Visible-light-responsive photocatalyst based on ZnO/CdS nanocomposite for photodegradation of reactive red azo dye and ofloxacin antibiotic

Fabrication of ZnO/CdS nanocomposite with addition of sodium dodecyl sulphate (SDS) has been demonstrated. The ZnO photocatalyst was synthesized first by precipitation route and then the CdS photocatalyst was decorated on the surface of the ZnO via a hydrothermal technique. The PL intensity of the ZnO/CdS nanocomposite was lower than that obtained from ZnO. This indicates lower electron-hole recombination rate implying the improvement of photoactivity. The composite showed efficiency of 80% and 73% toward photodegradation of reactive red 141 (RR141) azo dye and ofloxacin (OFL) antibiotic, respectively. This is attributed to its high specific surface area together with suppression of charge carrier recombination. The efficiency of OFL degradation also reached 90% under solar light. The structural stability of the photocatalyst after three runs has been confirmed. The photogenerated hole played a crucial role in photodegradation of OFL antibiotic. The prepared ZnO/CdS photocatalyst shows a promising potential for environmental protection.

Automated summary

In this study, a ZnO/CdS nanocomposite was successfully synthesized with high efficiency in degrading reactive red 141 azo dye and ofloxacin antibiotic. The composite showed great potential for environmental protection.