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Search Results (974)

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Keywords = metal supported carbons

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17 pages, 5600 KiB  
Article
From Marshes to Mines: Germination and Establishment of Crinum bulbispermum on Gold Mine Tailings
by Vincent C. Clarke, Sarina Claassens, Dirk P. Cilliers and Stefan J. Siebert
Plants 2025, 14(15), 2443; https://doi.org/10.3390/plants14152443 (registering DOI) - 7 Aug 2025
Abstract
The growth potential of Crinum bulbispermum was evaluated on gold mine tailings. The primary objectives were to model the species’ climatic niche in relation to gold mining regions, assess its germination success on tailings, and compare seedling survival and growth on tailings versus [...] Read more.
The growth potential of Crinum bulbispermum was evaluated on gold mine tailings. The primary objectives were to model the species’ climatic niche in relation to gold mining regions, assess its germination success on tailings, and compare seedling survival and growth on tailings versus other soil types. Species distribution modelling identified the South African Grassland Biome on the Highveld (1000+ m above sea level), where the majority of gold mines are located, as highly suitable for the species. Pot trials demonstrated above 85% germination success across all soil treatments, including gold mine tailings, indicating its potential for restoration through direct seeding. An initial seedling establishment rate of 100% further demonstrated the species’ resilience to mine tailings, which are often seasonally dry, nutrient-poor, and may contain potentially toxic metals. However, while C. bulbispermum was able to germinate and establish in mine tailings, long-term growth potential (over 12 months) was constrained by low organic carbon content (0.11%) and high salinity (194.50 mS/m). These findings underscore the critical role of soil chemistry and organic matter in supporting long-term plant establishment and growth on gold tailings. Building on previous research, this study confirms the ability of this thick-rooted geophyte to tolerate chemically extreme soil conditions. Crinum bulbispermum shows promise for phytostabilization and as a potential medicinal plant crop on tailings. However, future research on microbial community interactions and soil amendment strategies is essential to ensure its long-term sustainability. Full article
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34 pages, 1294 KiB  
Perspective
Electromagnetic Radiation Shielding Using Carbon Nanotube and Nanoparticle Composites
by Bianca Crank, Brayden Fricker, Andrew Hubbard, Hussain Hitawala, Farhana Islam Muna, Olalekan Samuel Okunlola, Alexandra Doherty, Alex Hulteen, Logan Powers, Gabriel Purtell, Prakash Giri, Henry Spitz and Mark Schulz
Appl. Sci. 2025, 15(15), 8696; https://doi.org/10.3390/app15158696 (registering DOI) - 6 Aug 2025
Abstract
This paper showcases current developments in the use of carbon nanotube (CNT) and nanoparticle-based materials for electromagnetic radiation shielding. Electromagnetic radiation involves different types of radiation covering a wide spectrum of frequencies. Due to their good electrical conductivity, small diameter, and light weight, [...] Read more.
This paper showcases current developments in the use of carbon nanotube (CNT) and nanoparticle-based materials for electromagnetic radiation shielding. Electromagnetic radiation involves different types of radiation covering a wide spectrum of frequencies. Due to their good electrical conductivity, small diameter, and light weight, individual CNTs are good candidates for shielding radio and microwaves. CNTs can be organized into macroscale forms by dispersing them in polymers or by wrapping CNT strands into fabrics or yarn. Magnetic nanoparticles can also be incorporated into the CNT fabric to provide excellent shielding of electromagnetic waves. However, for shielding higher-frequency X-ray and gamma ray radiation, the situation is reversed. Carbon’s low atomic number means that CNTs alone are less effective than metals. Thus, different nanoparticles such as tungsten are added to the CNT materials to provide improved shielding of photons. The goal is to achieve a desired combination of light weight, flexibility, safety, and multifunctionality for use in shielding spacecraft, satellites, nuclear reactors, and medical garments and to support lunar colonization. Future research should investigate the effect of the size, shape, and configuration of nanoparticles on radiation shielding. Developing large-scale low-cost methods for the continuous manufacturing of lightweight multifunctional nanoparticle-based materials is also needed. Full article
(This article belongs to the Section Nanotechnology and Applied Nanosciences)
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27 pages, 3653 KiB  
Review
Design and Application of Atomically Dispersed Transition Metal–Carbon Cathodes for Triggering Cascade Oxygen Reduction in Wastewater Treatment
by Shengnan Huang, Guangshuo Lyu, Chuhui Zhang, Chunye Lin and Hefa Cheng
Molecules 2025, 30(15), 3258; https://doi.org/10.3390/molecules30153258 - 4 Aug 2025
Viewed by 140
Abstract
The precise synthesis of non-precious metal single-atom electrocatalysts is crucial for enhancing the yield of highly active reactive oxygen species (ROSs). Conventional oxidation methods, such as Fenton or NaClO processes, suffer from poor efficiency, high energy demand, and secondary pollution. In contrast, heterogeneous [...] Read more.
The precise synthesis of non-precious metal single-atom electrocatalysts is crucial for enhancing the yield of highly active reactive oxygen species (ROSs). Conventional oxidation methods, such as Fenton or NaClO processes, suffer from poor efficiency, high energy demand, and secondary pollution. In contrast, heterogeneous electro-Fenton systems based on cascade oxygen reduction reactions (ORRs), which require low operational voltage and cause pollutant degradation through both direct electron transfer and ROS generation, have emerged as a promising alternative. Recent studies showed that carbon cathodes decorated with atomically dispersed transition metals can effectively integrate the excellent conductivity of carbon supports with the tunable surface chemistry of metal centers. However, the electronic structure of active sites intrinsically hinders the simultaneous achievement of high activity and selectivity in cascade ORRs. This review summarizes the advances, specifically from 2020 to 2025, in understanding the mechanism of cascade ORRs and the synthesis of transition metal-based single-atom catalysts in cathode electrocatalysis for efficient wastewater treatment, and discusses the key factors affecting treatment performance. While employing atomically engineered cathodes is a promising approach for energy-efficient wastewater treatment, future efforts should overcome the barriers in active site control and long-term stability of the catalysts to fully exploit their potential in addressing water pollution challenges. Full article
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14 pages, 4979 KiB  
Article
Oxygen Vacancy-Engineered Ni:Co3O4/Attapulgite Photothermal Catalyst from Recycled Spent Lithium-Ion Batteries for Efficient CO2 Reduction
by Jian Shi, Yao Xiao, Menghan Yu and Xiazhang Li
Catalysts 2025, 15(8), 732; https://doi.org/10.3390/catal15080732 - 1 Aug 2025
Viewed by 276
Abstract
Accelerated industrialization and surging energy demands have led to continuously rising atmospheric CO2 concentrations. Developing sustainable methods to reduce atmospheric CO2 levels is crucial for achieving carbon neutrality. Concurrently, the rapid development of new energy vehicles has driven a significant increase [...] Read more.
Accelerated industrialization and surging energy demands have led to continuously rising atmospheric CO2 concentrations. Developing sustainable methods to reduce atmospheric CO2 levels is crucial for achieving carbon neutrality. Concurrently, the rapid development of new energy vehicles has driven a significant increase in demand for lithium-ion batteries (LIBs), which are now approaching an end-of-life peak. Efficient recycling of valuable metals from spent LIBs represents a critical challenge. This study employs conventional hydrometallurgical processing to recover valuable metals from spent LIBs. Subsequently, Ni-doped Co3O4 (Ni:Co3O4) supported on the natural mineral attapulgite (ATP) was synthesized via a sol–gel method. The incorporation of a small amount of Ni into the Co3O4 lattice generates oxygen vacancies, inducing a localized surface plasmon resonance (LSPR) effect, which significantly enhances charge carrier transport and separation efficiency. During the photocatalytic reduction of CO2, the primary product CO generated by the Ni:Co3O4/ATP composite achieved a high production rate of 30.1 μmol·g−1·h−1. Furthermore, the composite maintains robust catalytic activity even after five consecutive reaction cycles. Full article
(This article belongs to the Special Issue Heterogeneous Catalysis in Air Pollution Control)
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29 pages, 4159 KiB  
Review
Nanomaterials for Smart and Sustainable Food Packaging: Nano-Sensing Mechanisms, and Regulatory Perspectives
by Arjun Muthu, Duyen H. H. Nguyen, Chaima Neji, Gréta Törős, Aya Ferroudj, Reina Atieh, József Prokisch, Hassan El-Ramady and Áron Béni
Foods 2025, 14(15), 2657; https://doi.org/10.3390/foods14152657 - 29 Jul 2025
Viewed by 494
Abstract
The global food industry is facing growing pressure to enhance food safety, extend shelf life, minimize waste, and adopt environmentally sustainable packaging solution. Nanotechnology offers innovative ways to meet these demands by enabling the creation of smart and sustainable food packaging systems. Due [...] Read more.
The global food industry is facing growing pressure to enhance food safety, extend shelf life, minimize waste, and adopt environmentally sustainable packaging solution. Nanotechnology offers innovative ways to meet these demands by enabling the creation of smart and sustainable food packaging systems. Due to their unique properties, nanomaterials can significantly enhance the functional performance of packaging by boosting mechanical strength, barrier efficiency, antimicrobial activity, and responsiveness to environmental stimuli. This review provides a comprehensive overview of nanomaterials used as smart and sustainable food packaging, focusing on their role in active and intelligent packaging systems. By integrating nanomaterials like metal and metal oxide nanoparticles, carbon-based nanostructures, and nano-biopolymers, packaging can now perform real-time sensing, spoilage detection, and traceability. These systems improve food quality management and supply chain transparency while supporting global sustainability goals. The review also discusses potential risks related to nanomaterials’ migration, environmental impact, and consumer safety, as well as the current regulatory landscape and limitations in industrial scalability. Emphasis is placed on the importance of standardized safety assessments and eco-friendly design to support responsible innovation. Overall, nano-enabled smart packaging represents a promising strategy for advancing food safety and sustainability. Future developments will require collaboration across disciplines and robust regulatory frameworks to ensure the safe and practical application of nanotechnology in food systems. Full article
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36 pages, 3579 KiB  
Article
RNA Sequencing Reveals Inflammatory and Metabolic Changes in the Lung and Brain After Carbon Black and Naphthalene Whole Body Inhalation Exposure in a Rodent Model of Military Burn Pit Exposures
by Allison M. Haaning, Brian J. Sandri, Henry L. Wyneken, William T. Goldsmith, Joshua P. Nixon, Timothy R. Nurkiewicz, Chris H. Wendt, Paul Barach, Janeen H. Trembley and Tammy A. Butterick
Int. J. Mol. Sci. 2025, 26(15), 7238; https://doi.org/10.3390/ijms26157238 - 26 Jul 2025
Viewed by 562
Abstract
Military personnel deployed to Iraq and Afghanistan were exposed to emissions from open-air burn pits, where plastics, metals, and medical waste were incinerated. These exposures have been linked to deployment-related respiratory diseases (DRRD) and may also impact neurological health via the lung–brain axis. [...] Read more.
Military personnel deployed to Iraq and Afghanistan were exposed to emissions from open-air burn pits, where plastics, metals, and medical waste were incinerated. These exposures have been linked to deployment-related respiratory diseases (DRRD) and may also impact neurological health via the lung–brain axis. To investigate molecular mechanisms, adult male rats were exposed to filtered air, naphthalene (a representative volatile organic compound), or a combination of naphthalene and carbon black (surrogate for particulate matter; CBN) via whole-body inhalation (six hours/day, three consecutive days). Lung, brain, and plasma samples were collected 24 h after the final exposure. Pro-inflammatory biomarkers were assessed using multiplex electrochemiluminescence and western blot. Differentially expressed genes (DEGs) were identified by RNA sequencing, and elastic net modeling was used to define exposure-predictive gene signatures. CBN exposure altered inflammatory biomarkers across tissues, with activation of nuclear factor kappa B (NF-κB) signaling. In the lung, gene set enrichment revealed activated pathways related to proliferation and inflammation, while epithelial–mesenchymal transition (EMT) and oxidative phosphorylation were suppressed. In the brain, EMT, inflammation, and senescence pathways were activated, while ribosomal function and oxidative metabolism were downregulated. Elastic net modeling identified a lung gene signature predictive of CBN exposure, including Kcnq3, Tgfbr1, and Tm4sf19. These findings demonstrate that inhalation of a surrogate burn pit mixture induces inflammatory and metabolic gene expression changes in both lung and brain tissues, supporting the utility of this animal model for understanding systemic effects of airborne military toxicants and for identifying potential biomarkers relevant to DRRD and Veteran health. Full article
(This article belongs to the Section Molecular Pathology, Diagnostics, and Therapeutics)
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25 pages, 3454 KiB  
Article
Dynamic Temperature–Vacuum Swing Adsorption for Sustainable Direct Air Capture: Parametric Optimisation for High-Purity CO2 Removal
by Maryam Nasiri Ghiri, Hamid Reza Nasriani, Leila Khajenoori, Samira Mohammadkhani and Karl S. Williams
Sustainability 2025, 17(15), 6796; https://doi.org/10.3390/su17156796 - 25 Jul 2025
Viewed by 571
Abstract
Direct air capture (DAC), as a complementary strategy to carbon capture and storage (CCS), offers a scalable and sustainable pathway to remove CO2 directly from the ambient air. This study presents a detailed evaluation of the amine-functionalised metal-organic framework (MOF) sorbent, mmen-Mg [...] Read more.
Direct air capture (DAC), as a complementary strategy to carbon capture and storage (CCS), offers a scalable and sustainable pathway to remove CO2 directly from the ambient air. This study presents a detailed evaluation of the amine-functionalised metal-organic framework (MOF) sorbent, mmen-Mg2(dobpdc), for DAC using a temperature–vacuum swing adsorption (TVSA) process. While this sorbent has demonstrated promising performance in point-source CO2 capture, this is the first dynamic simulation-based study to rigorously assess its effectiveness for low-concentration atmospheric CO2 removal. A transient one-dimensional TVSA model was developed in Aspen Adsorption and validated against experimental breakthrough data to ensure accuracy in capturing both the sharp and gradual adsorption kinetics. To enhance process efficiency and sustainability, this work provides a comprehensive parametric analysis of key operational factors, including air flow rate, temperature, adsorption/desorption durations, vacuum pressure, and heat exchanger temperature, on process performance, including CO2 purity, recovery, productivity, and specific energy consumption. Under optimal conditions for this sorbent (vacuum pressure lower than 0.15 bar and feed temperature below 15 °C), the TVSA process achieved ~98% CO2 purity, recovery over 70%, and specific energy consumption of about 3.5 MJ/KgCO2. These findings demonstrate that mmen-Mg2(dobpdc) can achieve performance comparable to benchmark DAC sorbents in terms of CO2 purity and recovery, underscoring its potential for scalable DAC applications. This work advances the development of energy-efficient carbon removal technologies and highlights the value of step-shape isotherm adsorbents in supporting global carbon-neutrality goals. Full article
(This article belongs to the Section Waste and Recycling)
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16 pages, 1188 KiB  
Article
Preparation and Performance Evaluation of Modified Amino-Silicone Supercritical CO2 Viscosity Enhancer for Shale Oil and Gas Reservoir Development
by Rongguo Yang, Lei Tang, Xuecheng Zheng, Yuanqian Zhu, Chuanjiang Zheng, Guoyu Liu and Nanjun Lai
Processes 2025, 13(8), 2337; https://doi.org/10.3390/pr13082337 - 23 Jul 2025
Viewed by 344
Abstract
Against the backdrop of global energy transition and strict environmental regulations, supercritical carbon dioxide (scCO2) fracturing and oil displacement technologies have emerged as pivotal green approaches in shale gas exploitation, offering the dual advantages of zero water consumption and carbon sequestration. [...] Read more.
Against the backdrop of global energy transition and strict environmental regulations, supercritical carbon dioxide (scCO2) fracturing and oil displacement technologies have emerged as pivotal green approaches in shale gas exploitation, offering the dual advantages of zero water consumption and carbon sequestration. However, the inherent low viscosity of scCO2 severely restricts its sand-carrying capacity, fracture propagation efficiency, and oil recovery rate, necessitating the urgent development of high-performance thickeners. The current research on scCO2 thickeners faces a critical trade-off: traditional fluorinated polymers exhibit excellent philicity CO2, but suffer from high costs and environmental hazards, while non-fluorinated systems often struggle to balance solubility and thickening performance. The development of new thickeners primarily involves two directions. On one hand, efforts focus on modifying non-fluorinated polymers, driven by environmental protection needs—traditional fluorinated thickeners may cause environmental pollution, and improving non-fluorinated polymers can maintain good thickening performance while reducing environmental impacts. On the other hand, there is a commitment to developing non-noble metal-catalyzed siloxane modification and synthesis processes, aiming to enhance the technical and economic feasibility of scCO2 thickeners. Compared with noble metal catalysts like platinum, non-noble metal catalysts can reduce production costs, making the synthesis process more economically viable for large-scale industrial applications. These studies are crucial for promoting the practical application of scCO2 technology in unconventional oil and gas development, including improving fracturing efficiency and oil displacement efficiency, and providing new technical support for the sustainable development of the energy industry. This study innovatively designed an amphiphilic modified amino silicone oil polymer (MA-co-MPEGA-AS) by combining maleic anhydride (MA), methoxy polyethylene glycol acrylate (MPEGA), and amino silicone oil (AS) through a molecular bridge strategy. The synthesis process involved three key steps: radical polymerization of MA and MPEGA, amidation with AS, and in situ network formation. Fourier transform infrared spectroscopy (FT-IR) confirmed the successful introduction of ether-based CO2-philic groups. Rheological tests conducted under scCO2 conditions demonstrated a 114-fold increase in viscosity for MA-co-MPEGA-AS. Mechanistic studies revealed that the ether oxygen atoms (Lewis base) in MPEGA formed dipole–quadrupole interactions with CO2 (Lewis acid), enhancing solubility by 47%. Simultaneously, the self-assembly of siloxane chains into a three-dimensional network suppressed interlayer sliding in scCO2 and maintained over 90% viscosity retention at 80 °C. This fluorine-free design eliminates the need for platinum-based catalysts and reduces production costs compared to fluorinated polymers. The hierarchical interactions (coordination bonds and hydrogen bonds) within the system provide a novel synthetic paradigm for scCO2 thickeners. This research lays the foundation for green CO2-based energy extraction technologies. Full article
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26 pages, 4285 KiB  
Article
Machinability and Geometric Evaluation of FFF-Printed PLA-Carbon Fiber Composites in CNC Turning Operations
by Sergio Martín-Béjar, Fermín Bañón-García, Carolina Bermudo Gamboa and Lorenzo Sevilla Hurtado
Appl. Sci. 2025, 15(15), 8141; https://doi.org/10.3390/app15158141 - 22 Jul 2025
Viewed by 218
Abstract
Fused Filament Fabrication (FFF) enables the manufacturing of complex polymer components. However, surface finish and dimensional accuracy remain key limitations for their integration into functional assemblies. This study explores the potential of conventional turning as a post-processing strategy to improve the geometric and [...] Read more.
Fused Filament Fabrication (FFF) enables the manufacturing of complex polymer components. However, surface finish and dimensional accuracy remain key limitations for their integration into functional assemblies. This study explores the potential of conventional turning as a post-processing strategy to improve the geometric and surface quality of PLA reinforced with carbon fiber (CF) parts produced by FFF. Machinability was evaluated through the analysis of cutting forces, thermal behavior, energy consumption, and surface integrity under varying cutting speeds, feed rates, and specimen slenderness. The results indicate that feed is the most influential parameter across all performance metrics, with lower values leading to improved dimensional accuracy and surface finish, achieving the most significant reductions of 63% in surface roughness (Sa) and 62% in cylindricity deviation. Nevertheless, the surface roughness is higher than that of metals, and deviations in geometry along the length of the specimen have been observed. A critical shear stress of 0.237 MPa has been identified as the limit for interlayer failure, defining the boundary conditions for viable cutting operation. The incorporation of CNC turning as a post-processing step reduced the total fabrication time by approximately 83% compared with high-resolution FFF, while maintaining dimensional accuracy and enhancing surface quality. These findings support the use of machining operations as a viable and efficient post-processing method for improving the functionality of polymer-based components produced by additive manufacturing. Full article
(This article belongs to the Special Issue Advances in Carbon Fiber Reinforced Polymers (CFRPs))
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14 pages, 3849 KiB  
Article
Alkaline Earth Carbonate Engineered Pt Electronic States for High-Efficiency Propylene Oxidation at Low Temperatures
by Xuequan Sun, Yishu Lv, Yuan Shu, Yanglong Guo and Pengfei Zhang
Catalysts 2025, 15(8), 696; https://doi.org/10.3390/catal15080696 - 22 Jul 2025
Viewed by 380
Abstract
Alkaline earth elements have emerged as crucial electronic modifiers for regulating active sites in catalytic systems, yet the influence of metal–support interactions (MSIs) between alkaline earth compounds and active metals remains insufficiently understood. This study systematically investigated Pt nanoparticles supported on alkaline earth [...] Read more.
Alkaline earth elements have emerged as crucial electronic modifiers for regulating active sites in catalytic systems, yet the influence of metal–support interactions (MSIs) between alkaline earth compounds and active metals remains insufficiently understood. This study systematically investigated Pt nanoparticles supported on alkaline earth carbonates (Pt/MCO3, M = Mg, Ca, Ba) for low-temperature propylene combustion. The Pt/BaCO3 catalyst exhibited outstanding performance, achieving complete propylene conversion at 192 °C, significantly lower than Pt/MgCO3 (247 °C) and Pt/CaCO3 (282 °C). The enhanced activity stemmed from distinct MSI effects among the supports, with Pt/BaCO3 showing the poorest electron enrichment and lowest propylene adsorption energy. Through kinetic analyses, 18O2 isotope labeling, and comprehensive characterization, the reaction was confirmed to follow the Mars–van Krevelen (MvK) mechanism. Pt/BaCO3 achieves an optimal balance between propylene and oxygen adsorption, a critical factor underlying its superior activity. Full article
(This article belongs to the Section Catalytic Materials)
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15 pages, 2806 KiB  
Article
Ni-MOF/g-C3N4 S-Scheme Heterojunction for Efficient Photocatalytic CO2 Reduction
by Muhammad Sabir, Mahmoud Sayed, Iram Riaz, Guogen Qiu, Muhammad Tahir, Khuloud A. Alibrahim and Wang Wang
Materials 2025, 18(14), 3419; https://doi.org/10.3390/ma18143419 - 21 Jul 2025
Viewed by 498
Abstract
The rapid recombination of photoinduced charge carriers in semiconductors remains a significant challenge for their practical application in photocatalysis. This study presents the design of a step-scheme (S-scheme) heterojunction composed of carbon nitride (g-C3N4) and nickel-based metal–organic framework (Ni-MOF) [...] Read more.
The rapid recombination of photoinduced charge carriers in semiconductors remains a significant challenge for their practical application in photocatalysis. This study presents the design of a step-scheme (S-scheme) heterojunction composed of carbon nitride (g-C3N4) and nickel-based metal–organic framework (Ni-MOF) to achieve enhanced charge separation. The establishment of an S-scheme charge transfer configuration at the interface of the Ni-MOF/g-C3N4 heterostructure plays a pivotal role in enabling efficient charge carrier separation, and hence, high CO2 photoreduction efficiency with a CO evolution rate of 1014.6 µmol g−1 h−1 and selectivity of 95% under simulated solar illumination. CO evolution represents an approximately 3.7-fold enhancement compared to pristine Ni-MOF. Density functional theory (DFT) calculations, supported by in situ irradiated X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) experimental results, confirmed the establishment of a well-defined and strongly bonded interface, which improves the charge transfer and separation following the S-scheme mechanism. This study sheds light on MOF-based S-scheme heterojunctions as fruitful and selective alternatives for practical CO2 photoreduction. Full article
(This article belongs to the Section Energy Materials)
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40 pages, 1777 KiB  
Review
Nanomaterials for Direct Air Capture of CO2: Current State of the Art, Challenges and Future Perspectives
by Cataldo Simari
Molecules 2025, 30(14), 3048; https://doi.org/10.3390/molecules30143048 - 21 Jul 2025
Viewed by 439
Abstract
Direct Air Capture (DAC) is emerging as a critical climate change mitigation strategy, offering a pathway to actively remove atmospheric CO2. This comprehensive review synthesizes advancements in DAC technologies, with a particular emphasis on the pivotal role of nanostructured solid sorbent [...] Read more.
Direct Air Capture (DAC) is emerging as a critical climate change mitigation strategy, offering a pathway to actively remove atmospheric CO2. This comprehensive review synthesizes advancements in DAC technologies, with a particular emphasis on the pivotal role of nanostructured solid sorbent materials. The work critically evaluates the characteristics, performance, and limitations of key nanomaterial classes, including metal–organic frameworks (MOFs), covalent organic frameworks (COFs), zeolites, amine-functionalized polymers, porous carbons, and layered double hydroxides (LDHs), alongside solid-supported ionic liquids, highlighting their varied CO2 uptake capacities, regeneration energy requirements, and crucial water sensitivities. Beyond traditional temperature/pressure swing adsorption, the review delves into innovative DAC methodologies such as Moisture Swing Adsorption (MSA), Electro Swing Adsorption (ESA), Passive DAC, and CO2-Binding Organic Liquids (CO2 BOLs), detailing their unique mechanisms and potential for reduced energy footprints. Despite significant progress, the widespread deployment of DAC faces formidable challenges, notably high capital and operational costs (currently USD 300–USD 1000/tCO2), substantial energy demands (1500–2400 kWh/tCO2), water interference, scalability hurdles, and sorbent degradation. Furthermore, this review comprehensively examines the burgeoning global DAC market, its diverse applications, and the critical socio-economic barriers to adoption, particularly in developing countries. A comparative analysis of DAC within the broader carbon removal landscape (e.g., CCS, BECCS, afforestation) is also provided, alongside an address to the essential, often overlooked, environmental considerations for the sustainable production, regeneration, and disposal of spent nanomaterials, including insights from Life Cycle Assessments. The nuanced techno-economic landscape has been thoroughly summarized, highlighting that commercial viability is a multi-faceted challenge involving material performance, synthesis cost, regeneration energy, scalability, and long-term stability. It has been reiterated that no single ‘best’ material exists, but rather a portfolio of technologies will be necessary, with the ultimate success dependent on system-level integration and the availability of low-carbon energy. The review paper contributes to a holistic understanding of cutting-edge DAC technologies, bridging material science innovations with real-world implementation challenges and opportunities, thereby identifying critical knowledge gaps and pathways toward a net-zero carbon future. Full article
(This article belongs to the Special Issue Porous Carbon Materials: Preparation and Application)
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28 pages, 4382 KiB  
Article
Chlorella vulgaris-Derived Biochars for Metribuzin Removal: Influence of Thermal Processing Pathways on Sorption Properties
by Margita Ščasná, Alexandra Kucmanová, Maroš Sirotiak, Lenka Blinová, Maroš Soldán, Jan Hajzler, Libor Ďuriška and Marián Palcut
Materials 2025, 18(14), 3374; https://doi.org/10.3390/ma18143374 - 18 Jul 2025
Viewed by 336
Abstract
Carbonaceous sorbents were prepared from Chlorella vulgaris via hydrothermal carbonization (200 °C and 250 °C) and slow pyrolysis (300–500 °C) to assess their effectiveness in removing the herbicide metribuzin from water. The biomass was cultivated under controlled laboratory conditions, allowing for consistent feedstock [...] Read more.
Carbonaceous sorbents were prepared from Chlorella vulgaris via hydrothermal carbonization (200 °C and 250 °C) and slow pyrolysis (300–500 °C) to assess their effectiveness in removing the herbicide metribuzin from water. The biomass was cultivated under controlled laboratory conditions, allowing for consistent feedstock quality and traceability throughout processing. Using a single microalgal feedstock for both thermal methods enabled a direct comparison of hydrochar and pyrochar properties and performance, eliminating variability associated with different feedstocks and allowing for a clearer assessment of the influence of thermal conversion pathways. While previous studies have examined algae-derived biochars for heavy metal adsorption, comprehensive comparisons targeting organic micropollutants, such as metribuzin, remain scarce. Moreover, few works have combined kinetic and isotherm modeling to evaluate the underlying adsorption mechanisms of both hydrochars and pyrochars produced from the same algal biomass. Therefore, the materials investigated in the present work were characterized using a combination of standard physicochemical and structural techniques (FTIR, SEM, BET, pH, ash content, and TOC). The kinetics of sorption were also studied. The results show better agreement with the pseudo-second-order model, consistent with chemisorption, except for the hydrochar produced at 250 °C, where physisorption provided a more accurate fit. Freundlich isotherms better described the equilibrium data, indicating heterogeneous adsorption. The hydrochar obtained at 200 °C reached the highest adsorption capacity, attributed to its intact cell structure and abundance of surface functional groups. The pyrochar produced at 500 °C exhibited the highest surface area (44.3 m2/g) but a lower affinity for metribuzin due to the loss of polar functionalities during pyrolysis. This study presents a novel use of Chlorella vulgaris-derived carbon materials for metribuzin removal without chemical activation, which offers practical benefits, including simplified production, lower costs, and reduced chemical waste. The findings contribute to expanding the applicability of algae-based sorbents in water treatments, particularly where low-cost, energy-efficient materials are needed. This approach also supports the integration of carbon sequestration and wastewater remediation within a circular resource framework. Full article
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20 pages, 1303 KiB  
Review
The Role of Nanomaterials in the Wearable Electrochemical Glucose Biosensors for Diabetes Management
by Tahereh Jamshidnejad-Tosaramandani, Soheila Kashanian, Kobra Omidfar and Helgi B. Schiöth
Biosensors 2025, 15(7), 451; https://doi.org/10.3390/bios15070451 - 14 Jul 2025
Viewed by 466
Abstract
The increasing prevalence of diabetes mellitus necessitates the development of advanced glucose-monitoring systems that are non-invasive, reliable, and capable of real-time analysis. Wearable electrochemical biosensors have emerged as promising tools for continuous glucose monitoring (CGM), particularly through sweat-based platforms. This review highlights recent [...] Read more.
The increasing prevalence of diabetes mellitus necessitates the development of advanced glucose-monitoring systems that are non-invasive, reliable, and capable of real-time analysis. Wearable electrochemical biosensors have emerged as promising tools for continuous glucose monitoring (CGM), particularly through sweat-based platforms. This review highlights recent advancements in enzymatic and non-enzymatic wearable biosensors, with a specific focus on the pivotal role of nanomaterials in enhancing sensor performance. In enzymatic sensors, nanomaterials serve as high-surface-area supports for glucose oxidase (GOx) immobilization and facilitate direct electron transfer (DET), thereby improving sensitivity, selectivity, and miniaturization. Meanwhile, non-enzymatic sensors leverage metal and metal oxide nanostructures as catalytic sites to mimic enzymatic activity, offering improved stability and durability. Both categories benefit from the integration of carbon-based materials, metal nanoparticles, conductive polymers, and hybrid composites, enabling the development of flexible, skin-compatible biosensing systems with wireless communication capabilities. The review critically evaluates sensor performance parameters, including sensitivity, limit of detection, and linear range. Finally, current limitations and future perspectives are discussed. These include the development of multifunctional sensors, closed-loop therapeutic systems, and strategies for enhancing the stability and cost-efficiency of biosensors for broader clinical adoption. Full article
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20 pages, 2436 KiB  
Article
Advanced Hybrid Nanocatalysts for Green Hydrogen: Carbon-Supported MoS2 and ReS2 as Noble Metal Alternatives
by Maria Jarząbek-Karnas, Zuzanna Bojarska, Patryk Klemczak, Łukasz Werner and Łukasz Makowski
Int. J. Mol. Sci. 2025, 26(14), 6640; https://doi.org/10.3390/ijms26146640 - 10 Jul 2025
Viewed by 527
Abstract
One of the key challenges in commercializing proton exchange membrane (PEM) electrolyzer technology is reducing the production costs while maintaining high efficiency and operational stability. Significant contributors to the overall cost of the device are the electrode catalysts with IrO2 and Pt/C. [...] Read more.
One of the key challenges in commercializing proton exchange membrane (PEM) electrolyzer technology is reducing the production costs while maintaining high efficiency and operational stability. Significant contributors to the overall cost of the device are the electrode catalysts with IrO2 and Pt/C. Due to the high cost and limited availability of noble metals, there is growing interest in developing alternative, low-cost catalytic materials. In recent years, two-dimensional transition metal dichalcogenides (2D TMDCs), such as molybdenum disulfide (MoS2) and rhenium disulfide (ReS2), have attracted considerable attention due to their promising electrochemical properties for hydrogen evolution reactions (HERs). These materials exhibit unique properties, such as a high surface area or catalytic activity localized at the edges of the layered structure, which can be further enhanced through defect engineering or phase modulation. To increase the catalytically active surface area, the investigated materials were deposited on a carbon-based support—Vulcan XC-72R—selected for its high electrical conductivity and large specific surface area. This study investigated the physicochemical and electrochemical properties of six catalyst samples with varying MoS2 and ReS2 to carbon support ratios. Among the composites analyzed, the best sample on MoS2 (containing the most carbon soot) and the best sample on ReS2 (containing the least carbon soot) were selected. These were then used as cathode catalysts in an experimental PEM electrolyzer setup. The results confirmed satisfactory catalytic activity of the tested materials, indicating their potential as alternatives to conventional noble metal-based catalysts and providing a foundation for further research in this area. Full article
(This article belongs to the Section Materials Science)
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