In situ formed nickel phosphide/iron oxide heterojunction for accelerating hydrogen generation

Abstract

Designing cost-effective catalysts with the structural features and necessary functionality to drive ammonia borane hydrolysis for hydrogen generation remains a challenge. In this work, a close heterojunction of Fe₃O₄–Ni₂P uniformly embedded in amorphous carbon material (Fe₃O₄–Ni₂P@C) has been prepared via surface phosphorization. The catalyst displays superior activity with a turnover frequency (TOF) of 92.8 min⁻¹ and favorable durability for ammonia borane hydrolysis, making it superior to most reported nickel-based catalysts. The theoretical studies show a high electron density on the Fe₃O₄–Ni₂P heterojunction. Combining the theoretical and experimental results, the dual active sites at the heterojunction are beneficial to the adsorption of reactant molecules and the reduction of the reaction barrier. This strategy of constructing an appropriate heterojunction to maximize synergistic effects may open a new avenue for non-precious metal catalysis.