{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:43:34Z","timestamp":1787028214717,"version":"build-2736575974"},"reference-count":37,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2024,3,28]],"date-time":"2024-03-28T00:00:00Z","timestamp":1711584000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Romanian Ministry of Research and Innovation, CCCDI\u2014UEFISCDI","award":["PN-III-P1-1.2-PCCDI-2017-0350\/01.03.2018"],"award-info":[{"award-number":["PN-III-P1-1.2-PCCDI-2017-0350\/01.03.2018"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Gels"],"abstract":"<jats:p>In this study, bismuth- and iron-embedded carbon xerogels (XG) were obtained using a modified resorcinol formaldehyde sol\u2013gel synthesis method followed by additional enrichment with iron content. Pyrolysis treatment was performed at elevated temperatures under Ar or N2 atmosphere to obtain nanocomposites with different reduction yields (XGAr or XGN). The interest was focused on investigating the extent to which changes in the pyrolysis atmosphere of these nanocomposites impact the structure, morphology, and electrical properties of the material and consequently affect the electroanalytical performance. The structural and morphological particularities derived from X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) measurements revealed the formation of the nanocomposite phases, mostly metal\/oxide components. The achieved performances for the two modified electrodes based on XG treated under Ar or N2 atmosphere clearly differ, as evidenced by the electroanalytical parameters determined from the detection of heavy metal cations (Pb2+) or the use of the square wave voltammetry (SWV) technique, biomarkers (H2O2), or amperometry. By correlating the differences obtained from electroanalytical measurements with those derived from morphological, structural, and surface data, a few utmost important aspects were identified. Pyrolysis under Ar atmosphere favors a significant increase in the \u03b1-Fe2O3 amount and H2O2 detection performance (sensitivity of 0.9 A\/M and limit of detection of 0.17 \u03bcM) in comparison with pyrolysis under N2 (sensitivity of 0.5 A\/M and limit of detection of 0.36 \u03bcM), while pyrolysis under N2 atmosphere leads to an increase in the metallic Bi amount and Pb2+ detection performance (sensitivity of 8.44 \u00d7 103 A\/M and limit of detection of 33.05 pM) in comparison with pyrolysis under Ar (sensitivity of 6.47\u00b7103 A\/M and limit of detection of 46.37 pM).<\/jats:p>","DOI":"10.3390\/gels10040230","type":"journal-article","created":{"date-parts":[[2024,3,28]],"date-time":"2024-03-28T12:22:46Z","timestamp":1711628566000},"page":"230","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["The Impact of Ar or N2 Atmosphere on the Structure of Bi-Fe-Carbon Xerogel Based Composites as Electrode Material for Detection of Pb2+ and H2O2"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4675-7602","authenticated-orcid":false,"given":"Carmen I.","family":"Fort","sequence":"first","affiliation":[{"name":"Faculty of Chemistry and Chemical Engineering, \u201cBabes-Bolyai\u201d University, Arany Janos 11, RO-400028 Cluj-Napoca, Romania"},{"name":"Institute for Research-Development-Innovation in Applied Natural Sciences, \u201cBabes-Bolyai\u201d University, F\u00e2nt\u00e2nele 30, RO-400294 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6760-7320","authenticated-orcid":false,"given":"Mihai M.","family":"Rusu","sequence":"additional","affiliation":[{"name":"Institute for Research-Development-Innovation in Applied Natural Sciences, \u201cBabes-Bolyai\u201d University, F\u00e2nt\u00e2nele 30, RO-400294 Cluj-Napoca, Romania"},{"name":"Institute of Interdisciplinary Research in Bio-Nano-Sciences, \u201cBabes-Bolyai\u201d University, T. Laurean 42, RO-400271 Cluj-Napoca, Romania"},{"name":"Faculty of Physics, \u201cBabes-Bolyai\u201d University, M. Kogalniceanu 1, RO-400084 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liviu C.","family":"Cotet","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Chemical Engineering, \u201cBabes-Bolyai\u201d University, Arany Janos 11, RO-400028 Cluj-Napoca, Romania"},{"name":"Institute for Research-Development-Innovation in Applied Natural Sciences, \u201cBabes-Bolyai\u201d University, F\u00e2nt\u00e2nele 30, RO-400294 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adriana","family":"Vulpoi","sequence":"additional","affiliation":[{"name":"Institute of Interdisciplinary Research in Bio-Nano-Sciences, \u201cBabes-Bolyai\u201d University, T. Laurean 42, RO-400271 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8958-4035","authenticated-orcid":false,"given":"Milica","family":"Todea","sequence":"additional","affiliation":[{"name":"Institute of Interdisciplinary Research in Bio-Nano-Sciences, \u201cBabes-Bolyai\u201d University, T. Laurean 42, RO-400271 Cluj-Napoca, Romania"},{"name":"Faculty of Medicine, \u201cIuliu Ha\u0163ieganu\u201d University of Medicine and Pharmacy, Victor Babe\u0219 8, RO\u2013400012 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6820-2491","authenticated-orcid":false,"given":"Monica","family":"Baia","sequence":"additional","affiliation":[{"name":"Institute for Research-Development-Innovation in Applied Natural Sciences, \u201cBabes-Bolyai\u201d University, F\u00e2nt\u00e2nele 30, RO-400294 Cluj-Napoca, Romania"},{"name":"Faculty of Physics, \u201cBabes-Bolyai\u201d University, M. Kogalniceanu 1, RO-400084 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3196-4868","authenticated-orcid":false,"given":"Lucian","family":"Baia","sequence":"additional","affiliation":[{"name":"Institute for Research-Development-Innovation in Applied Natural Sciences, \u201cBabes-Bolyai\u201d University, F\u00e2nt\u00e2nele 30, RO-400294 Cluj-Napoca, Romania"},{"name":"Institute of Interdisciplinary Research in Bio-Nano-Sciences, \u201cBabes-Bolyai\u201d University, T. Laurean 42, RO-400271 Cluj-Napoca, Romania"},{"name":"Faculty of Physics, \u201cBabes-Bolyai\u201d University, M. Kogalniceanu 1, RO-400084 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,3,28]]},"reference":[{"key":"ref_1","unstructured":"Fort, C.I., and Pop, L.C. (2020). 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