Electrodeposited multi-walled carbon nanotubes on Ag-loaded TiO2 nanotubes/Ti plates as a new photocatalyst for dye degradation

Abstract

MWCNTs/Ag/TiO₂NTs plates were synthesized via electrochemical reduction of functionalized multiwalled carbon nanotubes (MWCNTs) on Ag/TiO₂NTs. The loading of silver nanoparticles was carried out by electroless reduction of Ag¹⁺ onto TiO₂ nanotubes previously formed by anodizing titanium. The SEM analysis revealed that MWCNTs were loaded significantly on the as-prepared Ag/TiO₂NTs, where nanoparticles of Ag had grown on the walls of TiO₂NTs. The photocatalytic activity of the synthesized plates was evaluated by the photodegradation of Methyl Orange (MO) dye under UV light irradiation. The results indicated that the MWCNTs/Ag/TiO₂NTs demonstrated improved efficiency for MO photodegradation in comparison with Ag/TiO₂NTs and TiO₂NTs. This is attributed to the efficient separation and transfer of photogenerated electron–hole pairs. The chemical oxygen demand of an MO dye solution as measured at specified time intervals provides a good idea about the degradation of MO.