Microwave solvothermal decoration of the cellulose surface by nanostructured hybrid Ag/ZnO particles: a joint XPS, XRD and SEM study

The synthesis of hybrid silver/zinc oxide (Ag/ZnO) decoration on the cellulose surface is described. The structures were characterized with X-ray photoelectron spectroscopy (XPS) and corroborated with X-ray diffraction and scanning electron microscopy. Silver nitrate and zinc acetate dihydrate were used as soluble raw materials. Hexamethylenetetraamine was used as the precipitating and reducing agent. The surface of α-cellulose was always treated by hydrogen peroxide before synthesis with a relatively mild effect manifested in water contact angle measurement and XPS high-resolution spectra. The Ag/ZnO decoration system was identified as a true nanodispersed metal/semiconductor hybrid with a unique collective plasmonic structure observed on Ag 3d core lines for the first time. A series of experiments with a single precursor solution contributed to the characterization of the interaction of Ag⁺ and Zn²⁺ species with the surface and to the description of the reaction mechanism in the mixed precursor solution. In contrast to previous reports, a specific interaction between the cellulose substrate and Zn²⁺ was observed. No specific non-thermal effects of microwave heating were observed.