Facile and green synthesis of cellulose nanocrystal-supported gold nanoparticles with superior catalytic activity

• The synthesis of CNC-supported AuNPs is green, facile and one-pot.
• Large amount of highly dispersed AuNPs are loaded on CNCs.
• Most of the AuNPs are smaller than 10 nm, and ca. 60% of them are smaller than 5 nm.
• CNC-supported AuNPs exhibited superior catalytic activity for the reduction of 4-NP.

The emphasis of science and technology shifts toward environmentally friendly and sustainable resources and processes. Herein, we report a facile, one-pot and green synthesis of biomaterial-supported gold nanoparticles (AuNPs) with superior catalytic activity. Cellulose nanocrystal (CNC)-supported AuNPs were prepared by heating the aqueous mixture of HAuCl4, CNCs and polyethylene glycol, avoiding toxic chemicals, extreme condition and complicated procedure. The resultant CNC-supported AuNPs exhibited catalytic activities for the reduction of 4-nitrophenol by sodium borohydride. The maximum apparent rate constant reached 1.47 × 10−2 s−1, and the turnover frequency reached 641 h−1. The superior catalytic performance can be ascribed to the large amount of highly dispersed AuNPs with few nanometers in size which are loaded on CNCs. About 90% of the AuNPs are smaller than 10 nm, and nearly 60% of the AuNPs are smaller than 5 nm. The synthesis is eco-friendly, facile and low-cost, thus has great potential for industrial and medical applications.