Fabrication of Co(Ni)-P surface bonding states on core-shell Co(OH)2@P-NiCo-LDH towards electrocatalytic hydrogen evolution reaction

Abstract The application of NiCo-LDHs in the hydrogen evolution reaction (HER) is rarely reported because it is usually served as an effective electrocatalyst for oxygen evolution reaction (OER) owing to the essential chemical and electric structure features. It still is a challenge to realize the effective HER over NiCo-LDHs unless modified with noble metals. In this work, the noble-metal-free core–shell Co(OH)2@P-NiCo-LDH hybrid with dodecahedral hierarchical structure is prepared by the sacrificial template method along with subsequent phosphating process, which is available for the electrocatalytic HER. The fabricated Co(Ni)δ+-Pδ- bonding states on the surface of outer shell NiCo-LDH not only provide the abundant active centers but also reduce interfacial charge transfer resistance to enhance the HER activity. Meanwhile, the unique core–shell dodecahedral structure effectively avoids the agglomeration and restacking of NiCo-LDH nanosheets to improve the electrochemical stability. This work exploits a novel noble-metal-free modification strategy to expand the application of NiCo-LDH in HER.