Preparation of CoO/RGO@Ni Foam Electrode and Its Electrocatalytic Reduction of CO₂

Authors

Qian Guo, College of Environment and Chemical Engineering, Jiangsu Ocean University, Lianyungang 222005, Jiangsu, China;
Jia-Long Fu, College of Environment and Chemical Engineering, Jiangsu Ocean University, Lianyungang 222005, Jiangsu, China;
Cheng-Yan Zhang, College of Environment and Chemical Engineering, Jiangsu Ocean University, Lianyungang 222005, Jiangsu, China;
Chao-Yue Cai, College of Environment and Chemical Engineering, Jiangsu Ocean University, Lianyungang 222005, Jiangsu, China;
Cheng Wang, College of Environment and Chemical Engineering, Jiangsu Ocean University, Lianyungang 222005, Jiangsu, China;
Li-Hua Zhou, College of Environment and Chemical Engineering, Jiangsu Ocean University, Lianyungang 222005, Jiangsu, China;
Rui-Bo Xu, College of Environment and Chemical Engineering, Jiangsu Ocean University, Lianyungang 222005, Jiangsu, China;
Ming-Yan Wang, College of Environment and Chemical Engineering, Jiangsu Ocean University, Lianyungang 222005, Jiangsu, China;Follow

Corresponding Author

Ming-Yan Wang(mingyanlyg@hotmail.com)

Abstract

The worldwide extensive release of carbon dioxide (CO₂) has caused serious environmental pollution and unprecedented climate change problems. Thus, for the sustainable development of human society, it is very necessary to convert CO₂ to renewable fuels through clean and economical processes. The electrochemical CO₂ reduction reaction (CO₂RR) is regarded as a promising approach for the recycling of carbon resource and the generation of sustainable fuels. However, the slow kinetics and formation of multiple products in CO₂RR hinder its large-scale application. Hence, great research efforts are made to develop electrocatalysts with high product selectivity at low overpotential. Recently, nanostructured transition metal oxide based electrocatalysts have displayed quite exciting performances for the CO₂RR, in terms of fast kinetics, selectivity and durability. Among the various metal oxides, cobalt oxides show high CO₂RR activity, and selective for the formation of formic acid. In this paper, a hybrid of CoO nanoflowers grown onto three-dimensional (3D) reduced graphene oxide (RGO)@Ni foam (CoO/RGO@NF) was synthesized by a facile hydrothermal method. The composite electrode of CoO/RGO@NF was characterized by XRD and SEM. It is found that the CoO nanoflowers grew uniformly on the 3D network of RGO@NF electrode. The CoO nanoflowers were formed by a large number of nanorods around a center. The length of the nanorods was about 10 ~ 15 μm, and the diameter was about 100 ~ 200 nm. The electrocatalytic performance of CoO/RGO@NF composite electrode for CO₂ reduction was studied by cyclic voltammetry and linear scanning voltammetry. The results showed that the current efficiency of CoO/RGO@NF electrode for electrocatalytic reduction of CO₂ was 70.9% and the Faraday efficiency for formic acid production was 65.2%. In addition, the yield of formic acid on the electrode was 59.8 μmol·h^-1·cm^-2 at -0.76 V(vs. SHE) after 4 h of electrolysis. Furthermore, the current density was stable at about 90%. These data indicated that the as-prepared CoO/RGO@NF composite electrode had achieved excellent catalytic activity, selectivity and stability for CO₂ electroreduction.

Graphical Abstract

Keywords

CO2 electrocatalysis, hydrothermal method, nickel foam, CoO nanoflowers

DOI Link

https://doi.org/10.13208/j.electrochem.200513

Publication Date

2021-08-28

Online Available Date

2020-06-28

Revised Date

2020-06-03

Received Date

2020-05-12

Recommended Citation

Qian Guo, Jia-Long Fu, Cheng-Yan Zhang, Chao-Yue Cai, Cheng Wang, Li-Hua Zhou, Rui-Bo Xu, Ming-Yan Wang. Preparation of CoO/RGO@Ni Foam Electrode and Its Electrocatalytic Reduction of CO₂[J]. Journal of Electrochemistry, 2021 , 27(4): 449-455.
DOI: The worldwide extensive release of carbon dioxide (CO₂) has caused serious environmental pollution and unprecedented climate change problems. Thus, for the sustainable development of human society, it is very necessary to convert CO₂ to renewable fuels through clean and economical processes. The electrochemical CO₂ reduction reaction (CO₂RR) is regarded as a promising approach for the recycling of carbon resource and the generation of sustainable fuels. However, the slow kinetics and formation of multiple products in CO₂RR hinder its large-scale application. Hence, great research efforts are made to develop electrocatalysts with high product selectivity at low overpotential. Recently, nanostructured transition metal oxide based electrocatalysts have displayed quite exciting performances for the CO₂RR, in terms of fast kinetics, selectivity and durability. Among the various metal oxides, cobalt oxides show high CO₂RR activity, and selective for the formation of formic acid. In this paper, a hybrid of CoO nanoflowers grown onto three-dimensional (3D) reduced graphene oxide (RGO)@Ni foam (CoO/RGO@NF) was synthesized by a facile hydrothermal method. The composite electrode of CoO/RGO@NF was characterized by XRD and SEM. It is found that the CoO nanoflowers grew uniformly on the 3D network of RGO@NF electrode. The CoO nanoflowers were formed by a large number of nanorods around a center. The length of the nanorods was about 10 ~ 15 μm, and the diameter was about 100 ~ 200 nm. The electrocatalytic performance of CoO/RGO@NF composite electrode for CO₂ reduction was studied by cyclic voltammetry and linear scanning voltammetry. The results showed that the current efficiency of CoO/RGO@NF electrode for electrocatalytic reduction of CO₂ was 70.9% and the Faraday efficiency for formic acid production was 65.2%. In addition, the yield of formic acid on the electrode was 59.8 μmol·h^-1·cm^-2 at -0.76 V(vs. SHE) after 4 h of electrolysis. Furthermore, the current density was stable at about 90%. These data indicated that the as-prepared CoO/RGO@NF composite electrode had achieved excellent catalytic activity, selectivity and stability for CO₂ electroreduction.