%0 Journal Article
%A Wei, Xian-Kui
%A Xiong, Dehua
%A Liu, Lifeng
%A Dunin-Borkowski, Rafal E.
%T Self-Epitaxial Hetero-Nanolayers and Surface Atom Reconstruction in Electrocatalytic Nickel Phosphides
%J ACS applied materials & interfaces
%V 12
%N 19
%@ 1944-8252
%C Washington, DC
%I Soc.
%M FZJ-2020-02731
%P 21616 - 21622
%D 2020
%X Surface atomic, compositional, and electronic structures play decisive roles in governing the performance of catalysts during electrochemical reactions. Nevertheless, for efficient and cheap transition-metal phosphides used for water splitting, such atomic-scale structural information is largely missing. Despite much effort being made so far, there is still a long way to go for establishing a precise structure–activity relationship. Here, in combination with electron-beam bombardment and compositional analysis, our atomic-scale transmission electron microscopy study on Ni5P4 nanosheets, with a preferential (001) orientation, directly reveals the coverage of a self-epitaxial Ni2P nanolayer on the phosphide surface. Apart from the presence of nickel vacancies in the Ni5P4 phase, our quantum-mechanical image simulations also suggest the existence of an additional NiPx (0 < x < 0.5) nanolayer, characteristic of complex surface atom reconstruction, on the outermost surface of the phosphides. The surface chemical gradient and the core–shell scenario, probably responsible for the passivated catalytic activity, provide a novel insight to understand the catalytic performance of transition-metal catalysts used for electrochemical energy conversion.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:32301601
%U <Go to ISI:>//WOS:000535246100045
%R 10.1021/acsami.0c03154
%U https://juser.fz-juelich.de/record/878262