Fig. 1. UV-vis absorption spectra of 4-NP reduction in the presence of (a) 54 mg AuNS/pulp catalyst, (b) 27 mg AuNS/pulp catalyst, and (c) 13 mg AuNS/pulp catalyst. (d) Ct/C0vs. time plot. The insets in (b) and (c) show the spectra of the solution in the absence of the AuNS/pulp catalyst and AuNS (i.e. only in the presence of paper but not AuNS).
