Synthesis and Characterization of In₂O₃-ZnO Nanostructures via the Precipitation Method ^†

Nanocomposites, through their synergetic interaction between components, lead to integrated compatible structures, which opens new horizons for their application as materials in the realization of sensors. In₂O₃-ZnO, nanostructures exhibit a large bandgap, high optical transparency, electrical conductivity, uniform surface, chemical and thermal stability in different environments, and excellent photoelectrocatalytic performance, which can be attributed to the enhanced absorption of photons in the visible range and the effective separation of charge carriers at the interface, which makes them interesting for biomedical applications. To obtain these types of materials, the synthesis methods play a fundamental role, influencing the characteristics of the individual components, the bonds formed between them, size, degree of distribution, interface interactions, performance criteria, etc. In the present paper, for the synthesis of In₂O₃-ZnO composites, the wet chemical method was used, followed by the steps of maturation, aging, and filtration, drying, and, finally, heat-treatment steps. To obtain the desired properties of the synthesized composites, it was ensured that the process parameters (reaction temperature, rate of addition of reactants, concentration, etc.) were precisely controlled, because they have a direct effect on the size and morphology of the particles. Methods for investigating the structure, morphology, and wetting capacity are consistent with the physical–chemical properties. Thus, using SEM, equipped with EDX, the morphology and size of the particles were investigated, and microanalysis of the chemical composition of the composite structures was carried out. FTIR spectroscopy was used for the structural characterization of the samples, indicating the presence of the characteristic In-O and Zn-O bonds, and by means of X-ray diffraction structures of high crystallinity and purity. The study of the wetting capacity highlighted composites with a strong hydrophilic character.