Photocatalytic Reduction and Immobilization of Hexavalent Chromium at Titanium Dioxide in Aqueous Basic Media

The thermodynamic aspects of the photocatalytic reduction of Cr(VI) at are first discussed and contrasted for pH 0 and pH 10 aqueous media. The photocorrosion of is shown to be thermodynamically less favorable in basic media. A scheme for the one‐step removal of Cr(VI) at via its reduction and subsequent immobilization [as ] is demonstrated for pH 10 chromate solutions. Dissolved oxygen is shown to inhibit the reduction of Cr(VI). A preliminary kinetics analysis reveals adherence of the initial rate of Cr(VI) reduction to the simple Langmuir model.