Pseudocapacitive Hausmannite Nanoparticles with (101) Facets: Synthesis, Characterization, and Charge‐Transfer Mechanism. Issue 10 (3rd May 2013)

• Record Type: Journal Article
• Authors: Yeager, Matthew P.; Du, Wenxin; Wang, Qi; Deskins, N. Aaron; Sullivan, Matthew; Bishop, Brendan; Su, Dong; Xu, Wenqian; Senanayake, Sanjaya D.; Si, Rui; Hanson, Jonathan; Teng, Xiaowei
• Is Part Of: ChemSusChem. Volume 6:Issue 10(2013:Oct.)
• Page Start: 1983
• Page End: 1992
• Publication Date: 2013-05-03
• Subjects: Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201300027
• Languages: English
• ISSNs: 1864-5631

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Hausmannite Mn₃O₄ octahedral nanoparticles of 18.3±7.0 nm with (101) facets have been prepared by an oxygen‐mediated growth. The electrochemical properties of the Mn₃O₄ particles as pseudocapacitive cathode materials were characterized both in half‐cells and in button‐cells. The Mn₃O₄ nanoparticles exhibited a high mass‐specific capacitance of 261 F g⁻¹, which was calculated from cyclic voltammetry analyses, and a capacitive retention of 78 % after 10 000 galvanostatic charge–discharge cycles. The charge‐transfer mechanisms of the Mn₃O₄ nanoparticles were further studied by using synchrotron‐based in situ X‐ray absorption near edge spectroscopy and XRD. Both measurements showed concurrently that throughout the potential window of 0–1.2 V (vs. Ag/AgCl), a stable spinel structure of Mn₃O₄ remained, and a reversible electrochemical conversion between tetrahedral [Mn^IIO₄] and octahedral [Mn^IIIO₆] units accounted for the redox activity. Density functional theory calculations further corroborated this mechanism by confirming the enhanced redox stability afforded by the abundant and exposed (101) facets of Mn₃O₄ octahedra.</p> </abstract>