Synthesis, characterization and investigation of properties of gold nanoparticles

Metal nanoparticles, especially gold nanoparticles (AuNPs) due to their optical, electronic, physicochemical, surface plasmon resonance properties, simple synthesis and functionalization are used in various fields of biomedicine, such as various sensor manufacturing, drug delivery, imaging, photothermal and photodynamic therapy. The properties of AuNPs or NPs of other metals are largely dependent on these nanostructured synthesis methods, so promising, cost-effective and efficient methods for synthesizing metal nanoparticles are being intensively sought to obtain nanostructures with high catalytic activity. The aim of the work – preparation of AuNPs, their characterization and application as anode materials in a direct glucose fuel cell. Simple and economical methods, such as reduction with citrate from an AuNPs colloidal solution, chemical adsorption, microwave synthesis, and galvanic displacement method have been used for the synthesis of AuNPs. Pure AuNPs and AuNPs supported carbon nanocomposites (AuNPs/C) have been synthesized using the chemical adsorption of AuNPs on the surface of carbon powder from a prepared citrate-stabilized AuNPs colloidal solution and microwave synthesis. AuNPs/C nanocomposites prepared by the both methods have been found to have significantly higher electrocatalytic activity for the oxidation of glucose in an alkaline medium compared with that of pure AuNPs catalyst. A method to modify the chemical adsorption synthesis by using halide additives (KCl, KBr, KI) has also been proposed for the preparation of catalysts that have AuNPs with different size and shape. It was found that the oxidation of glucose on those catalysts occurs at more negative electrode potential values, indicating a higher activity of them for glucose oxidation. Catalytically active substances for direct glucose fuel cells - AuNPs modified Co and CoB catalysts have been developed using electroless metal deposition and galvanic displacement methods