Accurately Regulating the Electronic Structure of NixSey@NC Core–Shell Nanohybrids through Controllable Selenization of a Ni‐MOF for pH‐Universal Hydrogen Evolution Reaction. Issue 44 (13th October 2020)

• Record Type: Journal Article
• Authors: Huang, Zhaodi; Xu, Ben; Li, Zongge; Ren, Jianwei; Mei, Hao; Liu, Zhanning; Xie, Donggang; Zhang, Haobing; Dai, Fangna; Wang, Rongming; Sun, Daofeng
• Is Part Of: Small. Volume 16:Issue 44(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-13
• Subjects: controllable selenization -- electronic structure regulation -- NixSey@NC core‐shell nanohybrids -- pH‐universal electrocatalysts -- van der Waals interactions; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202004231
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: N‐doped carbon‐encapsulated transition metal selenides (TMSs) have garnered increasing attention as promising electrocatalysts for hydrogen evolution reaction (HER). Accurately regulating the electronic structure of these nanohybrids to reveal the underlying mechanism for enhanced HER performances is still challenging and thus requires deep excavation. Herein, a series of pomegranate‐like Ni x Se y @NC core–shell nanohybrids (including Ni0.85 Se @ NC, NiSe2 @NC, and NiSe@NC) through controllable selenization of a Ni‐MOF precursor is reported. The component of the nanohybrids can be fine‐tuned by tailoring the selenization temperature and feed ratio, through which the electronic structure can be synchronously regulated. Among these nanohybrids, the Ni0.85 Se @ NC exhibits the optimum pH‐universal HER performance with overpotentials of 131, 135, and 183 mV in 0.5 m H2 SO4, 1.0 m KOH, and 1.0 m PBS, respectively, at 10 mA cm −2, which are attributed to the increased partial density of state at the Fermi level and effective van der Waals interactions between Ni0.85 Se and NC matrix explained by density functional theory calculations. Abstract : Controllable selenization of a Ni‐MOF gives rise to pomegranate‐like Ni x Se y @NC core–shell nanohybrids with tunable stoichiometric ratio of Ni and Se and controlled pyrrolic N‐doping contents. Different Ni x Se y cores encapsulated in N‐doped carbon (NC) shells accurately regulate the electronic structure of Nix Sey @NC nanohybrids and the effective van der Waals interactions between Ni0.85 Se cores and NC shells enable Ni0.85 Se@NC nanohybrids pH‐universal hydrogen evolution reaction performances.