Simple sonochemical synthesis of Ho 2 O 3 -SiO 2 nanocomposites as an effective photocatalyst for degradation and removal of organic contaminant.

In this work, highly photocatalytically active Ho2 O3 -SiO2 nanocomposites have been designed and applied for decomposition of methylene blue pollutant. Ho2 O3 -SiO2 nanocomposites have been produced by new, quick and facile sonochemical process with the aid of tetramethylethylenediamine as a novel basic agent for the first time. The effect of the kind of basic agent, ultrasonic time and dosage of Ho source on the grain size, photocatalytic behavior and shape of the Ho2 O3 -SiO2 nanocomposites have been evaluated for optimization the production condition. FESEM, EDX, FT-IR, DRS, XRD and TEM have been applied to characterize the as-produced Ho2 O3 -SiO2 nanocomposites. Use of the as-produced Ho2 O3 -SiO2 nanocomposites as photocatalyst via destruction of methylene blue pollutant under UV illumination has been compared. It was observed that SiO2 has notable impact on catalytic activity of holmium oxide photocatalyst for destruction. Introducing of SiO2 to holmium oxide can enhance destruction efficiency of holmium oxide to methylene blue pollutant under ultraviolet light.