Eur. Phys. J. Plus (2020) 135: 329
https://doi.org/10.1140/epjp/s13360-020-00333-8

Regular Article

In situ atomic force microscopy: the case study of graphite immersed in aqueous NaOH electrolyte

¹ Department of Physics, Politecnico di Milano, p.za L. da Vinci 32, 20133, Milan, Italy
² Department of Earth and Environmental Sciences, Università degli Studi di Milano-Bicocca, Piazza della Scienza 4, 20126, Milan, Italy
³ Istituto di Scienze e Tecnologie Chimiche “G. Natta” of the CNR (CNR-SCITEC) and SmartMatLab Center, Consiglio Nazionale delle Ricerche, Via Golgi 19, 20133, Milan, Italy
⁴ Dipartimento di Fisica, Università degli Studi di Roma “Tor Vergata”, v. della Ricerca Scientifica 1, 00133, Rome, Italy

^* e-mail: alberto.bossi@cnr.it

Received: 18 November 2019
Accepted: 13 March 2020
Published online: 26 March 2020

Abstract

In situ atomic force microscopy (AFM) measures, with the scanner head immersed inside a liquid (namely an electrolyte), are—generally speaking—not easy to be acquired in real time, i.e., during electrochemical processes, the immersion of a massive and wide system (with respect to the electrochemical cell mean radius) can significantly perturb the electrolyte and the I/V profile of the electrochemical characterization (CV). Despite this fact, the information that can be obtained from an electrode morphological inspection is very precious, and the coupling between an AFM and an electrochemical cell is in any case successful. In this work, we discuss the surface morphological evolution of a graphite electrode when immersed inside an aqueous NaOH electrolyte. 1.0 M sodium hydroxide added inside electrochemical baths was shown to promote the intercalation of ions between the stratified graphite structure or graphene layers. Possible consequences of diluted NaOH electrolyte on the quality of the graphite basal plane have been never considered in detail yet. By means of an in situ AFM, we show the effects of CVs on the surface morphology of the graphite basal plane. Our result shows that a 1.0 M NaOH solution, generally used for promoting intercalation, changes the electrode surface quality as a consequence of a partial carbon corrosion.