Flower-like CoP coated NiMoO4 nanorods as self-supported core-shell heterojunction electrode can facilitate oxygen evolution reaction at a low overpotential

Abstract

Transition metal phosphates, as the most promising catalyst for oxygen evolution reaction (OER), have attracted much attention in recent years. In this work, CoP nanosheets are electrodeposited on NiMoO4 nanorods to form a self-supported core-shell structure electrode with CoP-NiMoO4 heterojunctions. Density functional theory (DFT) calculations demonstrate CoP-12@NiMoO4/NF electrode can reduce reaction energy barrier of rate-determining step (RDS) from 8.743 eV to 2.519 eV. In 1 M KOH, the electrode shows a low overpotential of 165 mV (10 mA cm−2), a low Tafel slope of 45 mV dec−1 and the significant stability. Compared with other non-noble metal OER electrocatalysts, the prepared CoP-12@NiMoO4/NF electrode exhibits better electrocatalytic activity, which can provide a new choice of electrocatalysts for future practical applications.

Keywords

• NiMoO4 nanorods arrays
• CoP nanosheets
• Self-supported core-shell structure
• Heterojunction
• Oxygen evolution reaction
• DFT