Facile Synthesis of Carbon Cloth Supported Cobalt Carbonate Hydroxide Hydrate Nanoarrays for Highly Efficient Oxygen Evolution Reaction.

Yubing Yan

doi:10.3389/fchem.2021.754357

Abstract

Developing efficient and low-cost replacements for noble metals as electrocatalysts for the oxygen evolution reaction (OER) remain a great challenge. Herein, we report a needle-like cobalt carbonate hydroxide hydrate (Co(CO3)0.5OH·0.11H2O) nanoarrays, which in situ grown on the surface of carbon cloth through a facile one-step hydrothermal method. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterizations demonstrate that the Co(CO3)0.5OH nanoarrays with high porosity is composed of numerous one-dimensional (1D) nanoneedles. Owing to unique needle-like array structure and abundant exposed active sites, the Co(CO3)0.5OH@CC only requires 317 mV of overpotential to reach a current density of 10 mA cm−2, which is much lower than those of Co(OH)2@CC (378 mV), CoCO3@CC (465 mV) and RuO2@CC (380 mV). For the stability, there is no significant attenuation of current density after continuous operation 27 h. This work paves a facile way to the design and construction of electrocatalysts for the OER.

Highlights

As a key anodic reaction, oxygen evolution reaction (OER) plays an important role in energy-relative electrochemical conversion technologies, such as water splitting and rechargeable Zn–air batteries (Song et al, 2020; Wu et al, 2020)
The needle-like Co(CO3)0.5OH nanoarrays were in situ grown on the surface of carbon cloth through a facile one-step hydrothermal method, where the Co(NO3)2 aqueous solution were used as precursors and urea as an alkaline reagent in the presence of NH4F at 120°C
NH4F is a good complexing ligand for Co2+ that can serve to reduce the concentration of free Co2+ ions, lowing the supersaturation to probably favor the gradual growth of needle-like Co(CO3)0.5OH nanoarrays (Zhu et al, 2013)

Summary

INTRODUCTION

As a key anodic reaction, oxygen evolution reaction (OER) plays an important role in energy-relative electrochemical conversion technologies, such as water splitting and rechargeable Zn–air batteries (Song et al, 2020; Wu et al, 2020). The low conductivity and deficient catalytically active sites of Co(CO3)0.5OH·0.11H2O limit its intrinsic OER activity in energy-relative electrochemical devices To address such problems, the introducing carbon support and morphology modulation should be two important strategies for improving the OER activity of transition metal-based materials. We report the anchoring of needle-like Co(CO3)0.5OH·0.11H2O nanoarrays on carbon cloth [Co(CO3)0.5OH@CC] with the assistance of urea and NH4F through a facile one-step hydrothermal method. Benefitted from needle-like array structure and abundant exposed active sites, the developed Co(CO3)0.5OH@CC displays superior electrocatalytic performance towards OER with a low overpotential of 317 mV at 10 mA cm−2 and a long-term stability. The electrochemical impedance spectroscopy (EIS) was collected in a frequency range from 0.01 Hz to 100 kHz at 1.7 V

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT