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Developments of nanostructured transition metal dichalcogenides (TMDs) materials as novel electrocatalyst candidates for oxygen reduction reaction (ORR) is a new strategy to promote the developments of non-precious metal ORR catalysts. In this work, a three-dimensional (3D) hybrid of rosebud-like MoSe2 nanostructures supported on reduced graphene oxide (rGO) nanosheets was successfully synthesized through a facile hydrothermal strategy. The prepared MoSe2@rGO hybrid nanostructure showed enhanced electrocatalytic activity for the ORR in alkaline medium compared to that of the pure MoSe2, rGO, and their simple physical mixture, which could benefit from the excellent oxygen adsorption ability of the abundantly exposed active edge sites of the ultrathin MoSe2 layers, the conductivity and aggregation-limiting effect of the rGO platform, as well as the unique 3D rosebud-like architecture of the hybrid material. The electrocatalytic activity of the MoSe2@rGO hybrid towards ORR was comparable to that of commercial Pt/C catalysts. And the promoted reaction was revealed to involve a nearly four-electron-dominated ORR process by analysis of the obtained Koutecky–Levich plots. The scanning electrochemical microscopy (SECM) technique, with the advantages of investigating of the local catalytic activity of samples with high spatial resolution and simultaneously evaluating activities of different catalysts in a single experiment, was further applied to investigate the local ORR electrocatalytic activity of MoSe2@rGO and compare it with those of other catalyst samples through applying different sample potentials. The excellent stability and methanol tolerance of the 3D nanostructured MoSe2@rGO hybrid against methanol further prove the 3D nanostructured MoSe2@rGO hybrid as a promising ORR electrocatalyst in alkaline solution for potential applications in fuel cells and metal–air batteries.


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Visualization of the electrocatalytic activity of three-dimensional MoSe2@reduced graphene oxide hybrid nanostructures for oxygen reduction reaction

Show Author's information Shuli Xin1,§Zhengqing Liu2,§Li Ma1Yao Sun1Chunhui Xiao1Fei Li1,3( )Yaping Du2( )
Department of ChemistrySchool of Science, Xi'an Jiaotong UniversityXi'an710049China
Frontier Institute of Science and Technology jointly with College of ScienceState Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong UniversityXi'an710049China
Bioinspired Engineering and Biomechanics Center (BEBC)Xi'an Jiaotong UniversityXi'an710049China

§ These authors contributed equally to this work.

Abstract

Developments of nanostructured transition metal dichalcogenides (TMDs) materials as novel electrocatalyst candidates for oxygen reduction reaction (ORR) is a new strategy to promote the developments of non-precious metal ORR catalysts. In this work, a three-dimensional (3D) hybrid of rosebud-like MoSe2 nanostructures supported on reduced graphene oxide (rGO) nanosheets was successfully synthesized through a facile hydrothermal strategy. The prepared MoSe2@rGO hybrid nanostructure showed enhanced electrocatalytic activity for the ORR in alkaline medium compared to that of the pure MoSe2, rGO, and their simple physical mixture, which could benefit from the excellent oxygen adsorption ability of the abundantly exposed active edge sites of the ultrathin MoSe2 layers, the conductivity and aggregation-limiting effect of the rGO platform, as well as the unique 3D rosebud-like architecture of the hybrid material. The electrocatalytic activity of the MoSe2@rGO hybrid towards ORR was comparable to that of commercial Pt/C catalysts. And the promoted reaction was revealed to involve a nearly four-electron-dominated ORR process by analysis of the obtained Koutecky–Levich plots. The scanning electrochemical microscopy (SECM) technique, with the advantages of investigating of the local catalytic activity of samples with high spatial resolution and simultaneously evaluating activities of different catalysts in a single experiment, was further applied to investigate the local ORR electrocatalytic activity of MoSe2@rGO and compare it with those of other catalyst samples through applying different sample potentials. The excellent stability and methanol tolerance of the 3D nanostructured MoSe2@rGO hybrid against methanol further prove the 3D nanostructured MoSe2@rGO hybrid as a promising ORR electrocatalyst in alkaline solution for potential applications in fuel cells and metal–air batteries.

Keywords: oxygen reduction reaction, electrocatalyst, MoSe2@rGO hybrid, scanning electrochemical microscopy

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Acknowledgements

Publication history

Received: 15 June 2016
Revised: 21 July 2016
Accepted: 06 August 2016
Published: 17 October 2016
Issue date: December 2016

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© Tsinghua University Press and Springer-Verlag Berlin Heidelberg 2016

Acknowledgements

Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (Nos. 21105079 and 21405119), the Fundamental Research Funds for the Central Universities of China (Nos. 0109-1191320016 and cxtd2015003), the Scientific Research Foundation for the Returned Overseas Chinese Scholars by the State Education Ministry of China, and the International Science and Technology Cooperation and Exchange Program of Shaanxi Province of China (No. 2016KW-064). Yaping Du gratefully acknowledges the financial support from the start-up funding from Xi'an Jiaotong University, the Fundamental Research Funds for the Central Universities of China (No. 2015qngz12), and the the National Natural Science Foundation of China (Nos. 21522106 and 21371140).

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