Unveiling the Hidden Value of Cotton Gin Waste: Natural Synthesis and Hosting of Silver Nanoparticles

[Image: see text] Cotton gin waste presents a significant challenge in the cotton ginning industry due to its abundant generation and limited disposal options. In this study, we explored the potential of cotton gin waste as a naturally occurring source material that can synthesize and host silver nanoparticles. The noncellulosic constituents of cotton gin waste served as effective reducing agents, facilitating the conversion of silver ions into silver atoms, while its porous structure acted as a microreactor, enabling controlled particle growth. A simple heat treatment of cotton gin waste powder in an aqueous silver precursor solution actualized the in situ synthesis of silver nanoparticles, without the need for additional chemical agents. Remarkably, a high concentration of silver nanoparticles (14.7%) with an average diameter of approximately 27 nm was produced throughout the entire volume of cotton gin waste. Electron microscopic images of cross-sectioned cotton gin waste confirm the internal formation of nanoparticles. Rietveld refinement analysis of X-ray diffraction patterns showed that the majority of the nanoparticles possess a cubic silver crystal structure. By leveraging the well-known biocidal properties of silver nanoparticles, the resulting silver nanoparticle-filled cotton gin waste holds promise for novel antimicrobial and antifungal material applications.