Applied Clay Science最新文献

{"title":"Topotactic route to novel layered titanosilicates via mild solution treatment of AM-4 at ambient temperature","authors":"Stanislav Ferdov ,&nbsp;Zhi Lin ,&nbsp;Rositsa Titiorenkova ,&nbsp;Nadia Petrova ,&nbsp;Boris Shivachev ,&nbsp;Rositsa Nikolova","doi":"10.1016/j.clay.2025.108027","DOIUrl":"10.1016/j.clay.2025.108027","url":null,"abstract":"<div><div>Layered hydrated titanosilicates capable of topotactic transformations are known in nature. However, their preparation in laboratory conditions is challenging. This work demonstrated the synthesis and characterization of two novel layered titanosilcates, MSA-1, Na₂[Ti₂Si₄O₁₂(OH)₂]∙1.6H₂O (<em>C</em>2<em>/c</em>, <em>a</em> = 27.6518(12), <em>b</em> = 8.68987(37), <em>c</em> = 5.26316(21) Å, <em>β</em> = 90.8916(33)^o, <em>V</em> = 1264.501(91) ų) and MSA-2, HTi₂Si₄O₁₁(OH)(OH)₂∙<em>n</em>H₂O (<em>n</em> is close to 1) (<em>C</em>2<em>/c</em>, <em>a</em> = 26.4573(21), <em>b</em> = 8.75932(72), <em>c</em> = 5.21790(39) Å, <em>β</em> = 92.2808(63)^o, <em>V</em> = 1208.28(17) ų), structurally similar to the minerals eliseevite and punkaruaivite, respectively. These materials were synthesized at room temperature by a 2D-2D transformation of AM-4 [Na₃(Na,H)Ti₂O₂[Si₂O₆]₂∙2H₂O] titanosilicate, a synthetic sodium counterpart of the mineral lintisite. The transformations involved a gradual lattice contraction due to the removal of Na⁺ cations from the interlayer space. This loss of positive charge was compensated by the protonation of underbonded framework oxygen atoms, resulting in the formation of hydroxyl groups (OH⁻). These OH groups were structurally integrated into the titanosilicate framework, which helped to preserve charge neutrality. Other transformations were also found by heating MSA-2 to 200 °C which led to a lattice contraction, decreased symmetry (<em>P</em>2₁<em>/c</em>, <em>a</em> = 11.9484(6), <em>b</em> = 8.7067(4), <em>c</em> = 5.2227(2) Å, <em>β</em> = 101.043(4)^o, <em>V</em> = 533.26(4) ų) and resulted in the formation of the layered titanosilicate L3 [Ti(Si₂O₅)(OH)(OH)]. Further heating of MSA-2 to 300 °C led to the formation of a phase similar to L3 but with a substantially smaller lattice (<em>P</em>2₁<em>/c</em>, <em>a</em> = 11.6257(8), <em>b</em> = 8.6809(5), <em>c</em> = 5.2235 Å, <em>β</em> = 100.906(4)^o, <em>V</em> = 517.65(5) ų). The MSA-2 showed high CO₂ adsorption capacity.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108027"},"PeriodicalIF":5.8,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145414422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hexadecyltrimethylammonium-modified bentonite for enhanced adsorption of per- and polyfluoroalkyl substances: Experiment and thermodynamic mechanism","authors":"Ze-Wei Ke ,&nbsp;Yu-Xin Liu ,&nbsp;Sheng-Jie Wei ,&nbsp;Peng Shen ,&nbsp;Kun Yang ,&nbsp;Yun-Min Chen ,&nbsp;Yu-Chao Li","doi":"10.1016/j.clay.2025.108022","DOIUrl":"10.1016/j.clay.2025.108022","url":null,"abstract":"<div><div><em>Per</em>- and polyfluoroalkyl substances (PFAS) pose significant environmental and human health concerns due to their extreme persistence and bioaccumulation potential, and widespread contamination. Conventional clay-based barriers, such as geosynthetic clay liners, exhibit limited PFAS containment capabilities owing to their inherently low adsorption capacity. To overcome this challenge, this paper synthesized hexadecyltrimethylammonium-modified bentonite (HDTMA-NaB) as a high-performance adsorbent for engineered containment applications. Comprehensive batch adsorption experiments demonstrated that HDTMA-NaB achieves substantially greater PFAS adsorption capacity compared to pristine bentonite, with adsorption kinetics following a pseudo-second-order model and isotherms were well-described by both Langmuir and Freundlich models. Molecular dynamics simulations unveiled a distinctive “head-attracted, tail-parallel” adsorption configuration, where PFAS molecules align with HDTMA surfactants within montmorillonite interlayers. Chain-length-dependent adsorption patterns were observed, with short-chain PFAS preferentially adsorbing at clay particle edges while long-chain PFAS penetrated deeper into interlayer spaces. Potential of mean force analysis quantitatively verified stronger adsorption affinity for long-chain PFAS, consistent with adsorption experiment observations, through deeper and more numerous energy minima. Thermodynamic analysis indicated that PFAS adsorption was driven by both enthalpic and entropic contributions, with entropy playing the dominant role. The entropic contribution primarily arose from hydrophobic interactions between PFAS fluorinated carbon chains and HDTMA alkyl chains, providing a mechanistic explanation for the observed chain-length-dependent adsorption behavior in adsorption experiments. Meanwhile, the enthalpic contribution arose from electrostatic attraction between PFAS anionic headgroups and HDTMA cationic trimethylammonium groups. These molecular-scale insights provide a fundamental basis for designing high-performance clay-based containment systems for PFAS mitigation.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108022"},"PeriodicalIF":5.8,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145414421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Construction of superhydrophobic CoZnAl-LDH coating on anodized aluminum surfaces to enhance corrosion and wear resistance","authors":"Guixiang Wang ,&nbsp;Qizi Wu ,&nbsp;Maomao Guo ,&nbsp;Shilong Zhang ,&nbsp;Qiuyan Luo ,&nbsp;Hao Yu ,&nbsp;Xuyan Guo ,&nbsp;Fuqiu Ma ,&nbsp;Haining Feng ,&nbsp;Ruizhi Wu ,&nbsp;Boris Krit","doi":"10.1016/j.clay.2025.108025","DOIUrl":"10.1016/j.clay.2025.108025","url":null,"abstract":"<div><div>In this study, a novel CoZnAl-LDH coating was synthesized in-situ on anodized aluminum through a hydrothermal method without introducing trivalent metal salts. Subsequently, a vanadate-intercalated LDH-VS coating was fabricated via ion exchange and hexadecyltrimethoxysilane (HDTMS) self-assembly, which integrated long-term corrosion resistance, friction reduction, and superhydrophobicity into a single coating. The morphology and structure of the coatings were investigated using SEM, EDS, XRD, FT-IR, and XPS. The coating performance was evaluated through scratch tests, contact angle, electrochemical, and friction wear tests. The results demonstrated that the contact angle of the LDH-VS increased from 26° to 154° and remained above 120° even after prolonged immersion, exhibiting outstanding self-cleaning and antifouling properties. After 28 days of immersion in 3.5 wt% NaCl solution, the corrosion current density of LDH-VS decreased by four orders of magnitude to 8.09 × 10⁻⁹ A·cm⁻² compared to bare aluminum alloy and the microstructure remained intact, indicating excellent long-term corrosion resistance. Friction tests confirmed the superior friction reduction of the modified coating, with the average friction coefficient of LDH-VS decreasing to 0.28, significantly lower than that of the aluminum alloy. Scratch tests also verified the coating's excellent adhesion strength. This study provides new insights into the development and application of LDH in superhydrophobicity, long-term corrosion protection, and wear resistance.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108025"},"PeriodicalIF":5.8,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145414419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Steam-assisted-crystallization synthesis of mesoporous hectorite: A universal adsorbent for rapid capture of methylene blue and copper ions","authors":"Derui Chen ,&nbsp;Chao Sun ,&nbsp;Keying Sun ,&nbsp;Mingyu Yan ,&nbsp;Shunyu Han ,&nbsp;Longbin Xu ,&nbsp;Xinyu Li ,&nbsp;Yongri Liang","doi":"10.1016/j.clay.2025.108026","DOIUrl":"10.1016/j.clay.2025.108026","url":null,"abstract":"<div><div>Eliminating organic dyes and heavy metal ions remains challenging in environmental remediation. Hectorite shows promise for this application due to its layered structure and negative surface charge, but conventional energy-intensive hydrothermal synthesis hinders scalable production. Herein, we develop a novel steam-assisted crystallization (SAC) strategy to synthesize mesoporous hectorite from leached natural clay. This one-step approach significantly reduces solvent use and energy requirements. According to the Langmuir model, the material exhibits exceptional adsorption capacities for methylene blue (MB, 603.3 mg·g⁻¹) and copper ions (Cu²⁺, 68.72 mg·g⁻¹), surpassing conventional adsorbents. Rapid equilibrium is achieved within 10 min (MB) and 5 min (Cu²⁺), facilitated by the abundance of active sites and mesoporous structure. MB adsorption involves electrostatic interactions, hydrogen bonding, and ion exchange, while Cu²⁺ uptake occurs primarily via complexation with secondary electrostatic contributions. This work enables the sustainable utilization of natural clay resources and the green, scalable production of high-performance mesoporous hectorite adsorbents.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108026"},"PeriodicalIF":5.8,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145414420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructural, physico-mechanical, optical and photocatalytic characteristics of kaolin-based eucryptite glass ceramics","authors":"Ahmed Yahya ,&nbsp;Sherif Allam ,&nbsp;Ola N. Almasarawi ,&nbsp;Salwa A.M. Abdel-Hameed ,&nbsp;Bastian Raab ,&nbsp;AbdelMonem Soltan ,&nbsp;Esmat M.A. Hamzawy","doi":"10.1016/j.clay.2025.108024","DOIUrl":"10.1016/j.clay.2025.108024","url":null,"abstract":"<div><div>Lithium aluminosilicates glass ceramics were prepared from quarried kaolin and artificial lithium carbonate. Different techniques were used to characterize the starting batches, glasses and glass ceramics, these are: laser PSDs, XRD, XRF, DSC, SEM-EDAX, bulk density, CTE, microhardness, FTIR, UV-Vis spectrophotometer in addition to Factsage (8.3) thermodynamic modeling software. Results show that the Al/Si ratio and total impurities of kaolin-based batches influence the crystallization of non-cracked and directly bounded coated eucryptite with shielding rims of lithium metasilicates, nepheline, leucite and silicate glassy phase. Notably, the low-grade kaolin-based batch motivates the crystallization of mature lithium aluminosilicate glass ceramics microstructure which enhances the bulk density (2.41 g/cm³), apparent porosity (0.7%), water absorption (0.29%), microhardness (394 kg/mm²), thermal expansion coefficient (₋0.76×10^-7°C^-1) at (25-500°C) and UV-V reflectance up to 86%. The mature microstructure with shielded rimmed eucryptite exhibits outstanding photocatalytic performance, achieving up to 92% removal of MB dye. Such lithium aluminosilicate glass ceramics could be promising in microelectronics and photocatalysis applications.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108024"},"PeriodicalIF":5.8,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Smectite functionalization for targeted zearalenone immobilization: Investigating the key role of surface chemistry and adsorption mechanisms","authors":"Jakub Matusik ,&nbsp;Klaudia Dziewiątka ,&nbsp;Youjun Deng","doi":"10.1016/j.clay.2025.108023","DOIUrl":"10.1016/j.clay.2025.108023","url":null,"abstract":"<div><div>This study investigated the efficiency of modified smectites for zearalenone (ZEN) removal, with a focus on the role of structural characteristics and surface chemistry. Cation exchange and/or calcination yielded poor performance (&lt;10% removal). In contrast, organic functionalization with amphiphilic molecules, significantly enhanced ZEN adsorption by interlayer expansion and increased hydrophobicity. Among the tested modifiers, hexadecyltrimethylammonium bromide (C16) exhibited the highest removal efficiency (∼85%; 0.1 ppm ZEN, 200 mg/L dosage), driven by high organic loading correlated with smectites' cation exchange capacity. The C16-modified smectites had hydrophobic domains containing neutral C16 molecules, which resulted in optimal structural conditions for ZEN uptake. The smectites modified with ethyl lauroyl arginate (LAE®) and cocamidopropyl betaine (CAPB) demonstrated lower ZEN removal (∼70% and ∼60%, respectively), limited by lower organic loading caused by functional groups of modifiers. Vitamin B1-functionalization showed high efficiency for Na-rich smectite (47.6±0.6%) due to efficient Na⁺ to B1 exchange and thus enhanced surface hydrophobization. All modified materials retained high performance under acidic conditions, while alkaline pH reduced efficiency, except for the C16-modified materials. Adsorption kinetics were rapid and independent of the temperature (18°C and 37°C), though the C16 materials showed slower uptake due to colloidal stability issues. Linear adsorption isotherms followed the Freundlich model, supporting a partitioning mechanism. The C16- and B1-modified smectites were resistant to competitive pepsin interactions in simulated gastric fluid, unlike the LAE® and CAPB. These findings emphasize the importance of appropriate functionalization of smectites for ZEN adsorption and support the development of adsorbents for mycotoxin mitigation in animal feed.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108023"},"PeriodicalIF":5.8,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hematite neocrystallisation derived from the experimental alteration of montmorillonite in NaCl solution","authors":"Ritwick Sudheer Kumar,&nbsp;Laurence N. Warr,&nbsp;Balu R. Thombare,&nbsp;Tobias Manzel,&nbsp;Georg H. Grathoff","doi":"10.1016/j.clay.2025.108008","DOIUrl":"10.1016/j.clay.2025.108008","url":null,"abstract":"<div><div>Smectite-rich bentonites are widely used as engineered barriers, and consequently, their stability and alteration behaviour have been extensively studied. Small hematite crystals frequently form during the alteration of bentonite under oxidising conditions; however, the mechanism of Fe₂O₃ formation remains poorly understood, especially its relationship to smectite alteration. This study presents mineralogical and geochemical analyses of hematite neocrystallisation from the experimental alteration of a purified montmorillonite fraction isolated from a Bavarian bentonite. Experiments were conducted in eight batch reactors containing monomineralic Na-saturated montmorillonite and a 0.1 M NaCl solution, at temperatures ranging from 160 to 220 °C and durations of 1–5 months, while other parameters were kept constant. Hematite crystallisation and smectite alteration mechanisms were investigated using transmission electron microscopy, X-ray diffraction and solution chemistry analyses. Results indicate that Fe ions released from partial dissolution (up to 7 wt%) of montmorillonite were mobilised and incorporated into neocrystallised hematite, producing log-normal crystal size distributions consistent with supply-controlled ripening mechanisms of crystal growth in a closed system. Time-dependent data indicate hematite growth is kinetically supply-controlled and self-limiting in low-Fe smectites, suggesting minimal long-term impact on engineered barrier performance. As iron oxides on clay minerals can mediate electron transfer in fluctuating redox environments, hematite formation may influence subsequent alteration processes, including microbial activity. Mass balance calculations suggest the formation of up to 6 % amorphous SiO₂, potentially limiting further reaction progress under these conditions.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108008"},"PeriodicalIF":5.8,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient Zn2+ transport and stable electrolyte/electrode interface achieved in acid-modified palygorskite-based quasi-solid-state electrolyte for high-performance zinc-ion batteries","authors":"Zhuo Zhang ,&nbsp;Jingyi Zeng ,&nbsp;Ming Liu ,&nbsp;Bing Xue","doi":"10.1016/j.clay.2025.108015","DOIUrl":"10.1016/j.clay.2025.108015","url":null,"abstract":"<div><div>The parasitic reactions induced by free water molecules in the electrolyte of aqueous zinc-ion batteries severely disrupt the stability of the electrolyte/electrode interface, significantly affecting the application performance of the batteries. To mitigate the adverse effects of free water molecules in the electrolyte of aqueous zinc-ion batteries, this paper utilized acid-treated palygorskite as the matrix and prepared a palygorskite-based quasi-solid-state electrolyte by adsorbing liquid electrolyte. This approach reduced the reactivity of water molecules in the electrolyte while enhancing the conductivity of zinc ions. The acid treatment with hydrochloric acid achieved fine-tuning of the palygorskite structure, increasing the number of surface -OH groups and enhancing the specific surface area of palygorskite to 199.16 m² g⁻¹. The plastic limit-liquid limit test results of the palygorskite-salt-water system showed that acid treatment improved the plastic limit (52.6 %) and liquid limit (68.4 %) of palygorskite, confirming that acid treatment could enhance the electrolyte adsorption capacity of palygorskite. Furthermore, acid treatment reduced the Zeta potential of palygorskite (−38.25 mV), strengthening the electrostatic attraction field of palygorskite in the palygorskite-salt-water system. This significantly improved the “relay-style” transmission efficiency of zinc ions in the palygorskite diffusion layer, promoting uniform deposition of zinc ions and inhibiting the growth of zinc dendrites. Simultaneously, it effectively suppressed the transmission of sulfate ions in this diffusion layer, thereby inhibiting the occurrence of side reactions and stabilizing the electrolyte/electrode interface. Based on the unique effect of acid treatment on the microstructure adjustment of palygorskite, the quasi-solid-state electrolyte prepared from acid-treated palygorskite exhibited an ionic conductivity of 20.84 mS cm⁻¹ and an ionic transference number of 0.87. The Zn//Zn symmetric cell assembled with this quasi-solid-state electrolyte demonstrated stable cycling for 3000 h at a current density of 0.2 mA cm⁻², with a polarization voltage less than 40 mV. The assembled Zn//MnO₂ full cell exhibited an initial discharge specific capacity of 240.57 mAh g⁻¹ at a current density of 0.33 A g⁻¹, and the average coulombic efficiency after 500 cycles was approximately 100 %.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108015"},"PeriodicalIF":5.8,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Steel-bentonite interaction at elevated temperatures","authors":"Šárka Šachlová ,&nbsp;Vlastislav Kašpar ,&nbsp;Michaela Matulová ,&nbsp;Petr Bezdička ,&nbsp;Zbyněk Veselka ,&nbsp;Petr Večerník","doi":"10.1016/j.clay.2025.108011","DOIUrl":"10.1016/j.clay.2025.108011","url":null,"abstract":"<div><div>The long-term durability of carbon steel, proposed as the outer layer of waste disposal packages in the Czech deep geological repository concept, is influenced by anaerobic conditions, elevated temperatures, irradiation, bentonite composition and water content. These factors were examined in a small-scale laboratory experiment within the European Joint Programme on Radioactive Waste Management, project CONtainer CORrosion under Disposal conditions (EURAD CONCORD). Carbon steel coupons were embedded in compacted (1600 kg⋅m^-3) bentonite of Ca/Mg-type (BCV) and reference bentonite of Na-type (MX-80), subjected to water saturation under a pressure of 5 MPa, heated to 90 °C and 150 °C, and irradiated with a ⁶⁰Co source at 0.4 Gy·h⁻¹ for 6 to 18 months.</div><div>Corrosion rates were primarily affected by temperature and saturation level. Similar rates were observed for both bentonites at 150 °C over 18 months, while lower rates were recorded for MX-80 at 90 °C and at ambient temperature. Irradiation had a negligible effect. Corrosion product composition strongly depended on temperature. At 90 °C, Fe-Ca‑carbonates formed in both bentonites, along with Fe-Ca(Mn-Mg)‑carbonates in BCV. At 150 °C, Fe-Si-O-rich layers and Fe-oxides developed, probably linked to the dissolution of amorphous silica and its incorporation into alteration products.</div><div>Elevated temperatures altered the mineralogy and chemistry of the bentonite. Changes included shifts in smectite basal spacing, enrichment with Fe^x+ and Mn²⁺, and modifications to exchangeable cation composition, including reduced Mg²⁺ content. Increased SO₄²⁻ and Cl⁻ concentrations in bentonite water leachates, particularly in BCV at 90 °C and MX-80 at 150 °C, partially correlated with higher corrosion rates. These results highlight the interconnected influence of temperature, bentonite type, and chemical interactions on carbon steel corrosion in repository-relevant environments.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108011"},"PeriodicalIF":5.8,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sepiolite-based hybrid photocatalyst via covalent immobilization of carbon quantum dots for visible-light water remediation","authors":"J.M. Sánchez-Silva ,&nbsp;J.L. Belmonte-Vázquez ,&nbsp;F. Carrasco-Marín ,&nbsp;R. Ocampo-Pérez ,&nbsp;E. Padilla-Ortega ,&nbsp;A. Aguilar-Aguilar","doi":"10.1016/j.clay.2025.108019","DOIUrl":"10.1016/j.clay.2025.108019","url":null,"abstract":"<div><div>Carbon quantum dots (CQDs) have emerged as promising nanomaterials due to their exceptional photophysical properties and environmental compatibility. However, their nanoscale size and colloidal nature often hinder their recovery and reuse in heterogeneous systems. In this study, were demonstrated the application of sepiolite as an efficient clay mineral support for the covalent immobilization of CQDs, leading to the formation of a stable hybrid material (Sep-NH₂-CQDs). The hybrid material was thoroughly characterized and confirmed the covalent bond of CQDs. Transmission electron microscopy (TEM) showed homogeneously distributed CQDs with an average size of 2.81 ± 0.8 nm. Fluorescence microscopy confirmed visible emission across a broad spectral range, while UV–vis diffuse reflectance spectroscopy (DRS) demonstrated improved light absorption between 400 and 700 nm. Photocatalytic tests showed that Sep-NH₂-CQDs achieved degradation efficiencies exceeding 90 % for methylene blue (MB), crystal violet (CV), and rhodamine B (RhB) under visible light in 90 min. The material also exhibited efficient performance in multicomponent dye mixtures, highlighting its potential for real wastewater treatment. Scavenger experiments indicated that the covalently grafting of CQDs promotes the generation of reactive oxygen species, which plays a critical role in the degradation mechanism. Overall, this work demonstrates the potential of modified sepiolite as a sustainable platform for CQD immobilization, offering a green and effective route for clay valorization and visible-light-driven water remediation applications.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"278 ","pages":"Article 108019"},"PeriodicalIF":5.8,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145359092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}