Photocatalytic degradation of organic pollutants with Ag decorated free-standing TiO₂nanotube arrays and interface electrochemical response

Abstract

Decoration of TiO2 by metal nanoparticles allows for the fabrication of a new nanocomposite electrode with enhanced performance in photo-electrochemical applications. In this article, we report a facile way to synthesize free-standing, highly orientated TiO2 nanotube (TiO2-NT) arrays by a new kind of two-step electrochemical anodization method, and an efficient decoration of uniform sized Ag nanoparticles onto the outer and inner surface of TiO2 nanotubes through a wetting-thermal decomposition route. In particular, compared with pure TiO2-NT arrays, the testing of nanoelectrode made with Ag/TiO2-NTs composite arrays presents enhanced efficiency in photocatalytic degradation of methylene blue dye and organic pollutant of pentachlorophenol, and improved electrochemical responses as results of the suppression of electron/hole pairs from recombination and acceleration of surface charge transfer by Ag nanoparticles.