Study of YVO4 as a photocatalyst: Correlation between synthetic route and ecotoxicity.

Yttrium orthovanadate (YVO 4 ) powders were synthesized by two different routes: the combustion route (C sample), and the hydrothermal route (H samples). In all samples, oxygen vacancies were observed by Raman, UV–vis diffuse reflectance and photoluminescence (PL) spectroscopy; however they were more significant in C sample. Photocatalytic discoloration of Rhodamine B solutions ranged from 40 to 64% and C and H4 samples presented the highest efficiencies. Although both samples showed similar photocatalytic efficiency, C sample is 11 times more efficient in producing reactive oxygen species than H4 sample, and an interesting effect of the treated solutions was observed in the Fish Embryotoxicity Test, carried out in D. rerio . The C-treated solution was more toxic than the untreated solution, while the H4-treated solution did not show toxicity enhancement. C-treated solution caused a significant mortality of D. rerio embryos beginning at the 4th day of exposure and reached total mortality at the 6th day. Thus, the synthetic route employed in the preparation of C and H4 samples leads to different toxic effects in the treated solutions. These results pointed out that microstructural characteristics and synthetic parameters are not only important for obtaining highly active materials, but they also impact on the toxicity of the effluents. [ABSTRACT FROM AUTHOR]