Interfacial Phenomena Governing Performance of Graphene Electrodes in Aqueous Electrolyte Delgà-Fernández, Marta Toral López, Alejandro González Marín, Enrique Godoy Medina, Andrés M.D.-F. acknowledges that this work has been done within the framework of the Ph.D. program in Materials Science of the Autonomous University of Barcelona. This work has received funding from the Spanish State Research Agency through PRE2018-086251 funded by MCIN/AEI/10.13039/501100011033 and FSE, UE, the PID2020-113663RB-I00 funded by MCIN/AEI/10.13039/501100011033 and the European Union’s Horizon 2020 research and innovation programs under Grant Agreement No. 881603 (Graphene Flagship Core Project 3). This work is supported by the Generalitat de Catalunya (2021-SGR-01534) and the Spanish Government through Project PID2020-116518GB-I00 funded by MCIN/AEI/10.13039/501100011033 and Project TED2021-129769B-I00 funded by MCIN/AEI/10.13039/501100011033 by the European Union NextGenerationEU/PRTR. Part of this work has made use of the Spanish ICTS Network MICRONANOFABS, partially supported by MICINN and the ICTS NANBIOSIS, more specifically, by the MicroNanoTechnology Unit U8 of the CIBER-BBN. This project has also been funded by the Generalitat de Catalunya (2021SGR00495), by the Spanish Ministerio de Ciencia e Innovación (PID2021-126117NA-I00, PLEC2022-009232,), and by CIBER-BBN (CB06/01/0049). E.d.C. acknowledges the RYC2019-027879-I Grant funded by MCIN/AEI/10.13039/501100011033. There is evidence of the presence of intercalated water between graphene and the substrate in electronic devices. However, a proper understanding of the impact of this phenomenon, which causes important limitations for the optimization of graphene-based devices operating in aqueous electrolytes, is missing. We used graphene-based electrodes on insulating and conducting substrates to evaluate the impact of intercalated water by combining experimental techniques with numerical simulations. Results show that the capacitance of the conductive substrate/graphene electrodes is significantly higher than that of the insulating substrate/graphene ones. Meanwhile, Raman spectroscopy demonstrates that graphene charge modulation with the applied potential is independent of the substrate conductivity. We found that this intriguing behavior is influenced by the water intercalation phenomena and governed by the substrate conductive nature. This work contributes to the understanding of the electric response of graphene-based devices in an aqueous environment and of the methods to measure and model it. 2025-01-28T14:11:21Z 2025-01-28T14:11:21Z 2024-08-04 journal article Delgà-Fernández, Marta et al. Interfacial Phenomena Governing Performance of Graphene Electrodes in Aqueous Electrolyte. Nano Lett. 2024, 24, 11376−11384. doi:10.1021/acs.nanolett.4c01808 https://hdl.handle.net/10481/100834 10.1021/acs.nanolett.4c01808 eng info:eu-repo/grantAgreement/EC/H2020/881603 http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional American Chemical Society