A porous aerogel nanocomposite of silver nanoparticles-functionalized cellulose nanofibrils for SERS detection and catalytic degradation of rhodamine B

Abstract

Herein, cellulose nanofibrils (CNFs) were functionalised with silver nanoparticles (AgNPs) via a green in situ hydrothermal synthesis approach. The presence of active functional groups on the CNFs favours the direct synthesis and growth of AgNPs on the nanofibrils without the use of an external reducing agent. The freeze-dried CNF–AgNPs aerogel nanocomposite exhibited a highly porous structure, as revealed by FESEM. An organic dye, rhodamine B (RhB), was chosen to investigate the characteristics of the produced nanocomposite. Detection of the dye via Raman spectroscopy and analysis of catalytic capabilities by degradation of the dye were used to define the nanocomposite's properties. The nanocomposite showed significant enhancement in detection of signal for RhB in aqueous solution, as compared to the neat CNF, which is attributed to the surface-enhanced Raman scattering effect (SERS) of the immobilized AgNPs. Moreover, the CNF–AgNPs nanocomposite also showed sensitivity for detecting RhB at different concentrations, ranging from 5 × 10⁻³ M to 5 × 10⁻⁷ M. In addition, the nanocomposite exhibited a notable catalytic effect on the degradation of RhB in the presence of sodium borohydride.