Carbon recovered from Li-ion batteries for methylene blue adsorption: waste valorization toward environmental remediation

Carbon recovered from Li-ion batteries for methylene blue adsorption: waste valorization toward environmental remediation | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Short Report Carbon recovered from Li-ion batteries for methylene blue adsorption: waste valorization toward environmental remediation Eric M. Garcia, Hosane Taroco, Julio Melo This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8583947/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 23 You are reading this latest preprint version Abstract Graphitic carbon recovered from spent lithium-ion battery anodes was repurposed as a low-cost adsorbent for methylene blue removal from aqueous solutions, demonstrating a practical waste-valorization strategy. Adsorption was strongly pH-dependent, with the highest performance achieved at pH 11, where the Langmuir model showed excellent agreement (R² = 0.998) and a maximum adsorption capacity of 7.25 mg·g⁻¹. Isotherm analysis revealed an energetically heterogeneous surface, with adsorption becoming more distributed at neutral and alkaline pH. Thermodynamic evaluation confirmed a spontaneous, entropy-driven process governed predominantly by physisorption, as indicated by a small negative enthalpy change (ΔH° = −6.64 ± 0.47 kJ·mol⁻¹), negative Gibbs free energy values, and a positive entropy change. The adsorbent retained over 90% of its initial efficiency after seven regeneration cycles using dilute acid, highlighting its reusability. Overall, recycled graphitic carbon emerges as a simple, reusable, and environmentally friendly alternative for dye-contaminated wastewater treatment. Li-ion battery Recycling Spent anode Methylene blue Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 31 Mar, 2026 Reviews received at journal 03 Mar, 2026 Reviews received at journal 02 Mar, 2026 Reviews received at journal 28 Feb, 2026 Reviews received at journal 27 Feb, 2026 Reviews received at journal 25 Feb, 2026 Reviewers agreed at journal 25 Feb, 2026 Reviewers agreed at journal 20 Feb, 2026 Reviewers agreed at journal 20 Feb, 2026 Reviewers agreed at journal 20 Feb, 2026 Reviewers agreed at journal 19 Feb, 2026 Reviewers agreed at journal 19 Feb, 2026 Reviewers agreed at journal 19 Feb, 2026 Reviews received at journal 07 Feb, 2026 Reviewers agreed at journal 02 Feb, 2026 Reviewers agreed at journal 29 Jan, 2026 Reviews received at journal 25 Jan, 2026 Reviewers agreed at journal 24 Jan, 2026 Reviewers invited by journal 20 Jan, 2026 Editor invited by journal 19 Jan, 2026 Editor assigned by journal 16 Jan, 2026 Submission checks completed at journal 16 Jan, 2026 First submitted to journal 12 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8583947","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Short Report","associatedPublications":[],"authors":[{"id":577570200,"identity":"e725d909-869d-419e-8a19-7d978c62f790","order_by":0,"name":"Eric M. 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