Electrochemical sensing and photocatalysis using Ag-TiO₂ microwires

Abstract

Anatase Ag-TiO₂ microwires with high sensitivity and photocatalytic activity were synthesized via polyol synthesis route followed by a simple surface modification and chemical reduction approach for attachment of silver. The superior performance of the Ag-TiO₂ composite microwires is attributed to improved surface reactivity, mass transport and catalytic property as a result of wiring the TiO₂ surface with Ag nanoparticles. Compared to the TiO₂microwires, Ag-TiO₂ microwires exhibited three times higher sensitivity in the detection of cationic dye such as methylene blue. Photocatalytic degradation efficiency was also found to be significantly enhanced at constant illumination protocols and observation times. The improved performance is attributed to the formation of a Schottky barrier between TiO₂ and Ag nanoparticles leading to a fast transport of photogenerated electrons to the Ag nanoparticles.