Enhancement of the photocatalytic efficiency of ZnO utilizing luminescent Y2O3 particles

Abstract

This study explored the superior photocatalytic performance of the nanoscale zinc oxide-yttrium oxide (ZnO-Y _2 O _3 ) based composite over ZnO nanoparticles (NPs). We investigated this by following the photocatalytic degradation efficiency of methylene blue (MB). The sol–gel synthesized Y _2 O _3 and ZnO NPs were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The spectral behaviour and photocatalytic efficiency of the proposed composite were investigated by UV–vis spectrophotometry, steady-state and time-resolved photoluminescence (PL) measurements, respectively. The results indicated the successful formation of Y _2 O _3 and ZnO nanoparticles with desirable structural properties. The photocatalytic degradation efficiency of the MB solution was evaluated for different concentrations of the counterparts of the ZnO-Y _2 O _3 composite. In particular, the ZnO-5Y _2 O _3 -based composite showed superior photocatalytic activity after 150 min of UV irradiation, achieving 98.4% degradation of the MB solution compared to the 77% degradation achieved by pure ZnO. Although Y _2 O _3 alone does not exhibit photocatalytic activity, its combination with ZnO significantly enhances the photocatalytic performance of ZnO. This improvement was attributed to the luminescence properties of Y _2 O _3 . By elucidating this unique mechanism, the performance of photocatalytic materials can be significantly enhanced. In our study, the improvement of the photodegradation rate constant (k _app ) of ZnO from 0.009 min ^−1 to 0.0242 min ^−1 demonstrated the promising photocatalytic efficiency of the ZnO-5Y _2 O _3 based composite, opening up exciting possibilities for further applications in environmental remediation and other fields.

Keywords

• photocatalysis
• photoluminescence
• sol-gel processes
• zinc oxide
• yttrium oxide