The photocatalytic degradation of azure A was carried out in the presence of semiconductor barium chromate. The rate of degradation of dye was observed using UV-Visible spectrophotometer at regular time intervals. The effect of different variables like pH, concentration of dye, amount of semiconductor and light intensity on rate of dye degradation was observed. The optimum conditions were obtained at pH = 9.0, [Azure A] = 3.0 x 10^-5 M, amount of BaCrO₄ = 0.06 g, light intensity = 50.0 mW/cm². The rate constant obtained was; k = 1.70 x 10^-4 sec^-1. A tentative mechanism for photocatalytic degradation of azure A involving hydroxyl radical as an active oxidizing species has also been proposed.
Keywords: Photocatalytic degradation; Azure A; Barium chromate