Synthesis, characterization of V2O5 nanoparticles and determination of catalase mimetic activity by new colorimetric method

This paper deals with an advanced colorimetric method used to determine the catalase mimetic activity of V2O5 nanoparticles by measuring the decrease in potassium permanganate concentration in a mixture containing V2O5 and hydrogen peroxide. The experiments were carried out in batch reactor at room temperature for 3 min at wavelength number of 525 nm. Vanadium pentoxide was synthesized by hydrothermal method (reflux) from ammonium metavanadate (NH4VO3) as a precursor and cetyltrimethylammonium bromide as a surfactant. The annealing of the product was carried out for 2 h, at temperatures of 250, 500 and 750 °C. In order to determine the structure and the chemical nature of the nanoparticles prepared, the characterization was carried out by X-ray diffraction and scanning electron microscopic techniques. Atomic force microscopic and thermal gravimetric investigations have shown the decomposition steps of V2O5 at different temperatures. UV–visible spectroscopic technique and Fourier transform spectrometry were used to further characterize the nanoparticles. Advanced colorimetric method was used to study the catalase mimetic activity of the newly synthesized vanadium pentoxide (V2O5) nanoparticles using hydrogen peroxide (H2O2) as substrate. V2O5 nanoparticles resulted in an increase in the catalase mimetic activity with increasing the annealing temperature of the V2O5 nanoparticles. The maximum activity was found at 500 °C, which subsequently decreased with further increase in the annealing temperature.