Experimental study of the visible-light photocatalytic activity of oxygen-deficient TiO2 prepared with Ar/H2 plasma surface treatment

Abstract

Oxygen-deficient TiO2 (TiO2−x) has been proposed as a visible-light-responsive photocatalyst. TiO2−x thin films were prepared by Ar/H2 plasma surface treatment, applying varying levels of microwave input power and processing times. The highest visible light photocatalytic activity was observed when using an input power of 200 W, a plasma processing time of 10 min, and a ratio, conditions that generate an electron temperature of 5.7(±1.0) eV and an electron density of 8.5 × 1010 cm−3. The maximum formaldehyde (HCHO) removal rate of the TiO2−x film was 2.6 times higher than that obtained from a TiO2−xNx film under the same test conditions.