Fig. 11. UV-visible spectra for the reduction of 2-nitroaniline (a) with NaBH₄ in the absence of catalyst. (b) In the presence of catalyst without NaBH₄. (c) With NaBH₄ in the presence of catalyst. (d) Plot of ln(A_t/A_o) vs. time. Reaction conditions: 1 mM 2-NA = 40 mL, 0.1 M NaBH₄ = 1.5 g, catalyst = 100 μL.