Construction of honeycomb-like Te-doped NiCo-LDHs for aqueous supercapacitors and as oxygen evolution reaction electrocatalysts

Abstract

The design and fabrication of hierarchical porous transition metal (oxy)hydroxide electrodes with desired electrochemical activities are highly demanded in electrocatalysis and supercapacitors. Herein, assisted by the dynamic oxygen bubble template method (DOBT), the tuned fabrication of honeycomb-like Te-doped nickel-cobalt layered double hydroxides (HS-Te-NiCo-LDHs) by controlled anodic electrodeposition was reported. It was found that the Te dopant helped to stabilize the more electroactive α-phase of NiCo-LDHs and the DOBT was efficient in constructing the hierarchical porous structure of the monolithic electrode. In addition, density functional theory (DFT) was applied to reveal the internal factors of the enhanced oxygen evolution reaction (OER) and supercapacitor performance of HS-Te-NiCo-LDH. The well-designed HS-Te-NiCo-LDH/NiO/NF electrode gave an ultralow overpotential of 221 mV at 10 mA cm⁻² as OER electrocatalyst with prolonged stability of over 24 hours (kept at ∼90 mA cm⁻²) and a high specific capacity of 650 C g⁻¹ for aqueous supercapacitor in 1 mol L⁻¹ KOH solution.