Ultrafast coloring-bleaching performance of nanoporous WO3-SiO2 gasochromic films doped with Pd catalyst.

The gasochromic performance and durability of WO(3)-based films can be improved by doping SiO(2) particles within WO(3) matrix forming nanoporous supporting network and dispersing Pd catalyst inside films with enhanced catalytic activity. Nanoporous WO(3)-SiO(2) composite films loaded with Pd catalyst were prepared by sol-gel dip-coating process and served as an active chromogenic layer to fabricate a double-glazed gasochromic device. The structure, morphology, optical properties and gasochromic performance of WO(3)-SiO(2) films were fully investigated. The WO(3)-SiO(2) films exhibit excellent gasochromic performance with ultrafast coloring rate of 14.8% per second (%/s) (WO(3): 2.84%/s) and bleaching rate of 44.1%/s (WO(3): 7.18%/s). The transmittance changed between 17.8 and 74.6% during coloring-bleaching cycles, and totally reversibility and stability were achieved.