The Use of Polysaccharide Matrices as a Basis for the Formation of Tellurium Nanoparticles with Different Morphologies.

The widening of possible areas of practical uses for zero-valent tellurium nanoparticles (TeNPs) from biomedicine to optoelectronic and thermoelectric applications determines the actuality of the development of simple and affordable methods for their preparation. Among the existing variety of approaches to the synthesis of TeNPs, special attention should be paid to chemical methods, and especially to "green" approaches, which are based on the use of precursors of tellurium in their powder bulk form and natural galactose-containing polysaccharides-arabinogalactan (Ar-Gal), galactomannan-(GM-dP) and κ-carrageenan (κ-CG) acting as ligands stabilizing the surface of the TeNPs. The use of basic-reduction system "NH HO-NaOH" for preliminary activation of bulk-Te and Ar-Gal, GM-dP and κ-CG allowed us to obtain in aqueous medium a number of stable nanocomposites consisting of TeNPs stabilized by the polysaccharides' macromolecules. By varying the precursor ratio, different morphologies of nanoparticles were obtained, ranging from spheres at a polysaccharide/Te ratio of 100:1 to rice-like at a 10:1 ratio. The type (branched, combed, or linear sulfated) of polysaccharide and its molecular weight value determined the size of the nanoparticles. Thus, the galactose-containing polysaccharides that were selected for this study may be promising renewable materials for the production of water-soluble TeNPs with different morphology on this basis.