Effects of electromechanical resonance on photocatalytic reduction of the free-hanging graphene oxide sheets

Abstract

In this report we present a simple, low-temperature method which is compatible with standard technology, to achieve graphene-based devices in large quantity. In this approach we take advantage of photocatalytic behavior of TiO2 to achieve photocatalytic reduction of chemically synthesized graphene oxide (GO) sheets. TiO2 nanoparticles have been deposited on GO sheets hanging from Au/SiO2/Si interdigital electrodes to realize TiO2/GO heterostructures. We investigated photocatalytic activity of TiO2 nanoparticles in the presence of UV-illumination, to reduce the GO sheets. Based on the Raman spectroscopy, the photocatalytic activity of TiO2 nanoparticles resulted in a decrease in the number of C–O bonds. Electrical measurements show that graphene sheets with the controlled electrical conductivity were obtained, so that higher illumination time led to higher conductivity and better reduction of GO sheets. Also, strain-induced photocatalytic reduction of the GO sheets has been investigated by their electrical characteristics. It has been shown for the first time that the electromechanical-induced strain enhances the photocatalytic behavior of the fabricated TiO2/GO heterostructure significantly.