J. Mater. Sci. Technol. ›› 2023, Vol. 147: 207-216.DOI: 10.1016/j.jmst.2022.10.076

• Research Article • Previous Articles     Next Articles

Synergism and anion-cation dual chemical substitution in heterostructure sprouted on MXene enable high-efficiency and stable overall water splitting

Zepeng Lva, Jinshuai Feia, Yang Youa, Xuewei Lva, Qian Lib,c, Jie Danga,*   

  1. aCollege of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
    bNational Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China;
    cState Key Laboratory of Advanced Special Steels & Shanghai Key Laboratory of Advanced Ferrometallurgy, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
  • Received:2022-08-30 Revised:2022-10-23 Accepted:2022-10-25 Published:2023-06-01 Online:2022-12-28
  • Contact: * E-mail address: jiedang@cqu.edu.cn (J. Dang) .

Abstract: The exploration of novel, super-potent and low-cost electrocatalysts for water splitting has always been the kernel in the field of renewable sources. Herein, exfoliated Ti3C2Tx MXenes work as a substrate to vertically grow polypore N,Ni-Co2P nanoarrays (N,Ni-Co2P@TC) through an in situ interface-growth strategy and subsequent phosphorization and nitridation. The well-defined heterointerfaces with positive and negative ions co-modulation as coupled hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalysts for efficient overall water splitting are investigated, which possesses excellent durability even at a large current density (±500 mA cm-2). For HER, suitable H2O* and H* absorption energies and accelerated electronic transmission make N,Ni-Co2P@TC display a low overpotential of 27 mV at -10 mA cm-2 and Tafel slope of 38 mV dec-1 in 1 mol/L KOH. For OER, the synergy of N,Ni-Co2P@TC with self-reconfiguration can give enhanced activity with a low overpotential of 232 mV at 10 mA cm-2 and a Tafel slope of 57 mV dec-1. Additionally, the excellent bifunctional activity allows easily combining for efficient overall water splitting with a low driving voltage (1.51 V) at 10 mA cm-2, and the electrolyzer can be driven by a 1.5 V AAA battery.

Key words: Synergism, Chemical substitution, Heterostructure, Overall water splitting, MXene