Scaling up anodic TiO2 nanotube layers for gas phase photocatalysis

Abstract In this work, for the first time, an anodic TiO 2 nanotube layer of large area (~50 cm 2 ) was used for photocatalysis in the gaseous phase. Hexane was chosen as model pollutant. The nanotube layer showed superior efficiency compared to a reference TiO 2 layer of the same thickness composed of immobilized P25 nanoparticles. An additional TiO 2 coating of the nanotube layer produced by atomic layer deposition did not enhance the photocatalytic degradation of hexane due to a decrease in the active surface area, in contrast to liquid state photocatalysis under applied external potential.