Effect of the Photonic Band Gap Position on the Photocatalytic Activity of Anodic Titanium Oxide Photonic Crystals

The slowing down of the group velocity of light at the edges of the photonic band gap is one of the important optical effects observed in photonic crystals. The "slow light" effect is used in photocatalysis to enhance the photocatalytic activity of semiconductors. In this work, anatase photonic crystals with different spectral positions of the photonic band gap (390-1283 nm, measured in water) were obtained. It has been shown that the maximum photocatalytic activity in the photodegradation of methylene blue is exhibited by photonic crystals with the position of one of the photonic band gaps near the intrinsic absorption edge of the semiconductor (410 nm). At the same time, the photocatalytic activity of an anatase photonic crystal increases by 30% when the photonic band gap of the third rather than the first order is located near the absorption edge of the semiconductor.