Photocatalytic degradation of dyes by CdS microspheres under near UV and blue LED radiation

• Photocatalytic degradation of dyes by visible LED/CdS microspheres was successful.
• CdS microspheres could be recycled without losing their efficiency.
• Photocorrosion of CdS microspheres was inhibited using glucose as protecting agent.
• Low electrical costs were evaluated for the method under investigation.

Nanostructured CdS microspheres were prepared by hydrothermal synthesis and used as photocatalyst in the degradation of dyes under near UV and blue LED radiation. Nearly complete degradation of methylene blue, phenol red and methyl red was achieved in 3 h. Catalytic performance of the microspheres remained unchanged during five recycling steps. Different modification methods were tested to prevent photocorrosion of the CdS particles. Using glucose as protecting agent gave the most promising results. Furthermore, photocatalysis under LED radiation tested in this study showed quite good energy efficiency, which makes this method economically appealing.