A novel nanocomposite (NC) based on magnetite nanoparticles (Fe₃O₄-NPs) immobilized on the surface of a cationic exchange polymer, C100, using a modification of the co-precipitation method was developed to obtain magnetic NCs for phosphate removal and recovery from water. High-resolution transmission electron microscopy-energy-dispersive spectroscopy, scanning electron microscopy , X-ray diffraction, and inductively coupled plasma optical emission spectrometry were used to characterize the NCs. Continuous adsorption process by the so-called breakthrough curves was used to determine the adsorption capacity of the Fe₃O₄-based NC. The adsorption capacity conditions were studied under different conditions (pH, phosphate concentration, and concentration of nanoparticles). The optimum concentration of iron in the NC for phosphate removal was 23.59 mg_Fe/g_NC. The sorption isotherms of this material were performed at pH 5 and 7. Taking into account the real application of this novel material in real water, the experiments were performed at pH 7, achieving an adsorption capacity higher than 4.9 mg_PO4–P/g_NC. Moreover, Freundlich, Langmuir, and a combination of them fit the experimental data and were used for interpreting the influence of pH on the sorption and the adsorption mechanism for this novel material. Furthermore, regeneration and reusability of the NC were tested, obtaining 97.5% recovery of phosphate for the first cycle, and at least seven cycles of adsorption–desorption were carried out with more than 40% of recovery. Thus, this work described a novel magnetic nanoadsorbent with properties for phosphate recovery in wastewater.

Hybrid core–shell Au/CeO₂ nanoparticles (NPs) dispersed in UiO-66 shaped into microspherical beads are created using the spray-drying continuous-flow method. The combined catalytic properties of nanocrystalline CeO₂ and Au in a single particle and the support and protective function of porous UiO-66 beads make the resulting composites show good performances as catalysts for CO oxidation (T₅₀ = 72 °C; T₁₀₀ = 100 °C) and recyclability.

Synthesis of polyethylene/silica-silver nanocomposites (PE/SiAg) by in situ polymerization with supported and non-supported catalysts was achieved using the Cp₂ZrCl₂/MAO catalytic system. Silica-silver nanoparticles (SiAg) were synthesized via two routes (acidic and basic) and characterized to determine the silver content, morphology, and size. The basic route resulted in particles with a lower concentration of silver and with smaller diameters. The polymerizations of ethylene in the presence of the fillers produced high yields of nanocomposites. The catalyst support in SiAg was efficient, although the percentage of Zr effectively immobilized was very low. Polyethylene melting and crystallization temperatures did not change significantly with the addition of the filler. SEM images showed differences in the morphologies between the supported and non-supported catalysis, and between the acidic and basic conditions for SiAg preparation. Two different tests were performed and showed that the nanocomposites inhibited the proliferation of bacteria in contact with the films.