Fig. 9
a, b The relationship between ln(C t /C 0) and time (sec) of 4-NP reduction reaction with either AC-AuNP or cf-AC-AuNP catalysts in the presence of excess sodium borohydride. AC-AuNPs were synthesized with different extract concentrations. cf-AC-AuNPs were prepared by centrifugation of AC-AuNPs. The detailed procedure is in the experimental section. (circle) 0.015 %, (inverted triangle) 0.025 %, (square) 0.035 %, (diamond) 0.045 %, (triangle) 0.055 %