Low-cost synthesis of titanium dioxide nanotubes/reduced graphene oxide heterostructure for pH sensor applications

In this work, we deposit Graphene Oxide (GO) films on Titanium Dioxide nanotubes (TiO2NTs); electrochemical characterization of this system shows that this structure has potential applications as a pH sensor. TiO2NTs were obtained by electrochemical anodization technique, the GO was fabricated by modified Hummer's method, and deposited by dip coating technique, at room temperature. The thermally treated TiO2NTs/GO structure shows a reduction of the GO deposited film. The samples were characterized by Raman spectroscopy, X-ray Photoelectron Spectroscopy, and Scanning Electron Microscopy. Depending on the GO oxidation time and thermal treatment, we observe a uniform reduced GO film on the TiO2NTs. A pH electrode characterization shows a linear response of the TiO2NTs/GO of 57 mV/pH with non-hysteresis effect. •Titanium Dioxide Nanotubes (TiO2 – NTs) were fabricated by anodic oxidation and Graphene Oxide (GO) were obtained by Hummers method (low costs and simple methods).•Higher deposition graphene oxide areas on TiO2 nanotubes were obtained for GO with high oxidation rate.•After annealing treatment amorphous TiO2 - NTs/ GO system were converted in anatase TiO2-NTs/ reduced graphene oxide (rGO).•pH electrode with a more linear response, high sensitivity value and non-hysteresis effect were obtained for TiO2 - NTs/ GO system when compared with TiO2-NTs system.