Visible light-induced photocatalytic activity of modified titanium(iv) oxide with zero-valent bismuth clusters

Abstract

The important challenge in photocatalysis is to find efficient and stable photocatalysts under visible light. Small Bi zero-valent clusters were synthesized on TiO₂-P25 by radiolysis. Photocatalytic tests were conducted under UV, visible and solar light with rhodamine B and phenol as model pollutants. Surface modification of TiO₂ with zero-valent Bi nanoclusters induces high photocatalytic activity under visible light. Very small amounts of Bi (0.5 wt%) can activate titania for photocatalytic applications under visible light. Time resolved microwave conductivity measurements indicate that under visible irradiation Bi nanoclusters inject electrons into the conduction band of TiO₂. These photocatalysts are very stable with cycling.