Self-Sustained-Release Strategy Realizes Colloid Oriented Assembly to Fabricate Prussian Blue with Hierarchical Structure.

Abstract

The controlled self-assembly of nanomaterials has been a great challenge in nanosynthesis, especially for hierarchical architectures with high complexity. Particularly, the structural design of Prussian blue (PB) series materials with robustness and fast nucleation is even more difficult. Herein, a self-sustained-release strategy based on the slow release of metal ions from coordination ions is proposed to guide the assembly of PB crystals. The key to this strategy is the slow release by ligand, which can create ultra-low concentrations of metal ions so as to provide the possibility to realize the surface charge manipulation of PB primary colloids. By adding electrolyte or changing the polarity of the solution, the surface charge regulation of PB colloid is realized, and the PB hierarchical structures with branch fractal structure (PB-BS), octahedral fractal structure, and spherical fractal structure are effectively constructed. This work not only achieves the designability of the PB structure, but also synchronizes the functionalization during the PB assembly growth process by in situ encapsulation of the effective catalytic active component L-Ascorbic acid. As a result, the assembled PB-BS exhibits greatly enhanced catalytic activity and selectivity in styrene oxidation with the selectivity of oxidized styrene increasing from 35.6% (PB) to 80.5% (PB-BS).