Evaluation of catalytic activity of cellulose films decorated with gold nanoparticles in the reduction of 4-nitrophenol

Cellulose, due to its low cost, abundance, and biodegradability, has been considered a good choice of support gold nanoparticles (AuNPs). AuNPs based nanomaterials are efficient catalysts for many reactions, including the 4-nitrophenol (4-NP) reduction, which is used in many preparations of chemical and pharmaceutical industries and has toxic effects in living organisms. The cellulose film containing gold nanoparticles was prepared by spin coating a viscous solution of dissolved microcrystalline cellulose in 1-butyl-3-methylimidazolium chloride, followed by regeneration of the cellulose matrix as a film with water addition. Then, the as-prepared film was immersed in an aqueous dispersion of AuNPs, resulting in a red film containing AuNPs with diameters around 10 nm homogeneously dispersed in the polymeric matrix. This film showed great catalytic activity for the reduction of 4-NP to 4-aminophenol using NaBH₄, and it was efficient during five cycles. The catalyst prepared in this study has the advantage of being easily isolated from the reaction medium, avoiding processes of centrifugation or filtration for isolation and reuse.