In situ synthesis of Ag/Ag2O-cellulose/chitosan nanocomposites via adjusting KOH concentration for improved photocatalytic and antibacterial applications

This work proposed a facile way to construct cellulose/chitosan-loaded Ag/Ag2O nanocomposite films (ACC) from alkali/urea solution by increasing the content of alkali KOH in the solvent. The saturated alkali and hy-droxyl groups of the cellulose and chitosan chains were accelerated to convert AgNO3 to Ag0. Ag2O served as nuclei to lower the energy barrier. The formation of Ag/Ag2O nanoparticles (NPs) endowed the cellulose bio-reduced Ag composites with multifunction and stronger photocatalytic activity. Ag/Ag2O NPs with the diam-eter of 139-360 nm were uniformly dispersed in the composite films, resulting in superior mechanical properties (64.6 MPa) and thermal stability. Almost 92 % of methyl orange was degraded under UV-irradiation within 40 min by ACC. After 3 runs of degradation, the photocatalytic abilities of ACC remained. Moreover, the films exhibited good antibacterial activities. The width of inhibition zones around ACC reached 9.2-12 mm and 8.6-10.4 mm for S. aureus and E. coli. The strategy provided a new avenue to construct multifunctional cellulose/ chitosan materials for various applications, such as wastewater treatment, and electrocatalysis.