RESUMO
The sluggish charge transfer and poor intrinsic activity are the obstacles that limit the development for electrocatalysts on hydrogen evolution. A novel core-shell heterostructure composed of Cu3P nanowires with supported CoO nanosheets was synthesized. Owing to numerous active sites and synergistic effect, the as-prepared Cu3P@CoO was highly efficient for hydrogen evolution and outperformed the single component. The theoretical calculations demonstrate that Cu3P@CoO had a zero bandgap for the incorporation of metallic Cu3P, which can greatly accelerate the charge transfer. Besides, the adsorption free energy of intermediates on Cu3P@CoO can also be optimized, leading to a small energy barrier in the reaction pathway, and thereby an increased intrinsic activity. This work highlights the significance of exploiting the synergistic effect of the heterostructure on the charge transfer and intrinsic activity when designing highly efficient electrocatalysts for hydrogen evolution.
RESUMO
The supported and dispersed ultrafine active species for electrocatalytic water oxidation are quite promising for the high intrinsic activity. A novel heterostructure of ultrafine FeOOH nanodots with an average size of 2.3â¯nm supported on CoAl-LDH nanosheets, is constructed by a facile method under ambient conditions. The as-prepared FeOOH@CoAl-LDH shows a strong interfacial interaction upon the formation of heterostructure, and is demonstrated as a highly efficient and stable electrocatalyst that demands 272â¯mV to attain 50â¯mAâ¯cm-2 and exhibits a Tafel slope of 40â¯mV dec-1. Moreover, density functional theory calculations manifest the coupling of FeOOH with CoAl-LDH can effectively decrease the energy barrier during the water oxidation process by optimizing the adsorption free energy of intermediates in the reaction pathway. The successful development of FeOOH@CoAl-LDH can shed light on the design of novel electrocatalysts that can fully take advantages of small size, heterostructure and synergistic effect.
