RETRACTED ARTICLE: Preparation of hollow Au_x-Cu₂O nanospheres by galvanic replacement to enhance the selective electrocatalytic CO₂ reduction to ethanol

Abstract

Electrocatalytic CO₂ reduction to fuel is one of the important ways to solve energy and environmental problems. In this work, the preparation of hollow Au_x-Cu₂O electrocatalyst and the performance of electrocatalytic CO₂ reduction to ethanol were studied. Hollow Cu₂O nanospheres were prepared by a soft template method, and Au_x-Cu₂O composites were prepared by galvanic replacement. The characterization results of XRD and XPS reveal that Cu⁺ is the main chemical state of Cu in the catalysts. The results of electroactive surface area demonstrate that the electroactive surface area of Au_0.51-Cu₂O is the largest. The performance evaluation of electrocatalytic CO₂ reduction shows that the Faraday efficiency of H₂ on Au_0.51-Cu₂O is the lowest (∼19.5%) and the Faraday efficiency of ethanol can reach ∼18.8% at −1.2 V vs. RHE. Compared with hollow Cu₂O nanospheres, Au_x-Cu₂O catalysts have an earlier onset for ethanol production and promote the CO₂ reduction to ethanol with high efficiency, while the hydrogen evolution reaction is significantly inhibited. Our study demonstrates an effective approach to develop Cu-based electrocatalysts favourable toward ethanol in electrocatalytic CO₂ reduction.

Keywords:

• Electrocatalytic CO₂ reduction
• hollow Cu₂O nanospheres
• Au_x-Cu₂O composites
• ethanol

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Statement of Retraction

Acknowledgments

I am very grateful to the School of Chemical Engineering and Technology of Tianjin University and my postgraduate research group for providing a good research platform. The experimental part of this article was completed with the support of School of Chemical Engineering and Technology and my research group of Tianjin University. I am very grateful to the teachers and classmates of my graduate research group. I am grateful to the analysis and test center of Tianjin University for providing XRD, SEM, XPS characterizations. Writing, revising, and responding to reviewers' comments of this article was done with the participation of my colleagues and me who are working in SINOPEC Dalian Research Institute of Petroleum and Petrochemicals now. Therefore, the research results of this dissertation also belong to School of Chemical Engineering and Technology of Tianjin University and my postgraduate research group.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary materials

The following are available online at www.mdpi.com/xxx/s1, Figure S1: SEM and TEM images of Au_0.34-Cu₂O composite, Figure S2: SEM and TEM images of Au_0.51-Cu₂O composite, Figure S3: XPS results of Au_0.34-Cu₂O, Figure S4: XPS results of Au_0.51-Cu₂O, Figure S5: XPS results of Cu₂O, Figure S6: Current density and Faraday efficiency of each product of Cu₂O, Figure S7: Current density and Faraday efficiency of each product of Au_0.17-Cu₂O, Figure S8: Current density and Faraday efficiency of each product of Au_0.34-Cu₂O, Figure S9: Current density and Faraday efficiency of each product of Au_0.51-Cu₂O, Table S1: The XPS semiquantitative analysis of Cu₂O and Au_x-Cu₂O.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work is financially supported by SINOPEC (No.112006).

Notes on contributors

Lijie Zhang

Lijie Zhang graduated from Tianjin University. She is working in Dalian Petrochemical Research Institute as an assistant engineer now.

Ying Zhang

Ying Zhang graduated from Tianjin University. She is working in Dalian Petrochemical Research Institute as a professor level senior engineer now.

Hongtao Wang

Hongtao Wang and Jianbing Chen are working in Dalian Petrochemical Research Institute as senior engineers now.

Jianbing Chen

Hongtao Wang and Jianbing Chen are working in Dalian Petrochemical Research Institute as senior engineers now.

Zhongqi Cao

Zhongqi Cao graduated from Beijing University of Chemical Technology. He is woring in Dalian Petrochemical Research Institute as an engineer now.