Immobilised rGO/TiO 2 Nanocomposite for Multi-Cycle Removal of Methylene Blue Dye from an Aqueous Medium.

This work presents the immobilisation of titanium dioxide (TiO₂) nanoparticles (NPs) and reduced graphene oxide (rGO)-TiO₂ nanocomposite on glass sheets for photocatalytic degradation of methylene blue (MB) under different radiation sources such as ultraviolet and simulated solar radiation. The TiO₂ NPs and rGO-TiO₂ nanocomposite were synthesised through a simple hydrothermal method of titanium isopropoxide precursor followed by calcination treatment. Deposition of prepared photocatalysts was performed by spin-coating method. Additionally, ethylene glycol was mixed with the prepared TiO₂ NPs and rGO-TiO₂ nanocomposite to enhance film adhesion on the glass surface. The photocatalytic activity under ultraviolet and simulated solar irradiation was examined. Further, the influence of different water matrices (milli-Q, river, lake, and seawater) and reactive species (h⁺, ^•OH, and e⁻) on the photocatalytic efficiency of the immobilised rGO/TiO₂ nanocomposite was careful assessed. MB dye photocatalytic degradation was found to increase with increasing irradiation time for both irradiation sources. The immobilisation of prepared photocatalysts is very convenient for environment applications, due to easy separation and reusability, and the investigated rGO/TiO₂-coated glass sheets demonstrated high efficiency in removing MB dye from an aqueous medium during five consecutive cycles. [ABSTRACT FROM AUTHOR]