Surface characterization and photocatalytic reactivity of innovative Ti/TiO₂and Ti/Pt-TiO₂mesh photoelectrodes

Abstract

Novel Ti/TiO₂and Ti/Pt–TiO₂mesh photoelectrodes were produced by anodizing titanium mesh in H₂SO₄solution. Their structural and surface morphology were examined by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The analytical results indicated that the crystal structure, morphology and pore size were affected significantly by the voltage and current density applied in anodization and the percentage platinum content. The results of XPS measurement showed that the binding energy of O 1s and Ti 2p increased slightly owing to platinumdeposit ion (Pt⁰,Pt²⁺ and Pt⁴⁺) onto the TiO₂surface. The photoelectrocatalytic (PEC) oxidation of methyl orange in aqueous solution using the Ti/TiO₂and Ti/Pt–TiO₂meshes was investigated. The experimental results demonstrated that Ti/TiO₂mesh prepared at 160 V and 110 mA cm⁻² achieved the best PEC oxidation. The efficiency of PEC oxidation could be further enhanced by applying an electrical bias between the working electrode and counter electrode. An optimal electrical bias voltage was found to be 0.6 V, while an optimal platinum content was 3.37%.