Fig. 1. Schematic illustration of the preparation of the nanoframes composed of Co0.6Fe0.4P NPs coated with the carbon matrix. (i) Self-assembly of Co–Fe PBA; (ii) etching of the Co–Fe PBA to produce nanocages; (iii) phosphidation of the Co–Fe PBA nanocages to obtain subsequent Co0.6Fe0.4P NPs coated with the carbon matrix.
