Effect of external bias voltage and coating thickness on the photocatalytic activity of thermal sprayed TiO2 coating

TiO2 coatings of different thickness were prepared by a thermal spray process. It was found that the external bias applied to the as-sprayed TiO2 coating could significantly improve its photocatalytic performance, which was characterized by decomposition of methylene blue (MB) solution. The decomposition efficiency increased with increasing external bias voltage. However, for voltage greater than 15 V, the decomposition efficiency remained constant. The TiO2 coating with a thickness of 6 μm showed the best photocatalytic performance under an external bias voltage of 15 V.