One-step electrochemical synthesis and visible-light photocatalytic activities of bismuth titanate coatings: Effect of voltage

Abstract Nanostructured Bi 12 TiO 20 coatings with superior photocatalytic property were controllably fabricated on bismuth substrates by one-step electrochemical method in the alkali electrolytes. It was found that the high voltage spark, which initiated the transformation of Bi 2 O 3 precursor generated at low voltage to sillenite type Bi 12 TiO 20 , dominated the formation of bismuth titanate coating. Varying the deposition voltage can effectively tailor the crystallinity, morphology and optical property of the coatings. Bi 12 TiO 20 coating consisting of spherical particles of ca. 30 nm in size and micropores of ca. 100 nm in diameter was obtained at voltage 80 V, exhibiting enhanced visible spectrum absorption and higher photocatalytic ability compared to pure TiO 2 films prepared with similar electrochemical method.