Enhanced Catalytic Property Of Au Nanoparticles In O-Nitroaniline Reduction By Simple Addition Of Graphene Oxide

Noble metal nanomaterial have excellent catalytic properties due to size effect and high specific area. Because their catalytic performance is highly dependent on size and morphology, the controllable preparation of metal nanoparticles are of great importance. A novel method to prepare gold nanorods with high yield and uniform size by using1,2,4-trihydroxybenzene and 1,2,3-trihydroxybenzene as reducing agents was developed. Enhanced the catalytic activity of gold nanomaterials by simple addition of GO in reduction of o-nitroaniline. The main research contents are as follows:(1) Preparation of gold nanorods using 1,2,4-trihydroxybenzene, and1,2,3-trihydroxybenzene as reducing agents by seed-mediated method.The effect of changing various parameters including silver concentration,reducing agent, and seed was examined. The results show that monodisperse gold nanorods with longitudinal surface plasmon resonance tunable from 698 to 913 nm can be synthesized by1,2,4-trihydroxybenzene as a reducing agent, and the largest aspect ratio of the GNRs was 4.9; gold nanorods with longitudinal surface plasmon resonance tunable from 630 to 880 nm can be synthesized by1,2,3-trihydroxybenzene as a reducing agent, and the largest aspect ratio of the GNRs was 4.7. These results indicate that the GNRs prepared by1,2,3-trihydroxybenzene and 1,2,4-trihydroxybenzene have wider LSPR tunable range than the GNRs prepared by AA.(2) Preparation of GO using a modified Hummers method. GO was characterized by SEM 、 UV-Vis 、 FT-IR and Zeta potential. The results show that, the surface of GO is rich in oxygen-containing functional groups. Zeta potential result showed that GO is negatively charged in a neutral aqueous solution, and the Zeta potential was-36.4 m V.(3) Catalytic reduction of o-nitroaniline. GNRs, Au-citrate and Au-CTAC were chose as catalyst in reduction of o-nitroaniline by sodium borohydride. the catalytic activity of these catalysts can be improved by simple addition of GO, the reaction rate increased with increasing theconcentration of GO. Under the same condition, Au-citrate exhibited higher catalytic activity than Au-CTAC towards reduction of o-nitroaniline.