Rugae-like Ni2P-CoP nanoarrays as a bi-functional catalyst for hydrogen generation: NaBH4 hydrolysis and water reduction

Abstract

Designing a bifunctional catalyst that performs hydrolysis of metal hydrides and water reduction spontaneously is an essential step towards developing an integrated H2 storage system. Herein, a series of rugae-like CoP-Ni2P arrays decorated Ni foam (Ni-Cox-P@NF) are fabricated by two-step electrodeposition followed by phosphating treatment. The optimized Ni-Co20-P@NF catalyst shows a superior catalytic H2 generation by NaBH4 hydrolysis, giving a specific H2 generation rate of 4323.0 mL min−1 g−1 catalyst and good reusability, far better than most previously reported catalysts. Besides, the catalyst also exhibits an excellent electrocatalytic hydrogen evolution reaction with a low overpotential of 67.0 mV to reach −10 mA cm−2, small Tafel slope and long-term stability in 1.0 M KOH. The outstanding catalytic H2 generation capacity is attributed to the synergistically catalytic effect between the Ni2P and CoP species, as well as the unique composite structure with the benefit of solute transport and gas emission.