Coupling heterostructured CoP-NiCoP nanopin arrays with MXene (Ti3C2Tx) as an efficient bifunctional electrocatalyst for overall water splitting

Deying Xu; Zhaoming Kang; Hongbin Zhao; Yiming Ji; Wenli Yao; Daixin Ye; Jiujun Zhang

doi:10.1016/j.jcis.2023.02.052

Coupling heterostructured CoP-NiCoP nanopin arrays with MXene (Ti₃C₂T_x) as an efficient bifunctional electrocatalyst for overall water splitting

J Colloid Interface Sci. 2023 Jun:639:223-232. doi: 10.1016/j.jcis.2023.02.052. Epub 2023 Feb 14.

Authors

Deying Xu¹, Zhaoming Kang¹, Hongbin Zhao², Yiming Ji¹, Wenli Yao³, Daixin Ye⁴, Jiujun Zhang¹

Affiliations

¹ Department of Chemistry & Institute for Sustainable Energy, College of Sciences, Shanghai University, Shanghai 200444, China.
² Department of Chemistry & Institute for Sustainable Energy, College of Sciences, Shanghai University, Shanghai 200444, China. Electronic address: hongbinzhao@shu.edu.cn.
³ Jiangxi Key laboratory of Power Battery and Material, Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China.
⁴ Department of Chemistry & Institute for Sustainable Energy, College of Sciences, Shanghai University, Shanghai 200444, China. Electronic address: daixinye@shu.edu.cn.

PMID: 36805747
DOI: 10.1016/j.jcis.2023.02.052

Abstract

Developing a highly effective bifunctional electrocatalyst for alkaline-condition electrochemical water splitting is both essential and challenging. The work presented here successfully synthesizes and employs a heterostructured CoP-NiCoP ultra-long nanopin array in situ growing on MXene (Ti₃C₂T_x) as a stable bifunctional electrocatalyst for electrochemical water-splitting. The heterogeneous structure formed by CoP nanoparticles and NiCoP nanopins provides extra active sites for water-splitting. Also, Ti₃C₂T_x works as a support substrate during electrochemical operations, accelerating mass transfer, ion transport, and rapid gas product diffusion. Meanwhile, throughout the catalytic process, the dense nanopin arrays shield Ti₃C₂T_x from further oxidation. At a result, the CoP-NiCoP-Ti₃C₂T_x (denoted as CP-NCP-T) demonstrated excellent catalytic activity, with overpotentials of just 46 mV for hydrogen evolution at 10 mA cm^-2 and 281 mV for oxygen evolution at 50 mA cm^-2. Furthermore, in 1.0 M KOH solution, the outstanding bifunctional electrode (CP-NCP-T || CP-NCP-T) exhibits efficient electrochemical water splitting activity (1.54 V@10 mA cm^-2) and outperforms the comparable device Pt/C || IrO₂ (1.62 V@10 mA cm^-2).

Keywords: CoP-NiCoP-Ti(3)C(2)T(x) nanopin arrays; Electrochemical water splitting; Heterogeneous structure.