Synthesis of Dandelion-like Porous Au Nanoparticles for Catalytic Reduction of Nitrophenol

Abstract

Background: Porous Au nanomaterials show great potential in the fields of biomedicine, drug delivery, and catalysis for the merits of low density, large void space, and large specific surface area. The preparation of porous Au nanomaterials is usually carried out by using a hard-templating method, which is cumbersome. Methods: Dandelion-like porous Au nanoparticles were synthesized through a soft-templating method in our work. The synthesized porous Au nanoparticles were characterized via transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and cyclic voltammetry (CV). The reduction of nitrophenol was carried out to evaluate the catalytic behavior of porous Au nanoparticles. Results: Porous Au nanoparticles prepared were in uniform size (47.9±6.4 nm) and the morphology could be regulated by adjusting the molar ratio of reactants. The apparent rate constant (kapp) value of reducing nitrophenol catalyzed by porous Au nanoparticles was higher than Au nanospheres and nanobranches in a similar size. It could be attributed to a large amount of active sites and high proportion of high-order crystal faces proved by CV and XRD. Conclusion: We developed a facile and reproducible method for synthesizing porous Au nanoparticles. The morphology of porous Au nanoparticles can be ajusted by changing the molar ratio of reactants. Porous Au nanoparticles that we prepared behaved better in catalysis compared with Au nanospheres and Au nanobranches.