Influence of the method of formation a nanosized CoFe<sub>2</sub>O<sub>4</sub>/nontronite composite on its structure and properties
The aim of the study was to establish the influence of the method of formation of the CoFe<sub>2</sub>O<sub>4</sub>/nontronite nanocomposite on its structure and properties. Impurity-free nanoparticles of cobalt ferrite CoFe<sub>2</sub>O<sub>4</sub> (XRD), close to spherical in shape, with a predominant particle fraction in the range of 8-20 nm (TEM), were synthesized using the citrate combustion method. The formation of the CoFe<sub>2</sub>O<sub>4</sub>/nontronite nanocomposite was carried out by two methods: mechanical mixing of available precursors followed by annealing and combustion of iron-cobalt citrate with the formation of spinel in the presence of nontronite in the reactor. The CoFe<sub>2</sub>O<sub>4</sub>/nontronite nanocomposite formed by the first method is characterized by the decomposition of natural aluminosilicate aggregates and a higher sorption activity with respect to formaldehyde than the original clay mineral and spinel. The second method of composite formation leads to the formation of coarse-grained silica structures with worse sorption activity in comparison with natural aluminosilicate and CoFe<sub>2</sub>O<sub>4</sub>.