Pitaya pulp structural cobalt–carbon composite for efficient hydrogen generation from borohydride hydrolysis

Abstract

The design and synthesis of high efficiency catalysts for hydrogen generation and storage are the key factors for large-scale hydrogen use. Herein, a Pitaya pulp structural cobalt-based carbon nanocatalyst is synthesized. The 5–10 nm Co/CoOx particles are uniformly distributed in the 500-nm spherical carbon matrix and enable efficient catalytic performance during hydrogen generation from the alkaline NaBH4 and NH3BH3 solutions at 3998 mL min−1·gCo−1 for NaBH4 and 4677 mL min−1·gCo−1 for NH3BH3. The catalyst nanoparticles were prepared by a facile one-pot solution reaction, pyrolysis at high temperature, and oxidation in air. The coexistence of various valence states of Co in the composite material is observed by utilizing various characterization methods. Co nanoparticles fixed in the carbon matrix effectively prevent particles from aggregation and loss. This unique structure's similarity with Pitaya pulp, its synergistic effects, and its self-stirring mode enable its effective catalytic performance and good stability. The results provide a reference direction for the design and synthesis of unique structure catalysts for efficient hydrogen production.