Photoelectrocatalytic Degradation of Organics in Water Using TiO2 Nanotubes

The photoelectrocatalytic behavior of anodically formed titanium dioxide (TiO₂) nanotubes annealed in various atmospheres was characterized. A point-of-use device containing these titanium nanotube arrays (TNA) has previously shown to disinfect water containing E-coli and this work further expands the application to organic contaminants in water.  Inactivation occurs in the presence of sunlight and an applied voltage bias.  The device is also capable of degrading organic chemicals such as phenol. Many industrial waste streams include phenol which is a common hazardous water contaminant.  Degradation of .25mM phenol is apparent after a 5 min residence time. Addition of 2 mM NaCl solution significantly increased the degradation as characterized by UV-Vis, HPLC, and GC-MS. Data showing adsorption of organic species, radical kinetics, and the oxidation reduction potential of the device will be presented.