Enhancing the photocatalytic activity of TiO2 and TiO2–SiO2 by coupling with graphene–gold nanocomposites

• Published in: Journal of materials science. Materials in electronics Vol. 32; no. 4; pp. 5082 - 5093
• Main Authors: Chinh, Vu Duc, Bavasso, Irene, Di Palma, Luca, Felici, Anna Candida, Scarsella, Marco, Vilardi, Giorgio, Bracciale, Maria Paola, Van, Nguyen Thuy
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-02-2021; Springer Nature B.V
• Subjects: Aqueous solutions; Catalytic activity; Characterization and Evaluation of Materials; Chemistry and Materials Science; Deposition; Field emission microscopy; Fourier transforms; Gold; Graphene; Infrared spectra; Materials Science; Methylene blue; Nanocomposites; Nanoparticles; Optical and Electronic Materials; Photocatalysis; Photocatalysts; Photodegradation; Reduction; Rhodamine; Silicon dioxide; Spectrum analysis; Synthesis; Titanium dioxide
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-021-05242-9

In the present paper, a novel composite Graphene–Gold (Gr–Au)/TiO
2
–SiO
2
photocatalyst was synthesized and tested for the removal of methylene blue and rhodamine B in water solutions. First, Gr–Au nanoparticle composite was synthesized by simultaneous reduction and deposition of Au nanoparticles on Gr surface. The photodegradation of methylene blue and rhodamine B in aqueous solutions was studied using various photocatalysts, including neat TiO
2
–SiO
2
, Gr/TiO
2
–SiO
2
and Gr–Au/TiO
2
–SiO
2
composites. The Gr weight ratio in this research is 2% in the Gr/TiO
2
–SiO
2
composites. Detailed characterization (field emission scanning electron microscope, Raman, Fourier transform infrared spectra and UV–vis absorbance spectroscopy) of such material was conducted. As a result, the uniform deposition of nanometer-sized Au NPs on the graphene sheets was observed. The Gr–Au/TiO
2
–SiO
2
exhibited excellent photocatalytic efficiency because of the reduction of electron–hole recombination. The Gr2%–Au0.1%/TiO
2
–SiO
2
composite had the highest photoactivity.