Fabrication of Pt-Ag-Au heterogenous truncated hollow sub-microspheres for chemically self-propelled colloidal motors

Abstract

The colloidal motors with cavity structure, which have advantages over solid motors in catalytic efficiency, cargo capacity and biocompatibility, are still expected. Here, we design and fabricate a type of truncated hollow sub-microspheres via organic colloidal template-etching/heating and layer by layer- isotropic deposition. The as-prepared truncated hollow sphere is of one circular open-pore through the shell-layer and built of Pt, Ag and Au shell-layers from inside to outside. They are controllable in sphere diameter, circular open-pore’s size and shell thickness, which depend on the template and deposition conditions. Further experiments have shown that the Ag sandwich layer and post-deposition ageing process are crucial to obtain the strong and complete truncated hollow sub-microspheres. Their formation is attributed to the template geometry and nearly isotropic deposition. Due to the catalytic Pt layer on the inner surface and the truncated hollow spherical structure, such Pt-Ag-Au hollow spheres are demonstrated to be the chemically-propelled colloidal motor, which can directionally move in the H2O2–contained solutions. This study presents a controllable route for mass-fabricating heterogenous multi-layer truncated hollow sub-microspheres, and provides a new type of chemically self-propelled colloidal motors.

Pt-TiO2 Bilayered Hemispherical Nanoshells with Tunable Pt Distribution for Chemically Self-Propelled Colloidal Motors

“…These micromotors showed different motion behaviors, which is the joint influence of the shape and Pt distribution on motors’ motion, and it is difficult to distinguish their separate influences. Alternatively, for colloidal motors with uncommon shapes, such as bowl-shaped motors, − it is seemingly easier to modulate their active components’ distribution due to their lower geometric symmetry. However, to our best knowledge, a wide modulation of active components’ distribution for colloidal motors with a specific shape is rarely reported, although it is crucial to understanding and controlling the motors’ motion behaviors.…”