Photocatalytic deposition of bismuth(III) ions onto TiO2 powder

Abstract

Photochemical reduction of Bi^III on illuminated TiO₂ suspensions has been investigated. The photoreduction leads to the formation of metallic Bi on TiO₂. Adsorption of Bi^III species in the dark was examined. The adsorption parameters were determined using the classical Langmuir adsorption isotherm. The photocatalytic deposition rate was determined under various experimental conditions, such as pH, dissolved oxygen and Bi^III initial concentration. The effect of alcohols as hole-scavengers was also investigated. It was found that addition of hole-scavengers increases the efficiency of the photocatalytic deposition process, by impeding recombination of holes and electrons on the catalyst's surface.