Thin layer chitosan-coated cellulose filter paper as substrate for immobilization of catalytic cobalt nanoparticles

A facile approach utilizing synthesis of cobalt nanoparticles in green polymers of chitosan (CS) coating layer on high surface area cellulose microfibers of filter paper (CFP) is described for the catalytic reduction of nitrophenol and an organic dye using NaBH₄. Simple steps of CFP coating with 1wt% CS aqueous solution followed by Co²⁺ ions adsorption from 0.2M CoCl₂ aqueous solution were carried out to prepare pre-catalytic strips. The Co²⁺ loaded pre-catalytic strips of CS-CFP were treated with 0.19M NaBH₄ aqueous solution to convert the ions into nanoparticles. Successful Co nanoparticles formation was assessed by various characterization techniques of FESEM, EDX and XRD analyzes. TGA analyses were carried out on CFP, CS-CFP, and Co-CS-CFP for the determination of the amount of Co particles formed on the CS-FP, and to track their thermal properties. Furthermore, we demonstrated that the Co-CS-CFP showed an excellent catalytic activity and reusability in the reduction reactions a nitroaromatic compound of 2,6-dintirophenol (2,6-DNP) and brilliant cresyl blue (BCB) dye by NaBH₄. The Co-CS-CFP catalyzed the reduction reactions of 2,6-DNP and BCB by NaBH₄ with psuedo-first order rate constants of 0.0451 and 0.1987min^-1, respectively.