ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A synergetic graphite-(Ce-montmorillonite) binary composite electrode contains cerium (IV) ions as a supportive electroactive mediator for improved electroanalytical and energy storage applications

D. J. D. S. Gamage, Kohobhange S. P. Karunadasa, and Pannilage M. H. Madhushanka

Department of Environmental and Industrial Sciences, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka

E-mail: sujith@iti.lk

Received: 6 January 2025  Accepted: 20 August 2025

Abstract:

The intercalated clay incorporated graphite composite electrodes will receive an unprecedented attention, as it reveals new composite engineering perspectives. In that sense, a graphite composite electrode is fabricated using cerium intercalated montmorillonite clay (Ce-MMT), obtaining a graphite-(Ce-MMT) composite electrode (G-(Ce-MMT)CE) that exhibits an improved electrochemical performance due to synergetic electrode matrix, in which cerium(IV) ions serve as a supportive electroactive mediator. G-(Ce-MMT)CE analyte response exhibits an ideal cyclic voltammogram signal while resulting in a high sensitivity towards complex inorganic anions than simple cations even though both have similar redox centre, exhibiting ~ 2.0 A m mol⁻¹ sensitivity towards Fe(CN)₆]⁴⁻/[Fe(CN)₆]³⁻ over Fe²⁺/Fe³⁺ that is ~ 0.55 A m mol⁻¹. The polyaniline nanofibers with villi-like surface projections dominantly materialize on G-(Ce-MMT)CE surface during aniline electropolymerization under Ce⁴⁺ intervention, resulting in an interwoven PANI network with low charge transfer (4.1 Ω) and serial resistance (17.8 Ω). The polyaniline-coated G-(Ce-MMT)CE is a potential candidate for supercapacitors, as it attributes to a specific capacitance above 1300 F g⁻¹ while delivering a high energy and power density, which is evident from both cyclic voltammetry and galvanostatic charge–discharge analysis. The pseudocapacitor-like behaviour is dominant with a supercapacitor cell that consists of two identical polyaniline-G-(Ce-MMT)CE segments, as it also accounts for a high coulombic efficiency that indicates a better cyclic stability, ensuring a longer lifespan.

Graphical abstract

Keywords: Graphite; Cerium intercalated MMT; Composite electrode; Electroanalytical applications; Supercapacitors

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04342-8

Chemical Papers 79 (12) 8653–8678 (2025)