Amorphous Ni(OH)2 encounter with crystalline CuS in hollow spheres: A mesoporous nano-shelled heterostructure for hydrogen evolution electrocatalysis

Highly active, durable and cost-effective eletrocatalysts are crucial for hydrogen evolution reaction (HER). Herein, we report novel hollow hybrid spheres comprising of amorphous Ni(OH)2 and crystalline CuS mesoporous nano-shelled heterostructures as efficient HER electrocatalysts. Spherical Cu2O particles are used as templates for fabrication of Ni(OH)2@CuS hollow spheres with nano-shelled heterostructures. The as-obtained catalysts exhibit much higher performance than the single Ni(OH)2, CuS, their physical mixture and crystalline Ni(OH)2@CuS toward water electrochemical reduction in alkaline medium. The superior HER electrocatalytic performance might be attributed to the unique hollow mesoporous nanoshelled architecture and the heterostructured synergetic effects between amorphous Ni(OH)2 and crystalline CuS, in which the short-range order of the inner amorphous Ni(OH)2 mesoporous shell creates abundant active sites on the surface, and the conductive CuS out layer promotes electron transportation. This work might open a door for designing and synthesizing of hollow nanomaterials with mesoporous nano-shelled heterostructures consist of amorphous and crystalline phase for applications in electrochemical catalysis and energy conversion.