材料科学
析氧
纳米颗粒
纳米材料基催化剂
电化学
化学工程
电催化剂
异质结
密度泛函理论
贵金属
石墨烯
催化作用
碳纤维
镍
纳米技术
金属
物理化学
复合数
化学
电极
冶金
复合材料
计算化学
工程类
生物化学
光电子学
作者
Sujin Seok,Minseon Choi,Yeunhee Lee,Dawoon Jang,Yunseok Shin,Yong Hyun Kim,Changbum Jo,Sunghee Park
出处
期刊:ACS applied nano materials
[American Chemical Society]
日期:2021-09-09
卷期号:4 (9): 9418-9429
被引量:23
标识
DOI:10.1021/acsanm.1c01908
摘要
Supported Ni-based nanocatalysts have attracted much attention to replace noble metal catalysts (e.g., IrO2) for the oxygen evolution reaction (OER) due to their low costs. However, their low activity is the main hindrance for their use in the practical OER application. In this study, a Ni-based core–shell material (Ni@Ni-NC) is produced through the heat treatment of a mixture of urea and NiCl2·(H2O)6. Multiple analysis data reveal that the Ni@Ni-NC consists of a Ni nanoparticle core and several tens of nanometer-thick, N-doped carbon (NC) shell materials, in which atomically attached Ni-based species were homogeneously distributed. Ni@Ni-NC exhibits excellent electrocatalytic OER performance with over- and onset potentials of 371 mV and 1.51 V, respectively, which are better than those of commercial IrO2. As control samples, structural and electrochemical properties of various composites (Ni nanoparticles + N-doped graphene, Ni nanoparticles + C3N4, atomically dispersed Ni on a C3N4 surface) and acid-treated Ni@Ni-NC are investigated. These experiments reveal that the well-dispersed Ni–NC species and core–shell structures play pivotal roles in improving the electrocatalytic OER performance. Furthermore, density functional theory (DFT) calculations suggest the dual-site OER mechanism of the Ni–NC active species with a significantly low reaction barrier. The mechanisms for the formation of core–shell structures are studied with control samples, which are produced from different heating times, and DFT calculation suggested that the core/shell structure formation is attributed to the cohesive energy of the Ni particles and strong bonds between the Ni and NC supports. This work provides a facile strategy for designing supported Ni catalysts with core–shell architecture for electrocatalytic reactions and other advanced applications.
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