Electrospinning-thermal treatment synthesis: a general strategy to decorate highly porous nanotubes on both internal and external side-walls with metal oxide/noble metal nanoparticles.

The hybrid structure of nanoparticle-decorated highly porous nanotubes combines the advantages of large specific surface areas of nanoparticles and anisotropic properties of highly porous nanotubes, which is desirable for many applications, including batteries, photoelectrochemical water splitting, and catalysis. Here, we report a novel emulsion electrospinning–thermal treatment method to synthesize the nanoparticles deposited on both side walls of nanotubes with two unique characteristics: (1) large loading amount of nanoparticles per highly porous nanotubes (with the morphology of nanoparticles); (2) intimate contact between nanoparticles and highly porous nanotubes. Both features are advantageous for the above applications that involve both surface reactions and charge transportation processes. Moreover, the emulsion electrospinning–thermal treatment method is simple and straightforward, with which we have successfully decorated various highly porous metal oxide nanotubes with metal oxide or noble metal nanoparticles. The new method will have an impact on diverse technologies such as lithium ion batteries, catalysts, and photoelectrochemical devices.