Search Results (323)

The influence of stress on gas sorption behavior and sorption-induced swelling in coal is critical for the success of CO₂-enhanced coalbed methane recovery (CO₂-ECBM) and geological carbon sequestration—a key strategy for mitigating climate change and promoting clean energy transitions. However, this influence remains insufficiently understood, largely due to experimental limitations (e.g., overreliance on powdered coal samples) and conflicting theoretical frameworks in existing studies. To address this gap, this study systematically investigates the effects of two distinct stress constraints—constant confining pressure and constant volume—on CO₂ adsorption capacity, adsorption kinetics, and associated swelling deformation of intact anthracite coal cores. An integrated experimental apparatus was custom-designed for this study, combining volumetric sorption measurement with high-resolution strain monitoring via the confining fluid displacement (CFD) method and the confining pressure response (CPR) method. This setup enables the quantification of CO₂–coal interactions under precisely controlled stress environments. Key findings reveal that stress conditions exert a regulatory role in shaping CO₂–coal behavior: constant confining pressure conditions enhance CO₂ adsorption capacity and sustain adsorption kinetics by accommodating matrix swelling, thereby preserving pore accessibility for continuous gas uptake. In contrast, constant volume constraints lead to rapid internal stress buildup, which inhibits further gas adsorption and accelerates the attainment of kinetic saturation. Sorption-induced swelling exhibits clear dependence on both pressure and constraint conditions. Elevated CO₂ pressure leads to increased strain, while constant confining pressure facilitates more gradual, sustained expansion. This is particularly evident at higher pressures, where adsorption-induced swelling prevails over mechanical constraints. These results help resolve key discrepancies in the existing literature by clarifying the dual role of stress in modulating both pore accessibility (for gas transport) and mechanical response (for matrix deformation). These insights provide essential guidance for optimizing CO₂ injection strategies and improving the long-term performance and sustainability of CO₂-ECBM and geological carbon storage projects, ultimately supporting global efforts in carbon emission reduction and sustainable energy resource utilization. Full article

Metal–organic frameworks (MOFs) are a class of highly ordered nanoporous crystals that possess a designable framework and unique chemical versatility. MOF thin films are ideal for nanotechnology-enabling applications, such as optoelectronics, catalytic coatings, and sensing. Mg-MOF-74 has been drawing increasing attention due to its remarkable CO₂ uptake capacity among MOFs and other commonly used CO₂ absorbents. Mg-MOF-74 thin films are currently fabricated by immersing selected substrates in precursor solutions, followed by a traditional solvothermal synthesis process. Herein, we introduce a rapid, easy, and cost-effective synthesis protocol to fabricate MOF thin films in an additive manner. In this work, the controllable synthesis of Mg-MOF-74 thin films directly on optical supports is reported for the first time. Dense, continuous, and uniform Mg-MOF-74 thin films are successfully fabricated on bare glass slides, with an average growth rate of up to 85.3 nm min⁻¹. The structural and optical properties of the resulting Mg-MOF-74 thin films are characterized using X-ray diffraction, atomic force microscopy, scanning electron microscopy, UV-Vis-NIR spectroscopy, and Fourier Transform Infrared Spectroscopy (FTIR). The CO₂ adsorption performance of the resulting Mg-MOF-74 thin films is studied using FTIR for the first time, which demonstrates that, as per the length of the light path for gas absorption, 1 nm Mg-MOF-74 thin film could provide 400.9 ± 18.0 nm absorption length for CO₂, which is achieved via the extraordinary CO₂ adsorption by Mg-MOF-74. The synthesis protocol enables the rapid synthesis of MOF thin films, highlighting Mg-MOF-74 in more CO₂-related applications, such as enhanced CO₂ adsorption and MOF-enhanced infrared gas sensing. Full article

This study reports on the synthesis, structural characterization and gas sorption studies of a homometallic 2D Cd²⁺ MOF and two heterometallic 3D Cd²⁺/Ca²⁺ and Cd²⁺/Sr²⁺ -MOFs based on the angular tetracarboxylic ligand 3,3′,4,4′-sulfonyltetracarboxylic acid (H₄STBA). The homometallic 2D Cd²⁺ MOF with the formula [NH₂(CH₃)₂]⁺₂[Cd(STBA)]²⁻_n·nDMF·1.5nH₂O—(1)_n·nDMF·1.5nH₂O was synthesized from the reaction of CdCl₂·H₂O and 3,3′,4,4′-diphthalic sulfonyl dianhydride (3,3′,4,4′-DPSDA) with stoichiometric ratio of 1:1.3 in DMF/H₂O (5/2 mL) at 100 °C. The two heterometallic Cd²⁺/Ca²⁺ and Cd²⁺/Sr²⁺ compounds were prepared from analogous reactions to this afforded (1)_n·nDMF·1.5nH₂O with the difference that the reaction mixture also contained AE(NO₃)₂ (AE²⁺ = Ca²⁺ or Sr²⁺) and, in particular, from the reaction of AE(NO₃)₂, CdCl₂·H₂O and 3,3′,4,4′-DPSDA with stoichiometric ratio 1:1.1:1.4 in DMF/H₂O (5/2 mL) at 100 °C. Notably, compounds [CdCa(STBA)(H₂O)₂]_n·0.5nDMF—(2)_n·0.5nDMF and [CdSr(STBA)(H₂O)₂]_n·0.5nDMF—(3)_n·0.5nDMF are the first heterometallic compounds Mⁿ⁺/AE²⁺ (M = any metal ion) reported containing ligand H₄STBA. The structure of (1)_n·nDMF·1.5nH₂O comprises a 2D network based on helical 1D chain secondary building unit (SBU) [Cd²⁺(STBA)⁴⁻)]²⁻. The 2D sheets are linked through hydrogen bonding interactions, giving rise to a pseudo-3D structure. On the other hand, compounds (2)_n·1.5nH₂O and (3)_n·1.5nH₂O display 3D microporous structures consisting of a helical 1D chain SBU [Cd²⁺AE²⁺(STBA)⁴⁻)]. All three compounds contain rhombic channels along c axes. The three MOFs exhibit an appreciable thermal stability, up to 350–400 °C. Gas sorption measurements on activated materials (2)_n and (3)_n revealed moderate BET surface areas of 370 m²/g and 343 m²/g, respectively, along with CO₂ uptake capacity of 2.58 mmol/g at 273 K. Full article

Forests play a crucial role in climate regulation through atmospheric CO₂ sequestration. However, disturbances like wildfires can severely compromise this function. This study assesses the ecological and economic consequences of a 2018 wildfire in The Roaches Nature Reserve, UK, focusing on post-fire carbon dynamics. A mixed woodland dominated by Pinus sylvestris L. and Larix decidua Mill. was evaluated via satellite imagery (remote sensing indices), dendrochronological analysis (wood cores sampling), and soil properties analyses. Remote sensing revealed areas of high fire severity and progressive vegetation decline. Tree-ring data indicated near-total mortality of L. decidua, while P. sylvestris showed greater post-fire resilience. Soil properties (e.g., soil organic carbon, biomass and microbial indices, etc.) assessed at a depth of 0–5 cm showed no significant changes. The analysis of CO₂ sequestration trends revealed a marked decline in burned areas, with post-fire sequestration reduced by approximately 70% in P. sylvestris and nearly 100% in L. decidua, in contrast to the stable patterns observed in the control stands during the same period. To estimate this important ecosystem service, we developed a novel CO₂ Sequestration Loss (CSL) index, which quantified the reduction in forest carbon uptake and underscored the impaired sequestration capacity of burned area. The decrease in CO₂ sequestration also resulted in a loss of regulating ecosystem service value, with burned areas showing a marked reduction compared to pre-fire conditions. Finally, a carbon loss of ~208 Mg ha⁻¹ was estimated in the burnt area compared to the control, mainly due to tree mortality rather than shallow soil carbon stock. Overall, our findings demonstrate that wildfire can substantially compromise the climate mitigation potential of temperate forests, highlighting the urgency of proactive management and restoration strategies. Full article

Lead (Pb) in soil poses serious environmental and health risks, and its removal requires complex and costly treatment methods to meet strict regulatory standards. To effectively address this challenge, innovative and efficient techniques are essential. Sepiolite-supported MnFe₂O₄ (MnFe₂O₄/SEP) composites were synthesized via a chemical co-precipitation method. The effects of MnFe₂O₄/SEP on soil pH, cation exchange capacity (CEC), available Pb content, Pb²⁺ uptake, and the activities of antioxidant enzymes in Brassica chinensis (Pak Choi) were examined. MnFe₂O₄/SEP showed superior Pb²⁺ adsorption compared to SEP alone, fitting Langmuir models, Dubinin-Radushkevich (D-R) models, Temkin models and pseudo-second-order kinetics. The maximum adsorption capacities at 298, 308, and 318 K were 459, 500 and 549 mg·g⁻¹, respectively. XPS analysis indicated that chemisorption achieved through ion exchange between Pb²⁺ and H⁺ was the main mechanism. MnFe₂O₄/SEP increased the soil pH by 0.2–1.5 units and CEC by 18–47%, while reducing available Pb by 12–83%. After treatment with MnFe₂O₄/SEP, acid-extractable and reducible Pb in the soil decreased by 14% and 39%, while oxidizable and residual Pb increased by 26% and 21%, respectively. In Brassica chinensis, MnFe₂O₄/SEP reduced Pb²⁺ uptake by 76%, increased chlorophyll content by 36%, and decreased malondialdehyde (MDA) levels by 36%. The activities of antioxidant enzymes—superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)—were decreased by 29%, 38% and 17%, respectively. These findings demonstrate that MnFe₂O₄/SEP is an efficient Pb²⁺ adsorbent that immobilizes Pb in soil mainly through ion exchange, thereby providing a highly effective strategy for remediating Pb-contaminated soils and improving plant health. Full article

Developing sustainable and high-performance sorbents for efficient CO₂ capture is essential for mitigating climate change and reducing industrial emissions. In this study, phosphorus-doped porous carbons (LPSP-T) were synthesized via a one-step activation–doping strategy using lotus petiole biomass as a precursor and sodium phytate as a dual-function activating and phosphorus-doping agent. The simultaneous activation and phosphorus incorporation at various temperatures (650–850 °C) under a nitrogen atmosphere produced carbons with tailored textural properties and surface functionalities. Among them, LPSP-700 exhibited the highest specific surface area (525 m²/g) and a hierarchical porous structure, with abundant narrow micropores (<1 nm) and phosphorus-containing surface groups that synergistically enhanced CO₂ capture performance. The introduction of P functionalities not only improved the surface polarity and binding affinity toward CO₂ but also promoted the formation of a well-connected pore network. As a result, LPSP-700 delivered a CO₂ uptake of 2.51 mmol/g at 25 °C and 1 bar (3.34 mmol/g at 0 °C), along with a high CO₂/N₂ selectivity, fast CO₂ adsorption kinetics and moderate isosteric heat of adsorption (Q_st). Furthermore, the dynamic CO₂ adsorption capacity (0.81 mmol/g) was validated by breakthrough experiments, and cyclic adsorption–desorption tests revealed excellent stability with negligible loss in performance over five cycles. Correlation analysis revealed pores < 2.02 nm as the dominant contributors to CO₂ uptake. Overall, this work highlights sodium phytate as an effective dual-role agent for simultaneous activation and phosphorus doping and validates LPSP-700 as a sustainable and high-performance sorbent for CO₂ capture under post-combustion conditions. Full article

Although laboratory testing to assess aerobic capacity has been a ‘gold standard’ in sports science, its high costs and time-consuming protocols may not be feasible for monitoring and tracking progress in limited conditions. In dancesport athletes, several field-based aerobic tests have been proposed, but the majority of them have been developed for ballet or contemporary dancers at the individual level, while the data among dance couples engaging in standard dance styles is lacking. Therefore, the main purpose of this study was to validate a newly developed Ballroom Aerobic Test (BAT) protocol against objective methods. Twelve standard dancesport couples (age: 20.4 ± 3.9 years; height: 172.1 ± 8.7 cm; weight: 60.1 ± 9.4 kg) with 8.2 ± 3.4 years of training and competing experience participated in this study. Ventilatory and metabolic parameters were generated using the MetaMax^® 3B portable gas analyzer (the BAT), while the KF1 (an increase in speed by 0.5 km * h⁻¹ by every minute) and Bruce protocols were followed in laboratory-based settings on the running ergometer. Large to very large correlations were obtained between the BAT and KF1/Bruce protocols for the absolute maximal oxygen uptake (VO₂max; r = 0.88 and 0.87) and relative VO₂max (r = 0.88 and 0.85), respiratory exchange ratio (RER; r = 0.78 and 0.76), expiratory ventilation (VE; r = 0.86 and 0.79), tidal volume (VT; r = 0.75; 95% CI = 0.57–0.87; p < 0.001), ventilatory equivalent for O₂ (VE/VO₂; r = 0.81 and 0.80) and CO₂ (VE/VCO₂; r = 0.78 and 0.82), and dead space (VD/VT; r = 0.70 and 0.74). The Bland–Altman plots indicated no systematic and proportional biases between the BAT and KF1 protocols (standard error of estimate; SEE = ± 3.36 mL * kg⁻¹ * min⁻¹) and the BAT and Bruce protocols (SEE = ± 3.75 mL * kg⁻¹ * min⁻¹). This study shows that the BAT exhibits satisfactory agreement properties against objective methods and is a valid dance protocol to accurately estimate aerobic capacity in dancesport athletes participating in standard dance styles. Full article

Background: Exercise duration at maximum oxygen uptake ($\dot{\mathrm{V}}$O₂max) appears to be influenced not only by metabolic factors but also by the interplay between brain dynamics and ventilatory regulation. This study examined how cortical activity, assessed via electroencephalography (EEG), relates to performance and acute fatigue regulation during a constant-load cycling test. We hypothesized that oscillatory activity in the theta, alpha, and beta bands would be associated with ventilatory coordination and endurance capacity. Methods: Thirty trained participants performed a cycling test to exhaustion at 90% maximal aerobic power. EEG and gas exchange were continuously recorded; ratings of perceived exertion were assessed immediately after exhaustion. Results: Beta power was negatively correlated with time spent at $\dot{\mathrm{V}}$O₂max (r = −0.542, p = 0.002). Theta and Alpha power alone showed no direct associations with endurance, but EEG–metabolic ratios revealed significant correlations. Specifically, the time to reach $\dot{\mathrm{V}}$O₂max correlated with Alpha/$\dot{\mathrm{V}}$O₂ (p < 0.001), Alpha/$\dot{\mathrm{V}}$CO₂ (p < 0.001), and Beta/$\dot{\mathrm{V}}$CO₂ (p = 0.002). The time spent at $\dot{\mathrm{V}}$O₂max correlated with Theta/$\dot{\mathrm{V}}$O₂ (p = 0.002) and Theta/$\dot{\mathrm{V}}$CO₂ (p < 0.001). The time-to-exhaustion was correlated with Theta/$\dot{\mathrm{V}}$CO₂ (p < 0.001) and Alpha/$\dot{\mathrm{V}}$CO₂ (p < 0.001). Conclusions: These findings indicate that cortical oscillations were associated with different aspects of acute fatigue regulation. Beta activity was associated with fatigue-related neural strain, whereas Theta and Alpha bands, when normalized to metabolic load, were consistent with a role in ventilatory coordination and motor control. EEG–metabolic ratios may provide exploratory indicators of brain–metabolism interplay during high-intensity exercise and could help guide future brain-body interactions in endurance performance. Full article

Rare earth elements (REEs) are critical for advanced technologies, with neodymium and praseodymium being essential to high-performance permanent magnets. The separation of these adjacent lanthanides represents a significant challenge due to their nearly identical chemical properties, with traditional chitosan surfaces exhibiting limited discrimination between chemically similar elements. Current separation methods require multiple processing steps and cannot maintain predetermined compositional ratios. Engineered polymer interfaces with controlled binding site distribution represents a critical advancement for selective separation, but achieving ratio-controlled extraction of adjacent elements remains challenging. Here, we demonstrate a novel interface engineering approach using alkali/urea dissolution to restructure chitosan networks, creating dual-template alkali/urea chitosan hydrogels (NdPr-AUCH) for simultaneous selective co-extraction of Nd(III) and Pr(III). We show that the dissolution–reformation process enables templated Nd:Pr selectivity ratios (1:1, 2:1, and 4:1) that directly correspond to synthesis compositions. NdPr-AUCH-11 achieved maximum uptake capacities of 19.85 mg/g for Nd(III) and 16.89 mg/g for Pr(III), while NdPr-AUCH-41 maintained 3.07:1 Nd:Pr selectivity in competitive environments. Thermodynamic analyses reveal consistently lower energy requirements for Nd(III) binding compared to Pr(III), demonstrating how interface engineering amplifies coordination differences between adjacent lanthanides. This work represents the first demonstration of ratio-controlled extraction of adjacent lanthanides within a single polymer matrix, advancing interface-engineered materials for selective rare earth recovery. Full article

This study reports the production of carbon adsorbents via microwave-assisted chemical activation of caraway seeds using potassium carbonate (K₂CO₃). Microwave irradiation enables rapid, energy-efficient heating, promoting effective pore development at relatively low activation temperatures (400–600 °C). The resulting carbons were comprehensively characterized in terms of surface area, pore structure, and surface chemistry, and their adsorption performance was evaluated for both cationic (methylene blue) and anionic (methyl red) dyes. The adsorbents exhibited specific surface areas ranging from 25 to 634 m²/g, with sorption capacities up to 217 mg/g for methylene blue and 171 mg/g for methyl red. Adsorption kinetics followed a pseudo-second-order model, and isotherm analysis revealed that Langmuir adsorption predominates for methylene blue, while Freundlich adsorption better describes methyl red uptake, reflecting surface heterogeneity. This work demonstrates that caraway seeds are a low-cost, sustainable precursor for producing microwave-activated carbons and provides new insights into the influence of activation temperature and surface chemistry on dye adsorption mechanisms, highlighting the practical potential of these materials for wastewater treatment applications. Full article

Fulvic acid’s potential to enhance plant growth has been recognized, but its effects on plant growth and nutrient uptake under nutrient stress remain unclear. This experiment investigated the effects of fulvic acid at concentrations of 0 mg L⁻¹ (T1), 30 mg L⁻¹ (T2), 60 mg L⁻¹ (T3), 90 mg L⁻¹ (T4), 120 mg L⁻¹ (T5), and 150 mg L⁻¹ (T6) on the growth performance of two rice varieties—Jikedao 654 (J 654) and Jiyang 100 (J 100)—under low-nitrogen stress in a hydroponic system. The effects of different fulvic acid application rates on the growth and photosynthetic characteristics, the key enzymes of nitrogen metabolism, antioxidant properties, and the osmotic adjustment substances of rice under low-nitrogen stress were evaluated. The results indicated that the addition of an appropriate concentration of fulvic acid could enhance the growth performance of J 654 and J 100 under low-nitrogen stress. Compared to T1 treatment, the total dry weight and nitrogen accumulation of rice showed greater increases in response to T3 and T4 treatments. The photosynthetic pigment content increased, photosynthesis was enhanced, and the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO₂ concentration (Ci), and transpiration rate (Tr) were improved. The activities of key enzymes in nitrogen metabolism, including nitrate reductase (NR), glutamine synthetase (GS), glutamate oxaloacetate transaminase (GOT), and glutamate pyruvate transaminase activity (GPT), were enhanced, thereby improving the capacity for nitrogen uptake and assimilation. The addition of fulvic acid also enhanced the antioxidant capacity, increased the superoxide dismutase (SOD), peroxide (POD) and catalase (CAT) activity and decreased the toxic effects of ROS, the production rate of O₂⁻, and the hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) content. The low-nitrogen stress was alleviated, thereby reducing the proline and soluble sugars content. Overall, it was demonstrated that adding an appropriate concentration (60–90 mg L⁻¹) of fulvic acid under low-nitrogen stress has a positive impact on the growth and development of rice. Our findings provide a theoretical basis for the application of fulvic acid in alleviating low-nitrogen stress in rice. Full article

Zeolitic imidazolate framework (ZIF)-8 materials exhibiting zinc metal centers partially replaced by cobalt or neodymium were successfully synthesized via a convenient coprecipitation method. The resulting materials were structurally and microstructurally characterized by SEM, XRD, FT-IR, and TGA, among other techniques. Subsequently, ZIF-8 nanoparticles were integrated into polyacrylonitrile fibers (PAN) via the electrospinning technique, followed by a secondary growth step to increase the ZIF-8 loading on the fiber’s surface. Furthermore, the characterization and evaluation of the materials’ CO₂ adsorption properties at low pressures revealed their volumetric CO₂ uptake capacities. The samples containing ZIF-8 powders modified with Co cations exhibited the best CO₂ capture performances of 26.48 and 8.08 cm³·g⁻¹ (at STP) for the unsupported and PAN-anchored materials, respectively. The strategy of seeding followed by secondary growth to anchor ZIF-8 onto PAN fibers is proposed as a novel and practical approach for adsorbent processing. Full article

Addressing the challenge of sulfonated lignite (SL) removal from oilfield wastewater, this study introduces a novel hierarchical MgFe-layered double hydroxide (LDH) adsorbent. The material was fabricated via in situ co-precipitation, utilizing a template formed by the NaCl-induced co-assembly of oleylaminopropyl betaine (OAPB) and sodium dodecyl sulfate (SLS) into zwitterionic, anionic, shear-responsive viscoelastic gels. This gel-templating approach yielded an LDH structure featuring a hierarchical pore network spanning 1–80 nm and a notably high specific surface area of 199.82 m²/g, as characterized by SEM and BET. The resulting MgFe-LDH demonstrated exceptional efficacy, achieving a SL removal efficiency exceeding 96% and a maximum adsorption capacity of 90.68 mg/g at neutral pH. Adsorption kinetics were best described by a pseudo-second-order model (R² > 0.99), with intra-particle diffusion identified as the rate-determining step. Equilibrium adsorption data conformed to the Langmuir isotherm, signifying monolayer uptake. Thermodynamic analysis confirmed the process was spontaneous (ΔG < 0) and exothermic (ΔH = −20.09 kJ/mol), driven primarily by electrostatic interactions and ion exchange. The adsorbent exhibited robust recyclability, maintaining over 79% of its initial capacity after three adsorption–desorption cycles. This gel-directed synthesis presents a sustainable pathway for developing high-performance adsorbents targeting complex contaminants in oilfield effluents. Full article

The use of supplementary cementitious materials and the CO₂ uptake capacity of cementitious materials—including recycled concrete aggregates—not only promotes the circular economy but may also present an opportunity to increase their ecoefficiency, thus improving the shrinkage and durability properties of concretes. This study analyses the impact of carbonated recycled aggregates and CO₂ curing on improving the properties of commercial structural self-compacting concrete. Recycled aggregate concretes (RACs) were produced using 50% and 60% coarse recycled concrete aggregate (RCA), in carbonated and uncarbonated forms, and two types of cement—ordinary Portland cement (CEM I) and CEM II/B-M Portland composite cement containing 24% less clinker than CEM I—all with similar compressive strengths. After evaluating the CO₂ curing process, the physical, mechanical, shrinkage, and durability properties (including suction and carbonation resistance) of the concretes were assessed. The properties of the RACs were compared with those achieved by conventional concrete, to generate insights for developing a highly sustainable concrete manufacturing process. Taking all the assessed properties into account, the CO₂ curing process improved concrete’s properties. In addition, RAC-C50-I concrete (using CEM I with carbonated RCA) and RAC50-II (using CEM IIB and uncarbonated RCA) exhibited the greatest durability, resulting in reductions in sorptivity values of 40% and 45%, and decreases in the carbonation coefficient of 16% and 21%, respectively, compared to concrete without CO₂ curing. Full article

This work evaluates the CO₂-adsorption relevance and cycling stability of graphene oxide–silica (GO-SiO₂) and reduced graphene oxide–silica (rGO-SiO₂) gels after amine functionalization, demonstrating high-capacity retention under repeated adsorption–desorption cycles: rGO-SiO₂-APTMS retains ≈96.3% of its initial uptake after 50 cycles, while GO-SiO₂-APTMS retains ≈90.0%. The use of surfactants to control the organization of inorganic and organic molecules has enabled the development of ordered mesostructures, such as mesoporous silica and organic/inorganic nanocomposites. Owing to the outstanding properties of graphene and its derivatives, synthesizing mesostructures intercalated between graphene sheets offers nanocomposites with novel morphologies and enhanced functionalities. In this study, GO-SiO₂ and rGO-SiO₂ gels were synthesized and characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TG), mass spectrometry (MS), N₂ adsorption–desorption isotherms, and transmission electron microscopy (TEM). The resulting materials exhibit a laminar architecture, with mesoporous silica domains grown between graphene-based layers; the silica contents are 83.6% and 87.6%, and the specific surface areas reach 446 and 710 m²·g⁻¹, respectively. The laminar architecture is retained regardless of the surfactant-removal route; however, in GO-SiO₂ obtained by solvent extraction, a fraction of the surfactant remains partially trapped. Together with their high surface area, hierarchical porosity, and amenability to surface functionalization, these features establish amine-grafted graphene–silica gels, particularly rGO-SiO₂-APTMS, as promising CO₂-capture adsorbents. Full article