Photocatalytic activity of composites in an AgBr–Ag2CrO4 system prepared by a grinding method with and without washing

Various composites of photocatalysts in the AgBr–Ag₂CrO₄ system were synthesized via a simple grinding method with and without a washing process. After the starting materials were ground together, the resulting powders showed three phases: AgBr, Ag₂CrO₄, and KNO₃. When these products were washed with deionized water, the KNO₃ did not present in the final product. Under visible light irradiation, the prepared photocatalysts can degrade the rhodamine B and reactive orange dyes solutions. Experimental results showed that the KNO₃ which was the impurity phase in this system did not affect the photocatalytic activities of prepared photocatalysts. The 0.9AgBr–0.1Ag₂CrO₄ composite exhibited the best photocatalytic activity and the photocatalytic enhancement of this compound could be attributed to a charge separation. Investigation of inhibitory activity using scavengers confirmed that photogenerated holes and superoxide anion radicals were the primary reactive species produced during the photocatalytic process.