Cellulose nanocrystal/hexadecyltrimethylammonium bromide/silver nanoparticle composite as a catalyst for reduction of 4-nitrophenol.

The application of metal nanoparticles (NPs) in catalysis has drawn significant research interest, including in their applications to the wastewater treatment. Nanocellulose can be a versatile support/carrier in stabilizing metal NPs catalysts, due to its unique properties. In this paper, hexadecyl-trimethylammonium bromide (CTAB) surfactant-adsorbed cellulose nanocrystals (CNC) was employed as a support for silver nanoparticles (Ag NPs). The obtained CNC/CTAB/Ag nanohybrid composite was characterized by ultraviolet-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The results of the catalytic reaction experiments showed that Ag NPs immobilized on CTAB-adsorbed CNC displayed higher catalytic efficiency towards the reduction of 4-nitrophenol to 4-aminophenol, compared to the control Ag NPs and CNC/Ag samples. The enhanced catalytic performance of Ag NPs was attributed to the improved dispersity and narrow distribution of silver nanoparticles in the catalytic system. This work provides a novel catalyst based on CNC-CTAB stabilized Ag NPs which would have promising applications towards catalytic treatment of wastewater.