Deep Eutectic Solvent-Assisted Hydrothermal Synthesis of Chitosan-Based Nanohybrid Films Functionalized with Silver-Decorated Tungsten Oxide

Abstract

This study presents the fabrication and characterization of chitosan-based nanohybrid films incorporating silver-decorated tungsten oxide (Ct-AgWO3). In this work, deep eutectic solvent-assisted hydrothermal synthesis of WO3 nanoparticles was combined with in situ silver decoration and chitosan reduction to synthesize a nanohybrid film. The effects of the reaction time on the structural, morphological, and functional properties of the nanohybrid films were investigated over time. The resulting nanohybrid film was characterized using UV-Vis spectroscopy, FESEM, EDX, FTIR, XPS, Raman spectroscopy, TGA, and photoluminescence. Morphological analysis revealed the evolution from clustered particulates at 30 min to betterdispersed nanoparticles after 6 h, with particle sizes between ca. 21 and 48 nm. XPS analysis of the nanofilm confirmed the presence of the W 6+ oxidation state and the success of silver decoration. Moreover, the Raman spectra revealed a monoclinic WO3 crystal structure and enhanced electronic properties due to the oxygen vacancies created by Ag decoration. The degree of degradation resistance was greater than that of the chitosan-WO3 films without silver decoration, as revealed by the thermal analysis data.