Polyacrylate-assisted synthesis of stable copper nanoparticles and copper(I) oxide nanocubes with high catalytic efficiency

The synthesis of Cu nanoparticles (NPs) via the reduction of Cu ions with sodium borohydride in the presence of sodium polyacrylate is presented. The final Cu nanocrystals having a 14 nm diameter were generated via the aggregation and coalescence of the primarily formed ultrasmall particles (approx. 3 nm). Addition of sodium sulfite to the dispersions provided the protection of the Cu NPs against oxidation. On the other hand, the controlled aeration of the Cu NPs resulted in their transformation to Cu(2)O nanocubes with an average size of 18 nm. Both Cu NPs and Cu(2)O nanocubes can effectively catalyze reduction of 4-nitrophenol by sodium borohydride in aqueous solution.