Elaboration of Ni2P@C Composites with Hollow Porous Structure for Enhanced Overall Water Splitting. Issue 22 (7th July 2022)

• Record Type: Journal Article
• Authors: Wang, Fei; Ding, Mingjie; Zhao, Danyang; Di, Haoxiang; Li, Jiafeng; Wang, Zhongxiao; Zhang, Zhiwei; Zhang, Luyuan; Wang, Chengxiang; Yin, Longwei
• Is Part Of: Advanced materials interfaces. Volume 9:Issue 22(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-07
• Subjects: electrocatalytic water splitting -- hydrogen evolution -- metal organic frameworks -- nickel phosphide -- water splitting; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202200673
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: The electrocatalytic water splitting is greatly affected by overpotential, stability, and accessibility of active sites. Designing appropriate active components and tailoring their microstructure are crucial to improve electrocatalytic performance. Herein, using metal organic framework (MOF) as template, novel Ni2 P@C composites are prepared as bifunctional catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The best Ni2 P@C‐350 sample has a small onset overpotential (η) of 57 mV, and up to 148 and 285 mV to afford 10 and 250 mA cm –2 for HER. It only needs η = 326 mV at 10 mA cm −2 for OER, better than usual RuO2 electrode. Moreover, Ni2 P@C‐350||Ni2 P@C‐350 cell can work for overall water splitting more efficiently than common Pt/C|| RuO2 cell, running stably within 30 h without obvious degradation. The excellent performance is attributed to its porous structure with easily accessible active sites, short ions transfer path, and superior structural stability, which enable a significant improvement on molecule level, e.g., the turnover frequency (TOF) of Ni2 P@C‐350 at η = 250 mV is up to 0.84 s −1, while that of pristine Ni2 P is only 0.55 s −1 . These results highlight the effect of structure engineering, inspiring for electrode design of HER and OER. Abstract : Ni2 P@C‐350 electrocatalyst with hierarchically hollow structure prevents the aggregation of nanoparticles and facilitates charge transfer, enhancing the hydrogen evolution reaction and oxygen evolution reaction performance in overall water splitting reaction. It highlights the significance of structure engineering for catalytic electrode design.