Gold nanostructures are used as catalysts in heterogeneous catalytic processes and have intrigued chemists and materials scientists. Isotropic spherical gold nanoparticles (AuNPs) are ideal for catalysis due to their simple preparation process, controllable surface-active site, tunable size, and composition-dependent catalytic activity. In this study, spherical AuNPs with different size, composition, and surface capping agents have been prepared, and their catalytic activity in reduction of 4-nitrophenol (4-NP) is evaluated. The catalytic activity of AuNPs decreases as their size increases. Meanwhile, the catalytic activity of AuNPs with tartrate as the reducing agent show no evident changes because of containing anisotropic AuNPs. Moreover, silver not only improves monodisperse and spherical AuNPs, but also increases the catalytic activity of small AuNPs. Since the molecular structures of tartrate and citrate are similar, there is no remarkable difference in the catalytic activity of AuNPs using tartrate and citrate as capping agents. These results demonstrate the influence of size, composition, and surface capping on the catalytic activity of AuNPs. Overall, this study facilitates the applicability of gold-based catalyst and AuNPs in plasmonics, nanophotonics, biomedical photonics, and photocatalysis.
Keywords: 4-Nitrophenol; Catalyst; Gold nanoparticles; Monodisperse; UV–vis spectrum.
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