Magnetic-Field-Assisted Synthesis of Cobalt Nanowire Aerogels: Implications for Energy Storage and Electrocatalytic Applications

Cobalt aerogels present solutions to challenges in energy, sensing, and catalysis, but their syntheses have limitations including aggregation, required templates, and slow reactant diffusion times. We demonstrate a magnetic-field-assisted synthesis as a simple, fast, and scalable strategy to produce cobalt nanowire (CoNW) aerogels with tunable nanostructure, material phase, magneto-responsiveness, and accessible surface area for electrocatalytic applications. Varying the magnetic field revealed that higher applied fields favor longer, higher aspect ratio CoNWs. Thermal annealing allowed conversion of the CoNWs to Co₃O₄. Finally, the applied field strength and annealing parameters influenced the aerogel surface areas, pore volumes, magnetizations, coercivities, and specific capacitances.