Photocatalytic UV-Induced Approach for Discoloration of Bromocresol Purple, Bromothymol Blue Dyes and Their Mixture Using NixFe3-xO4/ Fe2O3/AC Composites

The nickel ferrite-activated carbon samples NiFe2O4/Activated carbon and NixFe3-xO4/Fe2O3/AC, x = 0.25; 0.5 obtained by co-precipitation followed by thermal treatment in inert atmosphere, were studied for discoloration of Bromocresol Purple (BCP), Bromothymol Blue (BTB) dyes and their mixture as model contaminants under UV-A light. The prepared materials were investigated by XPS, PXRD and XRF analysis, FT-IR spectroscopy, SEM, EDX, BET method and TG analysis. The photocatalyst with composition NixFe3-xO4-AC, x = 1 has demonstrated the highest photocatalytic activity towards discoloration of the BTB in comparison with the others tested materials NixFe3-xO4/Fe2O3/AC, x = 0.25; 0.5. These results can be explained with the smaller particle sizes, the mesoporous structure, the higher degree of crystallinity and higher content of hydroxyl groups. This study proved that the obtained nickel ferrite-activated carbon materials are suitable as photocatalysts for discoloration of the BTB dye. They have demonstrated also relatively high adsorption ability towards BCP dye.