Multifunctional human-hair nanocomposites for oxidation of alcohols, aza-Michael reactions and reduction of 2-nitrophenol

Novel nanocatalysts (Ni/HHP and Ru/HHP) were prepared by a very simple chemical reduction method. Fine human hair powder (HHp) was obtained from raw human hair (HH) by ball milling method. Readily leachable constituents were removed from HHp to obtain HHP. The HHP was employed as support for the decoration Ni and Ru nanoparticles (NPs). Strong interaction between ultrafine NPs and HHP was revealed. Weight percentage of Ru in Ru/HHP and Ni in Ni/HHP was determined to be 39.65% and 26.36%, respectively. Chemical state of nanocatalysts was studied by XPS and XRD analyses. Merit of Ru/HHP and Ni/HHP was realized from its excellent catalytic activity. The Ru/HHP and Ni/HHP worked well for the oxidation and aza-Michael reactions, respectively. Moreover, both Ni/ HHP and Ru/HHP were found to be excellent for the reduction of 2-nitrophenol (2-NP). Reusability, stability and heterogeneity of the catalysts were demonstrated. A mechanism has been proposed for catalytic systems.