Multimetal Borides Nanochains as Efficient Electrocatalysts for Overall Water Splitting

Yingjie Li; Bolong Huang; Yingjun Sun; Mingchuan Luo; Yong Yang; Yingnan Qin; Lei Wang; Chunji Li; Fan Lv; Weiyu Zhang; Shaojun Guo

doi:10.1002/smll.201804212

Multimetal Borides Nanochains as Efficient Electrocatalysts for Overall Water Splitting

Small. 2019 Jan;15(1):e1804212. doi: 10.1002/smll.201804212. Epub 2018 Dec 5.

Authors

Yingjie Li¹, Bolong Huang², Yingjun Sun^{1

3}, Mingchuan Luo¹, Yong Yang¹, Yingnan Qin^{1

3}, Lei Wang³, Chunji Li¹, Fan Lv¹, Weiyu Zhang¹, Shaojun Guo^{1

4

5

6}

Affiliations

¹ Department of Materials Science and Engineering College of Engineering, Peking University, Beijing, 100081, China.
² Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, 999077, Hong Kong SAR, China.
³ College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
⁴ BIC-ESAT, College of Engineering, Peking University, Beijing, 100871, China.
⁵ Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing, 100871, China.
⁶ Beijing Key Laboratory for Magnetoeletric Materials and Devices, Peking University, Beijing, 100871, China.

PMID: 30515971
DOI: 10.1002/smll.201804212

Abstract

The development of cost-efficient, active, and stable electrode materials as bifunctional catalysts for electrochemical water splitting is crucial to high-performance renewable energy storage and conversion devices. In this work, the synthesis of Co-based multi-metal borides nanochains with amorphous structure is reported for boosting the oxygen evolution (OER) and hydrogen evolution reactions (HER) by one-pot NaBH₄ reduction of Co²⁺ , Ni²⁺ , and Fe²⁺ under ambient temperature. In all the investigated Co-based metal borides, NiCoFeB nanochains show the excellent OER performance with a low overpotential of 284 mV at 10 mA cm^-2 and Tafel slope of 46 mV dec^-1 , respectively, together with excellent catalytic stability, and robust HER performance with an overpotential of 345 mV at 10 mA cm^-2 . The density functional theory (DFT) calculations reveal that the excellent electrocatalytic performance is mainly attributed to optimal electronic structure by tuning the Co-3d band activities by the incorporation of Ni and Fe for enhanced water splitting via the potentially existed Co⁰ state. Moreover, the electrolyzer using NiCoFeB nanochains as anode and cathode offers 10 mA cm^-2 at a cell voltage of 1.81 V, comparable to commercial Pt/C // Ir/C, providing a simple method to design and explore highly efficient and cheap bifunctional electrocatalysts for overall water splitting.

Keywords: Co-based multimetal borides; nanochains; overall water splitting; regulable electronic structure.

Abstract

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