Steric hindrance colloidal microsphere approach to fabricate ordered and interconnected Pt or Pt/Ag hollow...

A steric hindrance colloidal microspheres approach (SHCMA) has been developed for the fabrication of ordered Pt or Pt/Ag nanoparticles composite interconnected hollow hemispheres via colloidal lithography and physical vapor deposition. Monolayer ordered silica or silica/Ag nanoparticles composite microspheres partly embedded into the polydimethylsiloxane (PDMS) were used as template, and Pt was sputtered on it. Due to the PDMS stamp functionalized as a steric hindrance substrate, which guaranteed that the ordered silica or silica/Ag nanoparticles composite microspheres were only coated with Pt film on the sides that exposed in air. After removing the template particles, large area ordered interconnected Pt or Pt/Ag nanoparticles composite hollow hemispheres were generated. The fabricated Pt hollow hemispheres have flat bottoms and are flexible and robust enough to be easily folded. In addition to successfully solving the challenge about ordered structure construction of the hollow Pt or Pt/Ag nanoparticles composite hemispheres here, we also could finely control the wall thickness of these hemispheres easily by changing the sputtering time or current.