Mass Transport Determined Silica Nanowires Growth on Spherical Photonic Crystals with Nanostructure‐Enabled Functionalities

Abstract A robust and facile method has been developed to obtain directional growth of silica nanowires (SiO₂NWs) by regulating mass transport of silicon monoxide (SiO) vapor. SiO₂NWs are grown by vapor–liquid–solid (VLS) process on a surface of gold‐covered spherical photonic crystals (SPCs) annealed at high temperature in an inert gas atmosphere in the vicinity of a SiO source. The SPCs are prepared from droplet confined colloidal self‐assembly. SiO₂NW morphology is governed by diffusion‐reaction process of SiO vapor, whereby directional growth of SiO₂NWs toward the low SiO concentration is obtained at locations with a high SiO concentration gradient, while random growth is observed at locations with a low SiO concentration gradient. Growth of NWs parallel to the supporting substrate surface is of great importance for various applications, and this is the first demonstration of surface‐parallel growth by controlling mass transport. This controllable NW morphology enables production of SPCs covered with a large number of NWs, showing multilevel micro‐nano feature and high specific surface area for potential applications in superwetting surfaces, oil/water separation, microreactors, and scaffolds. In addition, the controllable photonic stop band properties of this hybrid structure of SPCs enable the potential applications in photocatalysis, sensing, and light harvesting.