Recycled W and Mo co-doped BiVO4@alumina foam ceramic photocatalyst with high reusability for RhB degradation

The long-term stability and reuse potential of the photocatalyst are of great concern for the degradation of organic pollutants in wastewater. A recycled photocatalyst with high reusability was synthesized by immobilizing BiVO 4 nanoparticles on alumina foam ceramic (BiVO@AFC) via a convenient dip-coating followed by calcination method. BiVO@AFC show stable photocatalytic activity for Rhodamine B (RhB) degradation over 90 cycles of experiments (180 h), requiring only 4 times of regeneration treatments. The regeneration is simple and economical, washing the photocatalyst with ultrapure water and dried it at 55 °C. Each regeneration could restore the RhB degradation rate to above 85%. Characterizations confirmed the stability of the materials in optical absorption and chemical properties. The dual doping of W and Mo within BiVO 4 (3 W-2Mo,BiVO@AFC) exhibits a synergistic effect, significantly enhancing photocatalytic performance and stability. The co-doping also can suppress the loss in specific surface area and pore volume of BiVO@AFC originated from the normal wear and tear during the photocatalytic process. As a result of that, the RhB degradation rate of 3 W-2Mo:BiVO@AFC remained above 80% over 90 cycles of experiments (180 h) requiring 4 times of regeneration. And the RhB degradation rate can be restored to above 94% by the same regeneration with BiVO@AFC. Photogenerated hole (h + ) plays a major role in removing RhB in this case. While the dual doping of W and Mo is in favour of generating more ·OH and ·O₂ − radicals for degradation by promoting photocharges transfer and separation. These make it a promising candidate for large-scale applications for wastewater treatment.