Preparation of Ag-Coated SiO₂@TiO₂ Core-Shell Nanocomposites and Their Photocatalytic Applications towards Phenol and Methylene Blue Degradation

Abstract

Ag-coated SiO2@TiO2 (Ag-SiO2@TiO2) core-shell nanocomposites were synthesized by a two-step method, which combined hydrothermal process and photodeposition. The morphology, structure, composition, and optical properties of the Ag-coated SiO2@TiO2 nanocomposites were extensively characterized by field-emission scanning microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectra (FT-IR spectra). The anatase TiO2 nanoparticles (5-10 nm) with high surface area were loaded on SiO2 spheres (200-300 nm) in the form of SiO2@TiO2 core-shell nanoparticle with a porous shell of controlled thickness (10–30 nm). Ag nanoparticles of different mass concentrations were photodeposited on SiO2@TiO2 core-shell structure with particle sizes of about 10-20 nm. The results showed that Ag nanoparticles increased the photocatalytic activity of SiO2@TiO2 core-shell nanoparticle improved the degradation of phenol and methylene blue under UV irradiation. The experimental results showed that Ag nanoparticles with mass concentrations of 6% had the highest photocatalytic activity on SiO2@TiO2 core-shell nanoparticles.

Fabrication of FeS2/SiO2 Double Mesoporous Hollow Spheres as an Artificial Peroxidase and Rapid Determination of H2O2 and Glutathione

“…This interaction may be the sharing electrons between O 2p and Fe 3d orbitals. The FeS 2 formation is demonstrated in Figure C at 161.6 and 162.8 eV, and the peak at 168.5 eV is attributable to unsaturated S atoms. , Figure D shows the Si 2p spectrum as Si–O–Si . The O 1s spectrum in Figure E indicates H 2 O and O 2 adsorbed on the FeS 2 /SiO 2 DMHS surface …”

The Effect of Molar Ratios of Ti/Si on Core-Shell SiO2@TiO2 Nanoparticles for Photocatalytic Applications

“…The pore volume of the CSTNs showed the same regularity of the specific surface area, and the CSTNs of Ti/Si = 5 : 1 had the highest pore volume of 0.313 cm 2 g −1 . It can be concluded that the CSTNs with the appropriate molar ratio of Ti/Si had Journal of Nanomaterials significant effects on the samples' specific surface area, pore size, and pore geometry [35].…”

Experimental Study on Injection and Plugging Effect of Core–Shell Polymer Microspheres: Take Bohai Oil Reservoir as an Example

“…At present, solid microspheres can be used in profile control and flooding. The core materials of solid microspheres are SiO 2 , Fe 3 O 4 , TiO 2 , etc., which have no swelling property. − The profile control and flooding effect are not good. Based on the theory of physical chemistry, polymer materials and reservoir engineering, core–shell microspheres with positive core and negative shell was synthesized by means of instrument detection, chemical analysis, and physical simulation.…”