thermodynamic parameters were calculated using the Arrhenius equation, the Eyring-Polanyi equation, and the Gibbs equation proved this photoreaction is an exothermic, less random, and nonspontaneous reaction using TiO2, while with using α-MoO3/TiO2 nanocomposite is endothermic, less random, and nonspontaneous reaction. The activity of photodecolorization for chlorazol black BH dye obtained to be maximum with the using the prepared α-MoO3/TiO2 nanocomposite that leads to increase the acidity of α-MoO3 after incorporated the α-MoO3 in the crystal lattice of TiO2. This photoreaction follows the pseudo-first-order kinetics dependent on chlorazol black BH dye.