Recent Advances on Controlled Synthesis and Engineering of Hollow Alloyed Nanotubes for Electrocatalysis.

The past decade has witnessed great progress in the synthesis and electrocatalytic applications of 1D hollow alloy nanotubes with controllable compositions and fine structures. Hollow nanotubes have been explored as promising electrocatalysts in the fuel cell reactions due to their well-controlled surface structure, size, porosity, and compositions. In addition, owing to the self-supporting ability of 1D structure, hollow nanotubes are capable of avoiding catalyst aggregation and carbon corrosion during the catalytic process, which are two other issues for the widely investigated carbon-supported nanoparticle catalysts. It is currently a great challenge to achieve high activity and stability at a relatively low cost to realize commercialization of these catalysts. An overview of the structural and compositional properties of 1D hollow alloy nanotubes, which provide a large number of accessible active sites, void spaces for electrolytes/reactants impregnation, and structural stability for suppressing aggregation, is presented. The latest advances on several strategies such as hard template and self-templating methods for controllable synthesis of hollow alloyed nanotubes with controllable structures and compositions are then summarized. Benefiting from the advantages of the unique properties and facile synthesis approaches, the capability of 1D hollow nanotubes is then highlighted by discussing examples of their applications in fuel-cell-related electrocatalysis. Finally, the remaining challenges and potential solutions in the field are summarized to provide some useful clues for the future development of 1D hollow alloy nanotube materials.