Identifying Dense NiSe2/CoSe2 Heterointerfaces Coupled with Surface High‐Valence Bimetallic Sites for Synergistically Enhanced Oxygen Electrocatalysis. Issue 26 (27th May 2020)

• Record Type: Journal Article
• Authors: Zheng, Xuerong; Han, Xiaopeng; Cao, Yanhui; Zhang, Yan; Nordlund, Dennis; Wang, Jihui; Chou, Shulei; Liu, Hui; Li, Lanlan; Zhong, Cheng; Deng, Yida; Hu, Wenbin
• Is Part Of: Advanced materials. Volume 32:Issue 26(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-05-27
• Subjects: active sites -- electrocatalysis -- heterostructures -- interface engineering -- metal–air batteries; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202000607
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Constructing heterostructures with abundant interfaces is essential for integrating the multiple functionalities in single entities. Herein, the synthesis of NiSe2 /CoSe2 heterostructures with different interfacial densities via an innovative strategy of successive ion injection is reported. The resulting hybrid electrocatalyst with dense heterointerfaces exhibits superior electrocatalytic properties in an alkaline electrolyte, superior to other benchmarks and precious metal catalysts. Advanced synchrotron techniques, post structural characterizations, and density functional theory (DFT) simulations reveal that the introduction of atomic‐level interfaces can lower the oxidation overpotential of bimetallic Ni and Co active sites (whereas Ni 2+ can be more easily activated than Co 2+ ) and induce the electronic interaction between the core selenides and surface in situ generated oxides/hydroxides, which play a critical role in synergistically reducing energetic barriers and accelerating reaction kinetics for catalyzing the oxygen evolution. Hence, the heterointerface structure facilitates the catalytic performance enhancement via increasing the intrinsic reactivity of metallic atoms and enhancing the synergistic effect between the inner selenides and surface oxidation species. This work not only complements the understanding on the origins of the activity of electrocatalysts based on metal selenides, but also sheds light on further surface and interfacial engineering of advanced hybrid materials. Abstract : Heterostructured NiSe2 /CoSe2 nanohybrids with different interfacial densities are synthesized via an innovative strategy of successive ion injection. Advanced synchrotron techniques and theoretical calculations demonstrate that the dense nanointerface structure can enhance the performance for oxygen electrocatalysis via increasing the intrinsic reactivity of metallic atoms and introducing a synergistic effect with surface electrochemically in‐situ‐formed oxides/hydroxides.