In this work we propose Eu<sup>3+</sup>-doped YVO<inf>4</inf> as a model compound of a multimodal photoenergy converter that shows photoluminescence and photocatalytic activity and discuss the relation between these two photoenergy conversion modes. YVO<inf>4</inf>:Eu<sup>3+</sup> nanoparticles with different Eu<sup>3+</sup> concentrations and distributions were prepared by coprecipitation and ion exchange methods. The obtained samples consisted of elliptical nanoparticles of 20-25 nm in mean size, irrespective of the Eu<sup>3+</sup> concentration and distribution. The nanoparticles showed two photoenergy converting functions under UV irradiation: (i) Red photoluminescence corresponding to a 4f → 4f transition of Eu<sup>3+</sup> and (ii) photocatalytic decomposition of methyl orange. Increase in the Eu<sup>3+</sup> concentration increased the photoluminescence quantum yield but decreased the photocatalytic activity. Localizing Eu<sup>3+</sup> ions at the particle surface increased the photocatalytic activity but decreased the photoluminescence quantum yield. These results imply a competitive relation between photoluminescence and photocatalytic activity for the compositional range used in this work.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films