Surface activation towards manganese dioxide nanosheet arrays via plasma engineering as cathode and anode for efficient water splitting

Pengcheng Wang; Yaotian Yan; Jian Cao; Jicai Feng; Junlei Qi

doi:10.1016/j.jcis.2020.10.073

Surface activation towards manganese dioxide nanosheet arrays via plasma engineering as cathode and anode for efficient water splitting

J Colloid Interface Sci. 2021 Mar 15:586:95-102. doi: 10.1016/j.jcis.2020.10.073. Epub 2020 Oct 26.

Authors

Pengcheng Wang¹, Yaotian Yan¹, Jian Cao², Jicai Feng¹, Junlei Qi³

Affiliations

¹ State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China.
² School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, China.
³ State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China. Electronic address: jlqi@hit.edu.cn.

PMID: 33162037
DOI: 10.1016/j.jcis.2020.10.073

Abstract

Developing high-efficiency, low-cost electrocatalysts for water splitting is important but challenging. Two-dimensional nanosheet manganese dioxide (MnO₂) arrays are promising candidates for the design and development of advanced catalysts because of their large surface area. Here, a feasible solution to improve the catalytic activity of MnO₂ materials via decorating the active sites on the surface is proposed. With the help of plasma engineering, we successfully enabled surface activity of the MnO₂ nanosheets by decorating P or Fe species together with rich vacancies on the surface. The decorated P (P-MnO₂) or Fe (Fe-MnO₂) species were highly beneficial for the absorption of protons and OH^- respectively, and rich oxygen vacancies induced the formation of stable Mn³⁺, which contributed to electron and charge transfer. Thus, increased electrochemically active specific areas, accelerated charge transfer, and a proper surface electronic structure could be achieved. On the basis of this activation strategy, the fabricated P-MnO₂ and Fe-MnO₂ showed excellent catalytic performance for the hydrogen evolution and oxygen evolution reactions. To our knowledge, the performance of P-MnO₂ and Fe-MnO₂ outperformed most MnO₂-based electrocatalysts in the field of electrocatalytic water splitting. Surface activation of two-dimensional MnO₂ materials by decorating active species via plasma treatment can provide a feasible route for modulating the performance of earth-abundant electrocatalysts for practical applications.

Keywords: Active species; MnO(2); Plasma engineering; Surface activation; Vacancies.