{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T22:25:01Z","timestamp":1776723901670,"version":"3.51.2"},"reference-count":23,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2019,12,14]],"date-time":"2019-12-14T00:00:00Z","timestamp":1576281600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"VEKOP","award":["VEKOP-2.3.2-16-2017-00013"],"award-info":[{"award-number":["VEKOP-2.3.2-16-2017-00013"]}]},{"name":"H2020-MSCA-RISE-","award":["734641"],"award-info":[{"award-number":["734641"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>The potential applications of mesoporous carbon aerogels are wide-ranging. These gels are often obtained from resorcinol-formaldehyde (RF) hydrogel precursors. The sol-gel method in this synthesis provides an efficient and versatile means of product control through systematic variation of process conditions, such as pH, stoichiometry, concentration, catalyst, further additives, etc., in addition to the drying and pyrolytic conditions. Here, a novel means of tuning the texture of carbon aerogels is proposed. Water-1-ethyl-3-methylimidazolium ethyl sulfate ([emim][EtSO4] mixtures constitutes a polycondensation medium that requires no added catalyst, thus yielding an intrinsically metal-free carbon aerogel after pyrolysis. We also show that the carbon morphology is tailored by the supramolecular structure of the aqueous ionic liquid. The results of scanning electron micrographs, low-temperature nitrogen adsorption\/desorption isotherms, and small-angle X-ray scattering (SAXS) confirm that changing the initial water concentration from 9 to 55 wt % gives rise to systematic alteration of the mesopore size and volume, as well as of the bead size. The pore structure becomes consolidated only when the water content exceeds 25 wt %. When the water content reaches 55 wt %, the bead size increases by two orders of magnitude. The electrocatalytic performance, however, is compromised, most probably by structural defects.<\/jats:p>","DOI":"10.3390\/ma12244208","type":"journal-article","created":{"date-parts":[[2019,12,16]],"date-time":"2019-12-16T05:19:38Z","timestamp":1576473578000},"page":"4208","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Water-Ionic Liquid Binary Mixture Tailored Resorcinol-Formaldehyde Carbon Aerogels without Added Catalyst"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2593-1034","authenticated-orcid":false,"given":"Bal\u00e1zs","family":"Nagy","sequence":"first","affiliation":[{"name":"Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, H-1521 Budapest, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Istv\u00e1n","family":"Bakos","sequence":"additional","affiliation":[{"name":"Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, E\u00f6tv\u00f6s Lor\u00e1nd Research Network, H-1519 Budapest, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Erik","family":"Geissler","sequence":"additional","affiliation":[{"name":"Laboratoire Interdisciplinaire de Physique, Universit\u00e9 Grenoble Alpes and CNRS, 38402 Grenoble Cedex, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4499-3983","authenticated-orcid":false,"given":"Krisztina","family":"L\u00e1szl\u00f3","sequence":"additional","affiliation":[{"name":"Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, H-1521 Budapest, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,12,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3221","DOI":"10.1007\/BF01139044","article-title":"Organic aerogels from the polycondensation of resorcinol with formaldehyde","volume":"24","author":"Pekala","year":"1989","journal-title":"J. Mater. Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2887","DOI":"10.1002\/adma.201100283","article-title":"Advances in Tailoring Resorcinol-Formaldehyde Organic and Carbon Gels","volume":"23","author":"ElKhatat","year":"2012","journal-title":"Adv. Mater."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Arenillas, A., Men\u00e9ndez, J.A., Reichenauer, G., Celzard, A., Fierro, V., Maldonado-Hodar, F.J., Bail\u03ccn-Garcia, E., and Job, N. (2019). Organic and Carbon Gels. From Laboratory Synthesis to Applications. Book Series: Advances in Sol-Gel Derived Materials and Technologies, Springer.","DOI":"10.1007\/978-3-030-13897-4"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.jnoncrysol.2005.11.024","article-title":"Synthesis optimization of organic xerogels produced from convective air-drying of resorcinol-formaldehyde gels","volume":"352","author":"Job","year":"2006","journal-title":"J. Non-Cryst. Solids"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"619","DOI":"10.1016\/j.carbon.2003.12.072","article-title":"Porous carbon xerogels with texture tailored by pH control during sol-gel process","volume":"42","author":"Job","year":"2004","journal-title":"Carbon"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.micromeso.2015.06.003","article-title":"The enhancement of porosity of carbon xerogels by using additives","volume":"217","author":"Calvo","year":"2015","journal-title":"Microporous Mesoporous Mater."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.micromeso.2005.07.021","article-title":"Influence of Drying on the Morphology of Resorcinol-Formaldehyde-based Carbon Gels","volume":"86","author":"Czakkel","year":"2005","journal-title":"Microporous Mesoporous Mater."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1016\/j.supflu.2012.12.027","article-title":"In-situ investigation of the structural changes of resorcinol-formaldehyde polymer gels during CO2-drying","volume":"75","author":"Czakkel","year":"2013","journal-title":"J. Supercrit. Fluids"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"7190","DOI":"10.1021\/acs.chemrev.6b00504","article-title":"Application of Ionic Liquids to Energy Storage and Conversion Materials and Devices","volume":"117","author":"Watanabe","year":"2017","journal-title":"Chem. Rev."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1469","DOI":"10.1039\/C3CC48942F","article-title":"Ionic liquid derived carbons as highly efficient oxygen reduction catalysts: First elucidation of pore size distribution dependent kinetics","volume":"50","author":"Zhang","year":"2014","journal-title":"Chem. Commun."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1002\/adma.201203422","article-title":"\u201cSalt Templating\u201d: A Simple and Sustainable Pathway toward Highly Porous Functional Carbons from Ionic Liquids","volume":"25","author":"Fechler","year":"2013","journal-title":"Adv. Mater."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"7434","DOI":"10.1039\/c1jm00013f","article-title":"Hierarchical porous carbonaceous materials via ionothermal carbonization of carbohydrates","volume":"21","author":"Xie","year":"2011","journal-title":"J. Mater. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"21852","DOI":"10.1039\/c2jm35258c","article-title":"Ionic liquid templated preparation of carbon aerogels based on resorcinol\u2013formaldehyde: Properties and catalytic performance","volume":"22","author":"Yang","year":"2012","journal-title":"J. Mater. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1813","DOI":"10.1007\/s10008-016-3170-2","article-title":"Synthesis of mesoporous carbon aerogels based on metal-containing ionic liquid and its application for electrochemical capacitors","volume":"20","author":"Sun","year":"2016","journal-title":"J. Solid State Electrochem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/j.apsusc.2016.10.025","article-title":"Controllable synthesis of nitrogen-doped hollow mesoporous carbon spheres using ionic liquids as template for supercapacitors","volume":"393","author":"Chen","year":"2017","journal-title":"Appl. Surf. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Nagy, B., Geissler, E., and L\u00e1szl\u00f3, K. (2019). Room temperature ionic liquids to tailor resorcinol-formaldehyde polymer gels. Microporous Mesoporous Mater.","DOI":"10.1016\/j.micromeso.2019.109888"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"872","DOI":"10.1016\/j.carbon.2018.07.061","article-title":"Synergism of melamine and GO in the electrocatalytic behaviour of resorcinol-formaldehyde based carbon aerogels","volume":"139","author":"Nagy","year":"2018","journal-title":"Carbon"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.elecom.2013.02.022","article-title":"Ionic liquid as template to synthesize carbon xerogels by coupling with KOH activation for supercapacitors","volume":"31","author":"Wang","year":"2013","journal-title":"Electrochem. Commun."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1051","DOI":"10.1515\/pac-2014-1117","article-title":"Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report)","volume":"87","author":"Thommes","year":"2015","journal-title":"Pure Appl. Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1321","DOI":"10.1021\/la035954s","article-title":"Morphological Investigation of chemically treated PET based activated carbons","volume":"20","author":"Marthi","year":"2004","journal-title":"Langmuir"},{"key":"ref_21","unstructured":"Glatter, O., and Kratky, O. (1982). In Small-Angle X-ray Scattering, Academic Press."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3324","DOI":"10.1016\/j.carbon.2011.12.047","article-title":"Electrochemical performance of carbon gels with variable surface chemistry and physics","volume":"50","author":"Dawidziuk","year":"2012","journal-title":"Carbon"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.micromeso.2016.05.009","article-title":"Nitrogen doped mesoporous carbon aerogels and implications for electrocatalytic oxygen reduction reactions","volume":"230","author":"Nagy","year":"2016","journal-title":"Microporous Mesoporous Mater."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/12\/24\/4208\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:42:24Z","timestamp":1760190144000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/12\/24\/4208"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,12,14]]},"references-count":23,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2019,12]]}},"alternative-id":["ma12244208"],"URL":"https:\/\/doi.org\/10.3390\/ma12244208","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,12,14]]}}}