7th World Nano Conference

Biography

Biography: Rodrigo Segura

Abstract

Graphene layers represent a good candidate to develop composed photocatalysts. Due to its high electronic conductivity It can prevent the recombination of the electron-hole pair and act as a doping agent and even extend the range of light absorption of a semiconductor such as the TiO2. In this contribution thin TiO2 layers were grown on few layers graphene (FLG) in order to prepare hybrid photocatalysts with the properties of both materials. FLGs were synthesized by chemical vapor deposition (CVD) at 1000 °C using acetylene as carbon source and copper as substrate. After synthesis the FLGs were transferred to silicon substrates and TiO2 layers were deposited on FLG by decomposition of titanium tetraisopropoxide in a CVD system. The photocatalytic performances of these materials were evaluated by measurements of photocurrent in a 3-electrode cell assembly by using a solar simulator and a potentiostat. The photocurrent results show that the FLG is very electroactive presenting a similar behaviour under both dark and illumination; on the other hand the TiO2 layers grown over silicon show the typical behaviour of a photoactive semiconductor since these samples exhibit a raise in the current with the applied potential only when It is illuminated. The hybrid Si-FLG-TiO2 material present in principle a similar behaviour of Si-FLG but when we made a chronoamperometry alternating dark and light cycles an discounting the dark response It is possible to observe a similar performance than Si-TiO2 sample. Both materials graphene and titanium dioxide have preserved their properties after the assembly. The authors acknowledge the financial support of Fondecyt 1121203.