Environmental Nanotechnology, Monitoring and Management最新文献

{"title":"Reactive transport and sorption behavior of pollutants in presence of redox-sensitive nano Fe0 impregnated graphene: Advancing towards continuous water filtration","authors":"Jai Kishan Rajak ,&nbsp;Nitin Khandelwal ,&nbsp;Zahid Ahmad Ganie ,&nbsp;Dieter Schild ,&nbsp;Gopala Krishna Darbha","doi":"10.1016/j.enmm.2025.101053","DOIUrl":"10.1016/j.enmm.2025.101053","url":null,"abstract":"<div><div>Fe⁰ impregnated graphene has shown promising candidature for removing both organic and inorganic contaminants from aqueous solutions. The current study investigates and fills some of the missing gaps in their large-scale environmental applicability, including- contaminants removal from complex water matrices, simultaneous separation of multiple contaminants, and continuous water filtration possibilities. Both metals and dyes were chosen of varying ionic behavior to broaden the scope of the work.</div><div>One-step graphene oxide (GO) delamination and iron reduction were performed to prepare Fe⁰ impregnated graphene (GOI) composite. Results have shown growth of smaller spherical Fe⁰ nanoparticles (&lt; 50 nm) on graphene with good dispersion and preserved redox state. XPS analysis of reaction precipitate confirmed that GOI could reduce CrO₄^2- to less toxic Cr(III) through reductive sorption. Removal capacities in batch mode were Ni (30.5 mg/g) &lt; Cr (49.8 mg/g) &lt; Cd (93.7 mg/g) &lt; As (143.6 mg/g) in mono-metallic system. In a multi-metallic system, efficient total metal removal capacity (&gt;340 mg/g) and continuous filtration efficiency (85 mg/g) was observed. GOI composite has also shown efficient removal and continuous separation of cationic methylene blue (81.3 mg/g), anionic methyl orange (79.7 mg/g), and zwitterionic rhodamine-B (31.7 mg/g). Electrostatic attraction on heterogeneous GOI surface, redox transformation, complexation, and co-precipitation with generated iron-oxy-hydroxide were major contaminant removal mechanisms. Results conclude a good potential of GOI composite in the separation of multiple pollutants from environmental matrices and continuous filtration of contaminated waters.</div></div>","PeriodicalId":11716,"journal":{"name":"Environmental Nanotechnology, Monitoring and Management","volume":"23 ","pages":"Article 101053"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanoparticle based antigen detection of norovirus in human faecal samples: A proof-of-concept study","authors":"Rishi Pandey ,&nbsp;Pradip Gyawali ,&nbsp;Mark A.T. Blaskovich ,&nbsp;Sanjaya K.C.","doi":"10.1016/j.enmm.2025.101064","DOIUrl":"10.1016/j.enmm.2025.101064","url":null,"abstract":"<div><div>Immunocapture assays that are fast, affordable, and can be utilised as on-site sensors for detecting pathogens or their biomarkers hold great value for ensuring public health and food safety. As proof of concept, a magnetic immunocapture assay was developed to detect norovirus. Acommercially available monoclonal antibody capable of capturing both norovirus genogroup I and II (GI and GII) was conjugated to the magnetic nanoparticles (MNPs) for capture and sequestration of norovirus GI and GII under laboratory conditions. The capability of the functionalised MNPs to capture norovirus from the faecal extract was determined by reverse transcription-qPCR. The capture efficiency of MNPs was &gt;90 % for both genogroups of noroviruses. To complement the magnetic capture and enable rapid detection and genogroup identification, two different monoclonal antibodies specific to genogroups GI and GII were conjugated onto a fluorescent nanoparticle surface, and then used to quantify captured norovirus in a ‘sandwich’ assay. Replicate faecal extract suspensions containing 10³ gene copies of norovirus GI and GII per µL were tested with the magnetic capture-fluorescence detection assay platform, with quantification of fluorescent intensity. The fluorescent particle assay for the detection of the biomarkers matched the sensitivity of qPCR. This method doesn’t require any sample preparation steps like nucleic acid extraction and can be easily converted into a rapid point of need detection system. This dual nanoparticle system holds promise as an inexpensive and reliable analytical tool for classical qualitative immunoassays that are prone to false positives.</div></div>","PeriodicalId":11716,"journal":{"name":"Environmental Nanotechnology, Monitoring and Management","volume":"23 ","pages":"Article 101064"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Graphitic carbon nitride nanotubes decorated with ruthenium: New efficient visible-light-driven photocatalyst","authors":"Mohaddeseh Shahabi Nejad,&nbsp;Zahra Vakily,&nbsp;Ali Mostafavi,&nbsp;Hassan Sheibani","doi":"10.1016/j.enmm.2024.101034","DOIUrl":"10.1016/j.enmm.2024.101034","url":null,"abstract":"<div><div>The discharge of effluents containing antibiotics into the environment poses a significant challenge, contributing to the proliferation of resistant bacterial pathogens. Consequently, the removal and degradation of these contaminants from aqueous environments, particularly through photodegradation with potent photocatalysts, has attracted considerable research interest. In this research, A novel generation of visible-light photocatalyst was developed by immobilizing a ruthenium complex on modified graphitic carbon nitride nanotubes, with a focus on degrading the commonly used antibiotic, tetracycline. To achieve this, the synthesis of graphitic carbon nitride nanotubes (g-C₃N₄ NTs) was successfully conducted using the hydrothermal method, followed by functionalization with the 1,10-Phenantroline-5,6-dione ligand. Subsequently, the functionalized g-C₃N₄ NTs were further enhanced through the immobilization of dichloro(p-cymene)ruthenium(II) dimer. The structure and morphology of the prepared photocatalyst were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FT-IR)spectroscopy, and scanning and transmission electron microscopy (SEM &amp; TEM). Subsequently, the photocatalyst’s efficiency in optically degrading tetracycline antibiotics was evaluated in a suspension reactor equipped with a 60 W LED lamp. Key parameters such as catalyst dosage, irradiation duration, temperature, and pH were systematically optimized. The results indicated that the immobilization of the Ru complex onto functionalized g-C₃N₄ NTs significantly enhanced photocatalytic activity, resulting in a 43 % increase in degradation efficiency. Furthermore, Chemical Oxygen Demand (COD) analysis demonstrated that approximately 90 % mineralization of a 10 mg/L tetracycline solution could be achieved using 20 mg of Ru (II) complex/g-C₃N₄ NTs at pH 7 after 480 min, without the need for additional oxidants.</div></div>","PeriodicalId":11716,"journal":{"name":"Environmental Nanotechnology, Monitoring and Management","volume":"23 ","pages":"Article 101034"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143179316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wintertime water quality assessment via integrated indexical approaches with reference to drinking and irrigation standards in NW India","authors":"Saloni Kamboj,&nbsp;Nirankar Singh","doi":"10.1016/j.enmm.2024.101032","DOIUrl":"10.1016/j.enmm.2024.101032","url":null,"abstract":"<div><div>To assess the wintertime toxicity linked with the characteristics of public supply water, tap water samples were collected from the selected sites<!--> <!-->of Ambala district in India during October 2022 to February 2023 covering winter season.<!--> <!-->Following the standard procedures and protocols recommended by APHA, BIS and WHO, several<!--> <!-->characteristics were explored<!--> <!-->in order to find their linkages with the health issues of adults and children during winters. The irrigation water quality parameters were also taken into consideration during characterization. The high levels of toxic elements (Pb, As, Cd, and Ni) were observed at various sites during this period exceeding the BIS<!--> <!-->acceptable limits. The average<!--> <!-->levels of F^-, Cl^-, NO₃^–, SO₄^2-, PO₄^3- and HCO₃^– were found to be 0.261 mg L^-1, 27.95 mg L^-1, 0.234 mg L^-1, 47.99 mg L^-1, 0.210 mg L^-1 and 5.97 mg L^-1 respectively. Levels of As, Ni, Cd, Co, Cr, Cu, Pb, and Zn<!--> <!-->remained at 123.62 µgL^-1, 56.24 µgL^-1 2.59 µgL^-1, 1.367 µgL^-1, 9.45 µgL^-1, 8.79 µgL^-1, 77.92 µgL^-1, and 10.79 µgL^-1 <!-->respectively. The mean hazard indices were<!--> <!-->found greater than one (&gt;1) for<!--> <!-->children and adults both (0.96–5.5, 0.96–2.61)<!--> <!-->during this<!--> <!-->winter season. Owing to low body weight, children found more prone than adults to health issues. The mostly sites had good water quality indices (WQIs). Based on the SAR, RSC, MAR, SSP values, mostly samples were found<!--> <!-->in excellent category of water source for irrigation. Several statistical and geographic distributions were used to evaluate the samples<!--> <!-->for direct human consumption along with the associated health risk at the study area.<!--> <!-->This study, first time reports the toxicity levels associated with the tap water characteristics in the chosen area and discusses the novel findings of the hazard analysis with reference to direct intake of freshwater and water for irrigation.</div></div>","PeriodicalId":11716,"journal":{"name":"Environmental Nanotechnology, Monitoring and Management","volume":"23 ","pages":"Article 101032"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance by design of TiO2 nanostructured granules exploitable in water remediation applications","authors":"Maurizio Vespignani ,&nbsp;Ilaria Zanoni ,&nbsp;Simona Ortelli ,&nbsp;Magda Blosi ,&nbsp;Chiara Artusi ,&nbsp;Andreana Piancastelli ,&nbsp;Cesare Melandri ,&nbsp;Irini Furxhi ,&nbsp;Anna Luisa Costa","doi":"10.1016/j.enmm.2025.101071","DOIUrl":"10.1016/j.enmm.2025.101071","url":null,"abstract":"<div><div>The development of advanced materials through safe and sustainable methods has become a priority in the field of material science. This study addresses this need by exploring how different design options affect the performance of nano-TiO₂ granulated powders exploitable in water remediation applications. The high-shear wet granulation (HSWG) process parameters have been investigated to produce nanostructured powders that are easy to handle, disperse, and remove from liquids, while preserving their ability to adsorb and photodegrade water pollutants or encapsulate and stabilize active ingredients. We systematically examined a range of key variables, including liquid-to-solid ratio, granulation time, and impeller speed, which were identified as the primary factors affecting the size population. The percentage of the &gt; 1000 µm granules fraction reached 100 % by increasing the liquid-to-solid ratio up to 0.6 g_water/g_powder, while an increase in granulation time and impeller speed caused a reduction of the largest fraction by approximately 30 % and 20 %, respectively. Additionally, we investigated the addition of different binder agents, followed by calcination at 600 °C. We found a correlation between tapped density, open porosity, swelling ratio and compressive strength. Maltodextrin (MD) improved the degree of compaction resulting in the highest compressive strength (9.5 ± 0.2 MPa) and lowest release of titanium when redispersed in water, whilst micro acryl emulsion (MA) improved the sample porosity (80.6 ± 0.5 %) and its capacity to adsorb water (swelling ratio. The pro-oxidative potential of the granules was evaluated using an •OH radical sensitive probe. TiO₂-based granules showed a reactivity comparable to TiO₂ pristine nanopowders, consuming approximately 98 % of RNO after 4 h.</div></div>","PeriodicalId":11716,"journal":{"name":"Environmental Nanotechnology, Monitoring and Management","volume":"23 ","pages":"Article 101071"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simultaneous LC-MS/MS determination of multi-class emerging contaminants in an orange plant system","authors":"Mahdiyeh Otoukesh,&nbsp;Claudia Simarro-Gimeno,&nbsp;Félix Hernández,&nbsp;Elena Pitarch","doi":"10.1016/j.enmm.2025.101077","DOIUrl":"10.1016/j.enmm.2025.101077","url":null,"abstract":"<div><div>As freshwater supplies decline, agriculture is turning to alternative sources like recycled wastewater for irrigation. However, treated wastewater may still contain organic micropollutants (OMPs), which can contaminate soil, be absorbed by crops, and enter the food chain. This raises the need for analytical methods to reliable identify and quantify OMPs in vegetable and soil matrices at low concentrations. Additionally, advanced wastewater treatment methods are necessary to minimize OMPs in effluents from conventional wastewater treatment plants.</div><div>This study, part of a broader project on recycled wastewater for irrigating orange fields, focused on developing a modified QuEChERS method to determine 18 pesticides and 15 pharmaceuticals in soil, orange leaves and fruits. Compounds were quantified using liquid chromatography coupled to tandem mass spectrometry with a triple quadrupole. The methods were validated at two fortification levels (1–5 and 10–50 ng g⁻¹). Matrix effects were evaluated, showing a minimal impact in soil, but significant effects (&gt; 20 %) in oranges and leaves, requiring matrix-matched calibration and/or isotopically labeled internal standards for accurate correction. The recoveries for most compounds were within 70–120 %, with relative standard deviations under 20 %, and limits of quantification ranged 1–5 ng g⁻¹.</div><div>In real samples, the insecticide acetamiprid was the most bioaccumulated contaminant, exceeding 20 ng g⁻¹ in leaves. Eleven pesticides were detected at concentrations below the limit of quantification, and the pharmaceutical atorvastatin was found in a soil sample.</div></div>","PeriodicalId":11716,"journal":{"name":"Environmental Nanotechnology, Monitoring and Management","volume":"23 ","pages":"Article 101077"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monte Carlo simulation for human health risk assessment of groundwater contaminated with arsenic at an Iranian semi-arid region","authors":"Ali Mantashloo ,&nbsp;Reza Shokoohi ,&nbsp;Zahra Torkshavand ,&nbsp;Ebrahim Chavoshi ,&nbsp;Salman Khazaei ,&nbsp;Mohammad Khazaei ,&nbsp;Amir shabanloo","doi":"10.1016/j.enmm.2025.101069","DOIUrl":"10.1016/j.enmm.2025.101069","url":null,"abstract":"<div><div>The present study investigated the contamination of drinking water with arsenic and its human health risk assessment in Qorveh County, Kurdistan Province, Iran. The data of this study were collected and analyzed in the wet and dry seasons and from a total of 56 groundwater samples. This study used two deterministic and stochastic approaches to evaluate carcinogenic and non-carcinogenic risk. Monte Carlo simulation, which is based on the Markov chain approach, was used for risk assessment. The examination of heavy metals As, B, Cd, Cu, Hg, Mn, Ni, Pb, Sb, V, and Zn in the water samples reveals that except for the arsenic, the insignificant concentration of the abovementioned metals was found, consequently, the health risk studies were conducted focusing on the arsenic contamination. Data analysis revealed the average concentration of arsenic in the dry and wet seasons to be 14.93 ± 17.67 and 13.79 ± 16.57 μg/L, respectively. Furthermore, beyond 39 % and 35 % of the area of Qorveh County rely on groundwater sources having the arsenic contents more than the permissible level (10 µg/L) in dry and wet seasons, respectively. The Monte Carlo simulation output clearly showed that the HQ values ​​for the 95th percentile in the dry season were 3.58 and 2.03 for the age groups of children and adults, respectively. In other words, the non-carcinogenic risk for children is almost twice that of adults. All carcinogenic risk values was reported more than the acceptable threshold, typically set at 1 × 10⁻⁶ (or 1 in a million) by EPA. The sensitivity analysis of the contribution of arsenic concentration, duration of exposure, and rate of ingestion showed 89.5 %, 5.7 %, and 4.6 %, respectively, which indicates the major effect of arsenic concentration. The findings of this study provide an environmental alert to inform policy and attract appropriate financial resources for the management of drinking water sources containing arsenic in these areas.</div></div>","PeriodicalId":11716,"journal":{"name":"Environmental Nanotechnology, Monitoring and Management","volume":"23 ","pages":"Article 101069"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143829398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of fly ash/melamine composites for crystal violate dye removal from aqueous media","authors":"Imran Khan Rind ,&nbsp;Ahmet Sarı ,&nbsp;Mustafa Tuzen ,&nbsp;Muhammad Farooque Lanjwani ,&nbsp;Tawfik A. Saleh","doi":"10.1016/j.enmm.2025.101056","DOIUrl":"10.1016/j.enmm.2025.101056","url":null,"abstract":"<div><div>Fly ash (FA) as a low-cost and easily obtainable by-product from thermal power plants is considered for the decontamination of inorganic and organic pollutants from wastewater. In this work, FA was grafted with melamine and the obtained composite was used for the adsorption of crystal violet (CV) from water. By modification of melamine, the surface of FA was enhanced with amide groups as effective binding groups for CV molecules and therefore achieved higher sorption capacity. The chemical and textural characteristics of the FA/Melamine composite were studied by scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). Factorial designing was used for evaluating optimum adsorption parameters. ANOVA analysis of the P-value of individuals and combined variables was significant due to a P-value of less than 0.05 and a higher F-value. Equilibrium results show a monolayer isotherm model by Langmuir isotherm model with a maximum CV uptake capacity of 487 mg g⁻¹ under optimized conditions (250 mg adsorbent dosage, 10 ppm concentration, 30 min contact time and pH 6.0). Kinetic studies revealed that CV removal was nominated by the pseudo-second-order (PSO) model. CV dye molecules were adsorbed onto FA/Melamine composite via electrostatic attractions dipole–dipole interactions and n-π stacking interactions. Furthermore, the obtained results exposed that the synthesized FA/Melamine composite can be assessed as a promising sorbent for CV dye removal with high adsorption capacity.</div></div>","PeriodicalId":11716,"journal":{"name":"Environmental Nanotechnology, Monitoring and Management","volume":"23 ","pages":"Article 101056"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The hidden threat of microplastics in urban freshwater ecosystem: A comprehensive review","authors":"Md. Fahim Murshed,&nbsp;Nusrat Fardin Arpita,&nbsp;Amit Hasan Anik,&nbsp;Maisha Binte Sultan","doi":"10.1016/j.enmm.2025.101054","DOIUrl":"10.1016/j.enmm.2025.101054","url":null,"abstract":"<div><div>Microplastic (MP) pollution has become a pressing environmental issue, particularly in urban freshwater ecosystems, where it poses significant risks to water quality and public health. By integrating new data and insights, this article aims to deepen the understanding of MP contamination in urban freshwater ecosystems and its broader environmental implications. This article reviews the current literature of MPs focusing on urban freshwater ecosystems, often overlooked in favor of marine settings. It uniquely addresses the sources, pathways, and biomagnification of MPs in these environments, linking ecological effects to public health, and advocating for collaborative stakeholder action and innovative management strategies. This holistic approach provides a comprehensive view of MP pollution in urban contexts where aquatic organisms can ingest MPs present in these freshwater ecosystems and move through the food chain thus ultimately reaching the human body. The effects of MPs on the food chain are examined, particularly how they accumulate in organisms, transfer between different levels of the food chain, and increase in concentration as they move up through different trophic levels. To successfully tackle MP contamination, it pushes for collaborative action among stakeholders, including researchers, policymakers, and the community. It calls for enhanced research efforts to fill existing knowledge gaps and develop innovative management strategies to mitigate the impacts of MPs. Ultimately, this serves as a crucial resource for informing future policies and initiatives to preserve water quality and protect public health in the face of growing plastic pollution.</div></div>","PeriodicalId":11716,"journal":{"name":"Environmental Nanotechnology, Monitoring and Management","volume":"23 ","pages":"Article 101054"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancement of Congo red adsorption using oxidated nitrogen-doped carbon nanotubes","authors":"Alicia E. Chávez-Guajardo ,&nbsp;Luis Octavio Solis-Sanchez ,&nbsp;María Medina-Llamas ,&nbsp;Brenda I. Orea-Calderón ,&nbsp;Florentino López-Urías ,&nbsp;Emilio Muñoz-Sandoval ,&nbsp;Verónica L. Medina-Llamas","doi":"10.1016/j.enmm.2024.101037","DOIUrl":"10.1016/j.enmm.2024.101037","url":null,"abstract":"<div><div>This work reports the synthesis of nitrogen-doped multilayer carbon nanotubes (N-MWCNTs). The N-MWCNTs were subjected to mild oxidation in air at different temperatures and exposure times to obtain a variety of composites from N-MWCNTs with iron oxide nanoparticles up to mainly nanostructured hematite in its alpha phase (α-Fe₂O₃). X-ray diffraction allowed us to track the transformation path of the N-MWCNTs have a cross oxidation time. Each composite was fully characterized. FTIR analysis revealed that the oxidated N-MWCNTs exhibited a high content of carboxylic and carbonyl functional groups. Raman spectroscopy characterization shows a decrease in the D-band intensity and an increase in the 2D-band intensity as the oxidation temperature and oxidation time increase. For instance, the 5 min oxidized N-MWCNTs at 620 °C show a 3 % decrease in both the I_D/I_G and I_2D/I_G ratios. At 10 min at 620 °C, a 10 % decrease in the I_D/I_G ratio and a 15 % increase in the I_2D/I_G ratio were observed. The former results indicate the opening of the CNTs tips and the exposure of the graphitic layers as oxidation time increases. The TEM micrographs can easily corroborate the former trends. The performance of the pristine and oxidized N-MWCNTs was evaluated for the adsorption of Congo red (CR) as a model pollutant. The results indicate that mild oxidation temperatures (620 °C) and short oxidation times favor CR adsorption with a faster adsorption equilibrium than pristine N-MWCNTs. The percentage removal of pristine N-MWCNTS was 33 %. The oxidized samples at 620 °C had a higher adsorption removal of CR up to 36 % and 43 % when oxidation time was 5 and 10 min. The results demonstrate that oxidation thermal treatment reduces amorphous carbon and promotes the opening of the CNTs, increasing the active sites on the surface of the material, which facilitates interaction with CR.</div></div>","PeriodicalId":11716,"journal":{"name":"Environmental Nanotechnology, Monitoring and Management","volume":"23 ","pages":"Article 101037"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}