CoMoO4-CoP/NC heterostructure anchored on hollow polyhedral N-doped carbon skeleton for efficient water splitting

Jiabing Luo; Yan Zhou; Xingzhao Wang; Yufeng Gu; Wanli Liu; Shutao Wang; Jun Zhang

doi:10.1016/j.jcis.2023.05.083

CoMoO₄-CoP/NC heterostructure anchored on hollow polyhedral N-doped carbon skeleton for efficient water splitting

J Colloid Interface Sci. 2023 Oct 15:648:90-101. doi: 10.1016/j.jcis.2023.05.083. Epub 2023 May 18.

Authors

Jiabing Luo¹, Yan Zhou¹, Xingzhao Wang², Yufeng Gu¹, Wanli Liu¹, Shutao Wang³, Jun Zhang⁴

Affiliations

¹ School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China.
² School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China; State Key Laboratory of Heavy Oil Processing, School of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
³ State Key Laboratory of Heavy Oil Processing, School of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
⁴ School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China; State Key Laboratory of Heavy Oil Processing, School of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China. Electronic address: yanzhou@upc.edu.cn.

PMID: 37295373
DOI: 10.1016/j.jcis.2023.05.083

Abstract

We report the synthesis and electrocatalytic properties of a CoMoO₄-CoP heterostructure anchored on a hollow polyhedral N-doped carbon skeleton (CoMoO₄-CoP/NC) for water-splitting applications. The preparation involved the anion exchange of MoO₄^2- to the organic ligand of ZIF-67, the self-hydrolysis of MoO₄^2-, and NaH₂PO₂ phosphating annealing. CoMoO₄ was found to enhance thermal stability and prevent active site agglomeration during annealing, while the hollow structure of CoMoO₄-CoP/NC provided a large specific surface area and high porosity that facilitated mass transport and charge transfer. The interfacial electron transfer from Co to Mo and P sites promoted the generation of electron-deficient Co sites and electron-enriched P sites, which accelerated water dissociation. CoMoO₄-CoP/NC exhibited excellent electrocatalytic activity for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1.0 M KOH solution, with overpotentials of 122 mV and 280 mV at 10 mA cm^-2, respectively. The CoMoO₄-CoP/NC‖CoMoO₄-CoP/NC two-electrode system only required an overall water splitting (OWS) cell voltage of 1.62 V to achieve 10 mA cm^-2 in an alkaline electrolytic cell. In addition, the material showed comparable activity to 20% Pt/C‖RuO₂ in a pure water home-made membrane electrode device, demonstrating potential for practical applications in proton exchange membrane (PEM) electrolyzers. Our results suggest that CoMoO₄-CoP/NC is a promising electrocatalyst for efficient and cost-effective water splitting.

Keywords: Heterointerface; Interfacial electron transfer; Overall water splitting; Spinel; Transition metal phosphide.