Enhancement of photocatalytic degradation by combination of light illumination and bias voltages toward anti-virus coating applications

In this work, oxidative decomposition reaction of organic reactant on TiO₂ surface was investigated under soaking conditions by combination of applying voltages and light illumination. Since carriers of TiO₂ thin films originate from point defects such as oxygen vacancies, reactive carriers possibly exist on TiO₂ thin films even under room light illuminating condition and dark condition. Thus, enhancement degrees of photooxidation by applying bias voltages onto TiO₂ thin films were compared under dark, visible light illumination and UV illumination conditions. Bias voltages were applied to localize the photogenerated carriers at the vicinity of TiO₂ surface for enhancing photooxidation. Sol-gel derived TiO₂ thin films with porous nano structure exhibited a stronger oxidative decomposition reaction than sputter-deposited TiO₂ thin films.