{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T23:07:23Z","timestamp":1792796843212,"version":"4.5.0"},"reference-count":71,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,6,10]],"date-time":"2025-06-10T00:00:00Z","timestamp":1749513600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Operational Program \u201cScience and Education for Smart Growth\u201d 2021\u20132027","award":["BG16RFPR002-1.014-0009"],"award-info":[{"award-number":["BG16RFPR002-1.014-0009"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Gels"],"abstract":"<jats:p>The aim of this study is to explore the feasibility of using flotation wastewater from copper\u2013porphyry ore processing to synthesize a gel that serves as a precursor for a polymer nanocomposite used in supercapacitor electrode fabrication. These wastewaters\u2014characterized by high acidity and elevated concentrations of metal cations (Cu, Ni, Zn, Fe), sulfates, and organic reagents such as xanthates, oil (20 g\/t ore), flotation frother (methyl isobutyl carbinol), and pyrite depressant (CaO, 500\u20131000 g\/t), along with residues from molybdenum flotation (sulfuric acid, sodium hydrosulfide, and kerosene)\u2014are byproducts of copper\u2013porphyry gold-bearing ore beneficiation. The reduction of Ni powder in the wastewater induces the degradation and formation of a gel that captures both residual metal ions and organic compounds\u2014particularly xanthates\u2014which play a crucial role in the subsequent steps. The resulting gel is incorporated during the oxidative polymerization of aniline, forming a nanocomposite with a polyaniline matrix and embedded xanthate-based compounds. An asymmetric supercapacitor was assembled using the synthesized material as the cathodic electrode. Electrochemical tests revealed remarkable capacitance and cycling stability, demonstrating the potential of this novel approach both for the valorization of industrial waste streams and for enhancing the performance of energy storage devices.<\/jats:p>","DOI":"10.3390\/gels11060446","type":"journal-article","created":{"date-parts":[[2025,6,10]],"date-time":"2025-06-10T08:18:43Z","timestamp":1749543523000},"page":"446","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Utilization of Flotation Wastewater for Metal Xanthate Gel Synthesis and Its Role in Polyaniline-Based Supercapacitor Electrode Fabrication"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-1068-4923","authenticated-orcid":false,"given":"Atanas","family":"Garbev","sequence":"first","affiliation":[{"name":"\u201cAcad. Evgeni Budevski\u201d Institute of Electrochemistry and Energy Systems (IEES), Bulgarian Academy of Sciences (BAS), Acad. G. Bonchev Str., bl. 10, 1113 Sofia, Bulgaria"},{"name":"Center of Competence \u201cHITMOBIL\u201d, (CoC) Acad. G. Bonchev Str. 10, 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9370-6448","authenticated-orcid":false,"given":"Elitsa","family":"Petkucheva","sequence":"additional","affiliation":[{"name":"\u201cAcad. Evgeni Budevski\u201d Institute of Electrochemistry and Energy Systems (IEES), Bulgarian Academy of Sciences (BAS), Acad. G. Bonchev Str., bl. 10, 1113 Sofia, Bulgaria"},{"name":"Center of Competence \u201cHITMOBIL\u201d, (CoC) Acad. G. Bonchev Str. 10, 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Galia","family":"Ivanova","sequence":"additional","affiliation":[{"name":"\u201cAcad. Evgeni Budevski\u201d Institute of Electrochemistry and Energy Systems (IEES), Bulgarian Academy of Sciences (BAS), Acad. G. Bonchev Str., bl. 10, 1113 Sofia, Bulgaria"},{"name":"Center of Competence \u201cHITMOBIL\u201d, (CoC) Acad. G. Bonchev Str. 10, 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6389-3668","authenticated-orcid":false,"given":"Mariela","family":"Dimitrova","sequence":"additional","affiliation":[{"name":"\u201cAcad. Evgeni Budevski\u201d Institute of Electrochemistry and Energy Systems (IEES), Bulgarian Academy of Sciences (BAS), Acad. G. Bonchev Str., bl. 10, 1113 Sofia, Bulgaria"},{"name":"Center of Competence \u201cHITMOBIL\u201d, (CoC) Acad. G. Bonchev Str. 10, 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonia","family":"Stoyanova","sequence":"additional","affiliation":[{"name":"\u201cAcad. Evgeni Budevski\u201d Institute of Electrochemistry and Energy Systems (IEES), Bulgarian Academy of Sciences (BAS), Acad. G. Bonchev Str., bl. 10, 1113 Sofia, Bulgaria"},{"name":"Center of Competence \u201cHITMOBIL\u201d, (CoC) Acad. G. Bonchev Str. 10, 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Evelina","family":"Slavcheva","sequence":"additional","affiliation":[{"name":"\u201cAcad. Evgeni Budevski\u201d Institute of Electrochemistry and Energy Systems (IEES), Bulgarian Academy of Sciences (BAS), Acad. G. Bonchev Str., bl. 10, 1113 Sofia, Bulgaria"},{"name":"Center of Competence \u201cHITMOBIL\u201d, (CoC) Acad. G. Bonchev Str. 10, 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,10]]},"reference":[{"key":"ref_1","unstructured":"Conway, B.E. (1999). Electrochemical Supercapacitors: Scientific Fundamentals and Technological Applications, Springer."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"651","DOI":"10.1126\/science.1158736","article-title":"Materials science: Electrochemical capacitors for energy management","volume":"321","author":"Miller","year":"2008","journal-title":"Science"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"100690","DOI":"10.1016\/j.ceja.2024.100690","article-title":"Recent advancement and design in supercapacitor hybrid electrode materials: Bridging the gap between energy and power density","volume":"21","author":"Mandal","year":"2025","journal-title":"Chem. Eng. J. Adv."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"4644","DOI":"10.1039\/C9NA00543A","article-title":"Metal oxide-based supercapacitors: Progress and challenges","volume":"1","author":"An","year":"2019","journal-title":"Nanoscale Adv."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Kamal, N., Choudhury, A., and Mahapatra, S.S. (2025). Advances in conducting polymer-Based electrodes for supercapacitors: A focus on binder-free integration. J. Macromol. Sci. Part A, 1\u201318.","DOI":"10.1080\/10601325.2025.2498120"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1151","DOI":"10.1038\/s41563-020-0747-z","article-title":"Perspectives for electrochemical capacitors and related devices","volume":"19","author":"Simon","year":"2020","journal-title":"Nat. Mater."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"4343","DOI":"10.1002\/celc.201900668","article-title":"Review on Recent Progress in Ruthenium Oxide-Based Composites for Supercapacitor Applications","volume":"6","author":"Majumdar","year":"2019","journal-title":"ChemElectroChem"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1016\/j.jpowsour.2006.04.012","article-title":"Nanostructured MnO2: Hydrothermal synthesis and electrochemical properties as a supercapacitor electrode material","volume":"159","author":"Subramanian","year":"2006","journal-title":"J. Power Sources"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/j.coelec.2020.02.004","article-title":"Recent progress in nickel oxide-based electrodes for high-performance supercapacitors","volume":"21","author":"Chime","year":"2020","journal-title":"Curr. Opin. Electrochem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1016\/j.jallcom.2017.07.145","article-title":"A robust solvent deficient route synthesis of mesoporous Fe2O3 nanoparticles as supercapacitor electrode material with improved capacitive performance","volume":"725","author":"Kore","year":"2017","journal-title":"J. Alloys Compd."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"101995","DOI":"10.1016\/j.est.2020.101995","article-title":"Recent advancements of copper oxide based nanomaterials for supercapacitor applications","volume":"34","author":"Majumdar","year":"2021","journal-title":"J. Energy Storage"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1002\/slct.201702780","article-title":"Zinc Oxide Based Composite Materials for Advanced Supercapacitors","volume":"3","author":"Wang","year":"2018","journal-title":"ChemistrySelect"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/j.jpowsour.2011.12.057","article-title":"Interfacial synthesis of mesoporous MnO2\/polyaniline hollow spheres and their application in electrochemical capacitors","volume":"204","author":"Wang","year":"2012","journal-title":"J. Power Sources"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2520","DOI":"10.1039\/b813846j","article-title":"Carbon-based materials as supercapacitor electrodes","volume":"38","author":"Zhang","year":"2009","journal-title":"Chem. Soc. Rev."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1664","DOI":"10.1016\/j.physb.2009.01.046","article-title":"Effect of molybdenum trioxide (MoO3) on the electrical conductivity of polyaniline","volume":"404","author":"Anilkumar","year":"2009","journal-title":"Phys. B Condens. Matter"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e202401222","DOI":"10.1002\/asia.202401222","article-title":"From Waste to Power: Developing Structural Supercapacitors with Red Mud and Jute Stick","volume":"20","author":"Nor","year":"2025","journal-title":"Chem. Asian J."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Soulamidis, G., Kourmousi, M., Mitsopoulou, C.A., and Stouraiti, C. (2024). Electrochemical Behavior of Natural Manganese Oxides: Transforming Mining Waste into Energy Storage Materials. Minerals, 14.","DOI":"10.3390\/min14050455"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1177\/0734242X19826776","article-title":"Circular economy, recycling and end-of-waste","volume":"37","author":"Ragossnig","year":"2019","journal-title":"Waste Manag. Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"100232","DOI":"10.1016\/j.wroa.2024.100232","article-title":"Making waves: Xanthates on the radar\u2014Environmental risks and water quality impact","volume":"24","author":"Duarte","year":"2024","journal-title":"Water Res. X"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Yuan, J., Li, S., Ding, Z., Li, J., Yu, A., Wen, S., and Bai, S. (2023). Treatment Technology and Research Progress of Residual Xanthate in Mineral Processing Wastewater. Minerals, 13.","DOI":"10.3390\/min13030435"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"5698","DOI":"10.1016\/j.jmrt.2019.09.037","article-title":"Degradation of xanthate in waters by hydrogen peroxide, fenton and simulated solar photo-fenton processes","volume":"8","author":"Teixeira","year":"2019","journal-title":"J. Mater. Res. Technol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1016\/j.jclepro.2016.08.027","article-title":"Oxidation of potassium n-butyl xanthate with ozone: Products and pathways","volume":"139","author":"Yan","year":"2016","journal-title":"J. Clean. Prod."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1069","DOI":"10.1002\/cjce.23705","article-title":"Degradation of surfactant used in iron mining by oxidation technique: Fenton, photo-Fenton, and H2O2\/UV\u2014A comparative study","volume":"98","author":"Falconi","year":"2020","journal-title":"Can. J. Chem. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"141626","DOI":"10.1016\/j.jclepro.2024.141626","article-title":"Electrochemical oxidation degradation of xanthate and its mechanism: Effects of carbon chain length and electrolyte type","volume":"448","author":"Bao","year":"2024","journal-title":"J. Clean. Prod."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"106130","DOI":"10.1016\/j.jwpe.2024.106130","article-title":"Evolution of photocatalysis process for degradation of residual xanthate in wastewater from mineral processing industry\u2014A review","volume":"67","author":"Raj","year":"2024","journal-title":"J. Water Process Eng."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"126273","DOI":"10.1016\/j.colsurfa.2021.126273","article-title":"Xanthate modified magnetic activated carbon for efficient removal of cationic dyes and tetracycline hydrochloride from aqueous solutions","volume":"615","author":"Yang","year":"2021","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"\u0160tulovi\u0107, M., Radovanovi\u0107, D., Diki\u0107, J., Gaji\u0107, N., Djoki\u0107, J., Kamberovi\u0107, \u017d., and Jevti\u0107, S. (2024). Utilization of Copper Flotation Tailings in Geopolymer Materials Based on Zeolite and Fly Ash. Materials, 17.","DOI":"10.3390\/ma17246115"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"120300","DOI":"10.1016\/j.envres.2024.120300","article-title":"Adsorption and biodegradation of butyl xanthate in mine water by Pseudomonas sp. immobilized on yak dung biochar","volume":"264","author":"Shan","year":"2025","journal-title":"Environ. Res."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Qi, Y., Zhao, S., Shen, Y., Jiang, X., Lv, H., Han, C., Liu, W., and Zhao, Q. (2024). A Critical Review of Clay Mineral-Based Photocatalysts for Wastewater Treatment. Catalysts, 14.","DOI":"10.3390\/catal14090575"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.mineng.2018.01.012","article-title":"Removal of the residual xanthate from flotation plant tailings using modified bentonite","volume":"119","author":"Rezaei","year":"2018","journal-title":"Miner. Eng."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"14890","DOI":"10.1039\/C4TA02570A","article-title":"Mesoporous silica nanoparticles for high capacity adsorptive desulfurization","volume":"2","author":"Palomino","year":"2014","journal-title":"J. Mater. Chem. A"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/j.gsme.2024.03.003","article-title":"Photocatalytic degradation of xanthates under visible light using heterogeneous CuO\/TiO2\/montmorillonite composites","volume":"1","author":"Zhao","year":"2024","journal-title":"Green Smart Min. Eng."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"108308","DOI":"10.1016\/j.mineng.2023.108308","article-title":"Electrochemical advanced oxidation for removal of xanthate from flotation process water","volume":"202","author":"Ozturk","year":"2023","journal-title":"Miner. Eng."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"534","DOI":"10.1016\/j.rser.2013.03.053","article-title":"Solar assisted photo degradation of wastewater by compound parabolic collectors: Review of design and operational parameters","volume":"24","author":"Tanveer","year":"2013","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Timmis, K.N. (2010). Psychrophiles\u2014Cold-Adapted Hydrocarbon-Degrading Microorganisms. Handbook of Hydrocarbon and Lipid Microbiology, Springer.","DOI":"10.1007\/978-3-540-77587-4"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1007\/s42250-025-01213-3","article-title":"Electrocoagulation-Assisted Fenton Reagent as Advanced Oxidation Processes used for Degradation of Organic Pollutants from Industrial Wastewater: A Review","volume":"8","author":"Fadhil","year":"2025","journal-title":"Chem. Afr."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"132493","DOI":"10.1016\/j.cej.2021.132493","article-title":"3D MXene hybrid architectures for the cold-resistant, rapid and selective capture of precious metals from electronic waste and mineral","volume":"428","author":"Qin","year":"2022","journal-title":"J. Chem. Eng."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2798","DOI":"10.1039\/D4SE00354C","article-title":"Status of fly ash-derived sustainable nanomaterials for batteries and supercapacitors","volume":"8","author":"Mushtaq","year":"2024","journal-title":"Sustain. Energy Fuels"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"138239","DOI":"10.1016\/j.electacta.2021.138239","article-title":"Electrochemical reactivity of S-phenacyl-O-ethyl-xanthates in hydroalcoholic (MeOH\/H2O 4:1) and anhydrous acetonitrile media","volume":"380","author":"Miranda","year":"2021","journal-title":"Electrochim. Acta"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Perotti, M., Iacoviello, F., Marian, N.M., Indelicato, C., Capitani, G., Salvini, R., Zampini, M., and Viti, C. (2023). Flotation Sludges from Precious Metal Recovery Processes: From Waste to Secondary Raw Material in Ceramics. Recycling, 8.","DOI":"10.3390\/recycling8020035"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"9233","DOI":"10.1021\/acs.chemrev.8b00252","article-title":"Design and Mechanisms of Asymmetric Supercapacitors","volume":"118","author":"Shao","year":"2018","journal-title":"Chem. Rev."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Gupta, S., Carrizosa, S.B., and Aberg, B. (2024). Designing high-performance asymmetric and hybrid energy devices via merging supercapacitive\/pseudopcapacitive and Li-ion battery type electrodes. Sci. Rep., 14.","DOI":"10.1038\/s41598-024-79622-6"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"100431","DOI":"10.1016\/j.cogsc.2020.100431","article-title":"Sustainable electroactive materials for energy storage","volume":"28","author":"Okhawilai","year":"2021","journal-title":"Curr. Opin. Green Sustain. Chem."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1326","DOI":"10.1126\/science.1216744","article-title":"Laser scribing of high-performance and flexible graphene-based electrochemical capacitors","volume":"335","author":"Strong","year":"2012","journal-title":"Science"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1434","DOI":"10.1149\/1.1838501","article-title":"Evidence for Direct \u03b3-NiOOH\u2194 \u03b2-Ni (OH)2 Transitions during Electrochemical Cycling of the Nickel Hydroxide Electrode","volume":"145","author":"Palacin","year":"1998","journal-title":"J. Electrochem. Soc."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"111368","DOI":"10.1016\/j.est.2024.111368","article-title":"Progressive updates on nickel hydroxide and its nanocomposite for electrochemical electrode material in asymmetric supercapacitor device","volume":"87","author":"Sharma","year":"2024","journal-title":"J. Energy Storage"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"155625","DOI":"10.1016\/j.apsusc.2022.155625","article-title":"Multi-dimensional Ni(OH)2\/(Ni(OH)2(NiOOH).167).857@Ni3S2 hierarchical structure for high-performance asymmetric supercapacitor","volume":"611","author":"Lu","year":"2023","journal-title":"Appl. Surf. Sci."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"593","DOI":"10.1016\/j.jpowsour.2015.12.059","article-title":"Design and construction of three-dimensional CuO\/polyaniline\/rGO ternary hierarchical architectures for high performance supercapacitors","volume":"306","author":"Zhu","year":"2016","journal-title":"J. Power Sources"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1745","DOI":"10.1021\/nn900297m","article-title":"Fabrication of graphene\/polyaniline composite paper via in situ anodic electropolymerization for high-performance flexible electrode","volume":"3","author":"Wang","year":"2009","journal-title":"ACS Nano"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"8467","DOI":"10.1021\/am4028235","article-title":"High-performance asymmetric supercapacitor based on nanoarchitectured polyaniline\/graphene\/carbon nanotube and activated graphene electrodes","volume":"17","author":"Shen","year":"2013","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"394","DOI":"10.1186\/s11671-017-2159-9","article-title":"Flexible Supercapacitors Based on Polyaniline Arrays Coated Graphene Aerogel Electrodes","volume":"12","author":"Yang","year":"2017","journal-title":"Nanoscale Res. Lett."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"266","DOI":"10.1016\/j.micromeso.2014.04.048","article-title":"RF xerogels with tailored porosity over the entire nanoscale","volume":"195","author":"Arenillas","year":"2014","journal-title":"Microporous Mesoporous Mater."},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Huang, C., Zhang, J., Young, N.P., Snaith, H.J., and Grant, P.S. (2016). Solid-State Supercapacitors with Rationally Designed Heterogeneous Electrodes Fabricated by Large Area Spray Processing for Wearable Energy Storage Applications. Sci. Rep., 6.","DOI":"10.1038\/srep25684"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"596","DOI":"10.1016\/j.jallcom.2017.03.157","article-title":"PAMPS\/MMT composite hydrogel electrolyte for solid-state supercapacitors","volume":"709","author":"Wang","year":"2017","journal-title":"J. Alloys Compd."},{"key":"ref_55","first-page":"4000","article-title":"Polyaniline nanofibers composite for high performance supercapacitor","volume":"10","author":"Atta","year":"2015","journal-title":"Int. J. Electrochem. Sci."},{"key":"ref_56","first-page":"202","article-title":"High performance asymmetric supercapacitors based on polyaniline\/reduced graphene oxide composite and activated carbon electrodes","volume":"320","author":"Zhang","year":"2016","journal-title":"J. Power Sources"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"A1317","DOI":"10.1149\/1.2197667","article-title":"Investigation of Pseudocapacitive Charge-Storage Reaction of MnO2 nH2O Supercapacitors in Aqueous Electrolytes","volume":"153","author":"Kuo","year":"2006","journal-title":"J. Electrochem. Soc."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"2699","DOI":"10.1149\/1.2050077","article-title":"Hydrous ruthenium oxide as an electrode material for electrochemical capacitors","volume":"142","author":"Zheng","year":"1995","journal-title":"J. Electrochem. Soc."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"8261","DOI":"10.1021\/cr400005f","article-title":"Recent advancement of nanostructured carbon for energy applications","volume":"113","author":"Yang","year":"2013","journal-title":"Chem. Rev."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"114665","DOI":"10.1016\/j.rser.2024.114665","article-title":"Unlocking the potential: Mining tailings as a source of sustainable nanomaterials","volume":"202","author":"Barraza","year":"2024","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"1800066","DOI":"10.1002\/gch2.201800066","article-title":"Effective Utilization of Waste Red Mud for High Performance Supercapacitor Electrodes","volume":"3","author":"Bhattacharya","year":"2018","journal-title":"Glob. Chall."},{"key":"ref_62","first-page":"100174","article-title":"Encouraging circular economy and sustainable environmental practices by addressing waste management and biomass energy production","volume":"5","author":"Islam","year":"2024","journal-title":"Reg. Sustain."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"5770","DOI":"10.1007\/s10904-024-03197-y","article-title":"Enhanced Photocatalytic and Antimicrobial Performance of Divalent Metal Substituted Nickel Nanostructures for Wastewater Treatment and Biological Applications","volume":"34","author":"Kumari","year":"2024","journal-title":"J. Inorg. Organomet. Polym. Mater."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1038\/s41545-022-00172-3","article-title":"A comprehensive review on the chemical regeneration of biochar adsorbent for sustainable wastewater treatment","volume":"5","author":"Alsawy","year":"2022","journal-title":"Npj Clean Water"},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"131503","DOI":"10.1016\/j.cej.2021.131503","article-title":"Recent advances in MOF-derived carbon-based nanomaterials for environmental applications in adsorption and catalytic degradation","volume":"427","author":"Liu","year":"2022","journal-title":"J. Chem. Eng."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"121058","DOI":"10.1016\/j.seppur.2022.121058","article-title":"Recent progress on electrocoagulation process for wastewater treatment: A review","volume":"292","author":"Das","year":"2022","journal-title":"Sep. Purif. Technol."},{"key":"ref_67","doi-asserted-by":"crossref","unstructured":"El Batouti, M., Alharby, N.F., and Elewa, M.M. (2022). Review of New Approaches for Fouling Mitigation in Membrane Separation Processes in Water Treatment Applications. Separations, 9.","DOI":"10.3390\/separations9010001"},{"key":"ref_68","doi-asserted-by":"crossref","unstructured":"Ayach, J., El Malti, W., Duma, L., Lalev\u00e9e, J., Al Ajami, M., Hamad, H., and Hijazi, A. (2024). Comparing Conventional and Advanced Approaches for Heavy Metal Removal in Wastewater Treatment: An In-Depth Review Emphasizing Filter-Based Strategies. Polymers, 16.","DOI":"10.3390\/polym16141959"},{"key":"ref_69","doi-asserted-by":"crossref","unstructured":"Li, X., Wang, B., Zhang, W., Zhang, X., and Wang, X. (2025). Adsorption of Aqueous Nickel Ion by Biomass Carboxymethyl Cellulose-Doped Boron Nitride Composites and Its Subsequent Energy Storage. Polymers, 17.","DOI":"10.3390\/polym17050567"},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"1902","DOI":"10.1002\/pat.4624","article-title":"An overview on the recent developments in polyaniline-based supercapacitors","volume":"30","author":"Banerjee","year":"2019","journal-title":"Polym. Adv. Technol."},{"key":"ref_71","first-page":"105","article-title":"Polymers and their Composites as Renewable and Flexible Materials for Boosting Energy Storage","volume":"1484","author":"Hameed","year":"2024","journal-title":"Materials for Boosting Energy Storage. Volume 2: Advances in Sustainable Energy Technologies"}],"container-title":["Gels"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2310-2861\/11\/6\/446\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:49:25Z","timestamp":1760032165000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2310-2861\/11\/6\/446"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,10]]},"references-count":71,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2025,6]]}},"alternative-id":["gels11060446"],"URL":"https:\/\/doi.org\/10.3390\/gels11060446","relation":{},"ISSN":["2310-2861"],"issn-type":[{"value":"2310-2861","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,10]]}}}