Hierarchical nanoporous microtubes for high-speed catalytic microengines

Powerful micro-/nano-motors with high speeds and large driving forces in fluids are of great importance in propelling micro-/nanomachines for various tasks. Here, we achieved highly efficient catalytic locomotion in microtubular engines with hierarchical nanoporous walls. The sophisticated structures provide an enlarged surface area and improved reactant accessibility, which remarkably enhanced their catalytic activity toward H2O2 decomposition, accelerating the microengine's speed. The fast catalytic locomotion of such hierarchical nanoporous microtubes makes them excellent candidates as efficient micro-machines for biomedical applications.