Iron oxide nanocatalyst with titanium and silver nanoparticles: Synthesis, characterization and photocatalytic activity on the degradation of Rhodamine B dye.

Nowadays, there is a growing concern about the environmental impacts of colored wastewater. Thus, the present work aims the synthesis, characterization and determination of photocatalytic activity of iron oxide (FeO) nanocatalyst, evaluating the effect of hybridization with titanium (TiNPs-FeO) and silver (AgNPs-FeO) nanoparticles, on the degradation of Rhodamine B dye (RhB). Nanocatalysts were characterized by XRD, SEM, TEM, FTIR, N porosimetry (BET/BJH method), zeta potential and DRS. Photocatalytic tests were performed in a slurry reactor, with the nanocatalyst in suspension, using RhB as a target molecule, under ultraviolet (UV) and visible radiation. Therefore, the photocatalytic activity of the nanocatalysts (non-doped and hybridized) was evaluated in these ideal conditions, where the AgNPs-FeO sample showed the best photocatalytic activity with a degradation of 94.1% (k = 0.0222  min, under UV) and 58.36% (k = 0.007  min, under visible), while under the same conditions, the TiO-P25 commercial catalyst showed a degradation of 61.5% (k = 0.0078  min) and 44.5% (k = 0.0044  min), respectively. According with the ideal conditions determined, reusability of the AgNPs-FeO nanocatalyst was measured, showing a short reduction (about 8%) of its photocatalytic activity after 5 cycles. Thus, the FeO nanocatalyst can be considered a promising catalyst in the heterogeneous photocatalysis for application in the degradation of organic dyes in aqueous solution.