Green synthesis of nanowire-like Pt nanostructures and their catalytic properties

We reported a simple and effective green chemistry route for facile synthesis of nanowire-like Pt nanostructures at one step. In the reaction, dextran acted as a reductive agent as well as a protective agent for the synthesis of Pt nanostructures. Simple mixing of precursor aqueous solutions of dextran and K₂PtCl₄ at 80 °C could result in spontaneous formation of the Pt nanostructures. Optimization of the experiment condition could yield nanowire-like Pt nanostructures at 23:1 molar ratio of the dextran repeat unit to K₂PtCl₄. Transmission electron microscopy results revealed that as-prepared nanowire-like Pt nanostructures consisted of individual Pt nanoparticles with the size range from 1.7 to 2.5 nm. Dynamic light scattering analysis indicated that as-prepared nanowire-like nanostructures have already formed in solution. The as-prepared nanowire-like Pt nanostructures were further characterized by UV-vis spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. In addition, the ratio dependence and temperature dependence of this reaction have also been investigated. The as-prepared nanowire-like Pt nanostructures can be immobilized on glassy carbon electrodes using an electrochemical coupling strategy, and the resulting nanowire-like Pt nanostructures modified film exhibited an excellent electrocatalytic activity for the reduction of oxygen and the oxidation of NADH.