Bioinspired Unidirectional Silk Fibroin‐Silver Compound Nanowire Composite Scaffold via Interface‐Mediated In Situ Synthesis

: Bioinspired unidirectional porous materials have emerged as a unique class of scaffolds for the fabrication of macroscopic nanomaterial assemblies. However, these scaffolds usually serve simply as mechanical carriers to support various building blocks. Here, we report that the unidirectional silk fibroin scaffold can not only act as a carrier, but also serve as a controllable multiscale reactor to achieve the in situ synthesis of a Ag3 PO4 nanowire network anchored to ordered channels. Both the silk fibroin matrix and the interface play important roles in the nucleation and growth of the Ag3 PO4 nanowires. This unidirectional composite scaffold can be used for efficient water disinfection. Furthermore, the facile chemical transformation of Ag3 PO4 in the composite scaffold into Ag2 S provided an analogous unidirectional composite silk scaffold that displays both efficient solar water evaporation effect and antibacterial activity. It is expected that this method can be extended to fabricate a series of silk-based unidirectional composite scaffolds with varying functionalities.