Loading behavior of Pt nanoparticles on the surface of multiwalled carbon nanotubes having defects formed via microwave treatment.

We developed a simple and efficient method to load Pt nanoparticles (NPs) uniformly on defects generated in multiwalled CNTs (MWCNTs) without using reduction agents or organic reagents. Defects on the surfaces of MWCNTs were artificially generated by microwave treatment at various exposure times. Nucleation of Pt NPs occurs on the defect sites spontaneously due to an innate electropotential difference. Because of the correlation between defects and Pt NPs, we were able to control the size of Pt NPs by changing defect size, quantity and distribution, which was confirmed by Raman spectroscopy and TEM. After microwave treatment for 3 min, more uniform and smaller Pt NPs were observed. Also, the defects via microwave treatment make adhesion of Pt NPs stronger, which can be helpful to improve the reliability for applications. Finally, the methanol oxidation behavior of MWCNTs with Pt NPs was examined by cyclic voltammetry (CV).