Photocatalytic Properties of Fluorinated Tetraarylantimony Carboxylates

Abstract

Organic dyes are widely used in different kinds of manufacturing. As a result, they become common organic contaminants, and lead to water pollution. Therefore, the search of effective methods for such compound destruction is of interest. One of such methods is the photocatalytic destruction by antimony organic compounds. It has been found out that the incorporation of tetraarylantimony monocarboxylates (Ar₄SbOC(O)R, Ar = Ph, R = C₆F₅ (1), CF₂CF₂CF₃ (2), CF₂Br (3); Ar = p-Tol, R = CF₂CF₃ (4), CF₂CF₂CF₃ (5)) and further irradiation of solutions with UV radiation causes photocatalytic degradation of organic dyes methylene blue (MB) and methyl violet (MV) in their aqueous solutions. The change of concentration of organic dyes could be seen due to change in peak intensity at 554 nm and 665 nm in the UV spectra of MB and MV. Tetraphenylantimony carboxylates 1–3 showed higher photocatalytic activity than tetra(p-tolyl) antimony carboxylates 4, 5. Thus, MB decomposition was 90.5–98.8 %, MV: 97.7–100 % after 60 min irradiation of aqueous solutions containing compounds 1–3. While in the presence of 4, 5, decomposition of MB and MV was 55.1–53.2 % and 71.2–78.7 %, respectively. In both cases, methyl violet was susceptible to more total destruction than methylene blue. The experiments showed the probability of repeatable use of the photocatalysts. After full decay of the pigment, tetraarylantimony carboxylate precipitated by centrifugation, the precipitate was decanted and used for the next cycle. As a result of two photodegradation processes, the mass of tetraarylantimony carboxylates decreased on average by 50 % after washing and drying, but the carboxylates were still effective, which proved the possibility of the photocatalyst repeatable use and their stability.