Temporally Programmed Access to Variously Structured Nanoelectrocatalysts by Unlocking “High Energy” Polymeric Composite Micelles

Structures impact the performance of nanocatalysts, but optimizing them by altering their structures is tedious and restricted. We present a strategy using “high energy” polymeric composite micelles as precursors to produce variously structured nanocatalysts in a simple, temporally controlled manner. By incubating core–shell spherical micelles of poly(ethylene glycol)-b-poly(4-vinylpyridine) with a molybdate hydrate complexable with poly(4-vinylpyridine), the molybdates cross-link and enlarge the confined poly(4-vinylpyridine) core, producing “high-energy” and “crosslinking-locked” polymeric composite micelles. Properly increasing the temperature weakens the cross-linking and releases the energy at a suitable rate, facilitating the stepwise transition of the polymeric composite micelles into various structures. Cooling the system at specific phases generates worm-like, flower-like, and clustered structures that further develop into molybdenum phosphide (MoP) nanoworms, nanoflowers, and nanoclusters, respectively. MoP nanoworms demonstrate the highest efficiency as nanoelectrocatalysts for hydrogen evolution, surpassing previously reported MoP-based catalysts and even commercial Pt/C catalysts in high current density regions.