Fig. 6. (a) XRD pattern of synthesized copper nanoparticles with the NaOH concentrations of 0 M (yellow curve), 0.25 M (blue curve) and ≥0.5 M (red curve); (b) color change and dispersibility of the solutions with the NaOH concentrations of 0 M; (c) color change and dispersibility of the solutions with the NaOH concentrations of 0.25 M and (d) color change and dispersibility of the solutions with the NaOH concentrations of ≥0.5 M.
