Engineering Precursor Localization via Solvency for Simultaneously Metallizing and Hollowing Bicontinuous Gyroid Structures.

Abstract

Metallized ordered porous nanonetworks offer exceptional performance due to their robust bicontinuous interconnected frameworks with a large surface area. However, further enhanced porosity remains a challenge. The most efficient approach is to simultaneously hollow and metallize these nanonetworks, dominated by precisely controlling the associated distribution of the guest metallic precursor. Here, the challenges in maintaining the structural integrity of the double gyroid (DG) structure while enhancing porosity are overcome by direct metallizing and hollowing the DG hybrid into tungsten oxide (WO₃) hollow double gyroid (HG) architectures using polystyrene-block-poly(4-vinyl pyridine) (PS-b-P4VP) block copolymers. Unlike typical hybridization where guest precursors distribute uniformly, the approach leverages the ionization of bicontinuous P4VP frameworks and the solvency of metallic precursors to precisely control precursor association. This results in two distinct hybridizations: homogeneous dispersion within the P4VP framework or heterogeneous localization at microphase-separated interfaces. The heterogeneous localization can lead to the formation of the unique core-shell triclinic DG hybrid, distinct from the conventional cubic DG. Through sequential calcination, the core-shell DG hybrid can be simultaneously metallized and hollowed into crystalline WO₃-based HG structures with exceptional porosity. This engineering precursor distribution is also valid for amphiphilic copolymer-derived ordered and disordered nanonetworks, paving advanced applications in nanopatterning, metamaterials, and catalysis.