An Investigation on the Synthesis of Molybdenum Oxide and Its Silica Nanoparticle Composites for Dye Degradation

oleh: Olfa Kamoun, Abdelaziz Gassoumi, Salah Kouass, Badriyah Alhalaili, Ruxandra Vidu, Najoua Turki-Kamoun

Format: Article
Diterbitkan: MDPI AG 2020-12-01

Deskripsi

The molybdenum oxide (MoO<sub>3</sub>) and MoO<sub>3</sub>@SiO<sub>2</sub> nanoparticles were successfully prepared using the chemical bath deposition (CBD) method. The photocatalytic activities of molybdenum oxide (MoO<sub>3</sub>), SiO<sub>2</sub>, and MoO<sub>3</sub>@SiO<sub>2</sub> nanoparticles composite have shown a synergistic photocatalytic effect of SiO<sub>2</sub> combined with MoO<sub>3</sub>. The first-order degradation rate constants for MoO<sub>3</sub>, SiO<sub>2</sub>, and MoO<sub>3</sub>@SiO<sub>2</sub> nanocomposite were 10.3 × 10<sup>−3</sup> min<sup>−1</sup>, 15.1 × 10<sup>−3</sup> min<sup>−1</sup>, and 16.3 × 10<sup>−3</sup> min<sup>−1</sup>, respectively. The MoO<sub>3</sub>@SiO<sub>2</sub> composite showed degradation efficiencies in the methylene blue solution close to 100% after 60 min of UV irradiation. The X-ray diffraction (XRD) showed that the MoO<sub>3</sub> powder has a hexagonal crystal structure and the silica is the tridymite type of SiO<sub>2</sub>. The crystallite size was about 94 nm, 32 nm, and 125 nm for MoO<sub>3</sub>, silica, and MoO<sub>3</sub>@SiO<sub>2</sub>, respectively, as calculated by the Scherrer equation. The scanning electron microscopy (SEM) images revealed that the MoO<sub>3</sub> powder consisted of a uniform hexagonal structure; the silica showed a rod-like micro-flake morphology and the MoO<sub>3</sub>@SiO<sub>2</sub> composite had the appearance of coral-like structures.