A Simple Approach to Generate Hollow Carbon Nanospheres Loaded with Uniformly Dispersed Metal Nanoparticles

We describe a simple and versatile method to synthesize hollow carbon nanospheres (HCNs) loaded with well-distributed metal nanoparticles (i.e., Ir-HCNs, MoO2-HCNs, and WO2/WO3-HCNs). This procedure uses the electrostatic interaction between negatively charged metal precursors and positively charged micelle templates made of poly(styrene-b-2-vinyl pyridine-b-ethylene oxide). The ion pairs are neutralized inside the micelles and then coated with a layer of phenolic resol. Pyrolysis transforms the nanoparticles into HCNs decorated with metal/metal oxide nanoparticles. HCNs are an excellent substrate for the in situ growth of metal nanoparticles, and this procedure can even provide reasonable control over the average size of the metal nanoparticles.