Dealloying Generation of Oxygen Vacancies in the Amorphous Nanoporous Ni–Mo–O for Superior Electrocatalytic Hydrogen Generation
Yin’an Zhu, Ye Pan, Weiji Dai, Tao Lü
Abstract
Electrochemical splitting of water to hydrogen is widely considered as an efficient and sustainable solution to relieve the energy crisis. In this work, we report a facile dealloying method based on metallic glass (Ni61Zr36Mo3) to introduce abundant oxygen vacancies (Ov) for the electrocatalytic hydrogen evolution reaction (HER). The corroded ribbons are composed of a sandwich-like structure with Ni–Mo–O nanoporous layer outside and raw metallic glass inside. This complex structure delivers a low overpotential of 71 ± 2.6 mV at −20 mA cm–2geo in 1.0 M KOH solution, a Tafel slope of 57 ± 3 mV dec–1, and 100 h long-term stability for HER, which is much better than those of the crystallized counterpart, nanoporous Ni, and the commercial benchmark 20% Pt/C electrocatalyst. The high concentration of oxygen vacancies (71.5%), the alloying effect of Mo, and amorphous composition synergistically contribute to the superior electrocatalytic ability and enhanced reaction kinetic of nanoporous Ni–Mo–O, indicating it an excellent low-cost alternative for platinum in hydrogen production.