Cellulose nanocrystal-mediated synthesis of silver nanoparticles: role of sulfate groups in nucleation phenomena.

Developing sustainable chemical methods to synthesize silver nanoparticles has drawn significant research interest. Due to their unique and well-defined physical-chemical properties, cellulose nanocrystals (CNCs) have become one of the most promising renewable nanomaterials. Here we use CNC to mediate silver nanoparticle synthesis and elucidate the effect of CNC surface chemistry (as defined by sulfate groups) in nanoparticle formation and nucleation in the presence of borohydride reduction. Pristine CNCs produced by sulfuric acid hydrolysis and partially desulfated CNCs mediated the formation of silver nanoparticles of different sizes (and size distribution) following different rates of formation, as determined by transmission electron microscopy (TEM) and UV-vis spectroscopy. The results shed light on methods to stabilize silver nanoparticles, control their nucleation, and highlight the potential of CNCs in metal nanoparticle synthesis.