Figure 1.

Left panel: UV–vis absorption spectra of (a) CuSO4EG solution, (b) pH 11solution, and (c) transitional colorless solution. Right panel: UV–vis absorption spectra of copper colloids A, B, and C, which are synthesized under different molecular ratios of PVP and CuSO4, viz., (a) 2:1, (b) 10:1, and (c) 20:1, respectively

Zhang et al. Nanoscale Research Letters 2009 4:705-708   doi:10.1007/s11671-009-9301-2