Capacitive deionization (CDI) represents a novel technology for the desalination and purification of seawater. Selecting the appropriate electrode material is crucial, with carbon electrodes frequently employed owing to their high specific surface area, extensive porous structure, and environmentally sustainable nature. This study presents a nitrogen-doped porous carbon, derived from household waste, which demonstrates outstanding electrochemical and desalination performance. The purified chitosan was mixed with a specific ratio of CaCO3 and carbonized at 800 °C to produce chitosan porous carbon (CPC-T). To verify the role of the templating agent, its performance was compared with chitosan porous carbon (CPC) prepared by direct carbonization. CPC-T possesses more mesoporous structures (31.25%), shortening ion transport pathways and significantly enhancing charge transfer rates. The nitrogen-rich doping (8.65 at%) provides numerous active sites and excellent conductivity, making it highly appropriate for capacitive deionization applications. Compared to CPC prepared without a templating agent, CPC-T has a higher specific capacitance (101.5 F g− 1 at a scan rate of 2 mV s− 1) and good cycling stability. The CDI cell made from it exhibits a salt adsorption capacity (SAC) of 25.8 mg g− 1 for 500 mg L− 1 NaCl solution at an applied voltage of 1.4 V, retaining 88% capacity after 50 adsorption–desorption cycles, demonstrating excellent desalination regeneration performance. Additionally, among different concentrations of salt solutions, the CPC-T material shows the best desalination performance for the test solution at a concentration of 500 mg L− 1. For different solute ions, the CDI cell with this material as the electrode exhibits excellent desalination performance for Ca2+, with a SAC value of up to 34.02 mg g− 1. This is a self-doped porous carbon material that significantly outperforms traditional carbon-based materials.

This paper evaluates the effect of two kinds of recycled coarse aggregate with different sized particles on the performance of concrete. The test program is introduced, which investigated the compressive strength, axial compressive strength, the mass loss rate of concrete specimens after a freeze-thaw cycle and dynamic elasticity modulus change. The results show that the mechanical properties of the concrete decreased when it was prepared with recycled aggregate having the same size as that of the natural aggregates. The strength of the concrete with large-size recycled aggregate increased, and then decreased as the blend proportion rose above 50%. The strength of concrete incorporating oversized recycled aggregates exhibited a trend of rising and then falling with increasing mixing ratio. The 28-day compressive strength reached 45Mpa when the mixing amount was 50%. The durability of the large-size recycled aggregate was also found to improve compared with the freezing and thawing cycle experiments. These results provide a reference for research on the performance of recycled aggregate concrete.

This study details the synthesis and characterization of phosphorus-sulfur co-doped graphitic carbon nitride quantum dots (PSQ) and their integration into g-C3N4 (CN) to form PSQ/CN composites for the enhanced photocatalytic reduction of Cr(VI) and fluorescence detection. Incorporating PSQ into CN was found to significantly improve light absorption, narrow the band gap, and enhance charge separation efficiency. Notably, the composite material exhibits superior photocatalytic performance, especially in acidic environments. Photocatalytic assessments utilizing Cr(VI) demonstrated that the PSQ/ CN composite outperformed both undoped and singly doped materials, indicating its superior photocatalytic activity. Additionally, phosphorus-sulfur co-doping markedly increased the fluorescence quantum yield of PSQ. The fluorescence intensity exhibited a linear decrease with increasing Cr(VI) concentrations, enabling sensitive and selective detection of Cr(VI) with a detection limit as low as 1.69 μmol/L. Collectively, the PSQ/CN composite and PSQ highlight their potential for photocatalysis and fluorescence-based detection of Cr(VI), providing high sensitivity, selectivity, and synergistic interactions within the composite material.

The study presents a framework for the sustainable carbon-based nanomaterials, focusing on Carbon Nano Tubes (CNTs). The framework integrates performance, hazard, and economic considerations toward the development of CNT-enabled products. Through Life Cycle Analysis (LCA) and environmental degradation studies, the research highlights the energy-intensive nature of CNT production, the persistence of CNTs in the environment, and the associated ecotoxicity risks. Functionalization of CNTs is emphasized as a crucial strategy to enhance biodegradability and reduce toxicity. The study also addresses the economic trade-offs, noting that while CNTs offer superior functional performance, their high production costs and energy demands must be carefully managed. The proposed framework aims to ensure that CNTs maximize their benefits while minimizing their environmental and health impacts, thereby supporting the sustainable advancement of carbon nanomaterials in various applications. The study found that CNT production is highly energy-intensive, but scaling up can improve efficiency. CNTs persist in the environment, with partial degradation, indicating potential long-term ecological risks. Functionalization enhances biodegradability and reduces toxicity, helping to balance performance with sustainability.

To optimize the electrochemical properties of Ni-rich cathode materials, CPAN@SC-NCM811 is prepared via surface modification of single-crystalline LiNi0.8Co0.1Mn0.1O2 cathode material by adding 1, 2 and 3 wt.% of polyacrylonitrile, respectively. Significantly, the results obtained from X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) verify the successful synthesis of CPAN@SC-NCM811 cathode, which exhibits better electrochemical properties compared to SC-NMC811. After thorough milling and calcination of 2 wt.% polyacrylonitrile with SC-NCM811, the initial discharge specific capacity of prepared S2 sample is 197.7 mAh g− 1 and the capacity retention reached 89.2% after 100 cycles at a rate of 1.0 C. Furthermore, the S2 sample exhibits superior rate performance compared to the other three samples, in which these superior electrochemical properties are largely attributed to the optimal ratio of conductive cyclized polyacrylonitrile coatings. Overall, this work offers guidelines for modifying the surface of SC-NCM811 cathode materials for lithium-ion batteries with exceptional cycling and rate performance.

As a key component of composite materials, the interface quality is crucial for determining the mechanical properties of composites. Carbon fiber sizing treatment significantly enhances the fiber-matrix interface, a process extensively utilized in the carbon fiber industry. This study synthesized an environmentally friendly waterborne polyurethane sizing agent and investigated the impact of molecular weight, a critical factor, on composite performance by varying the soft segment type in the polyurethane. This research provides insights into cost-effective and eco-friendly surface treatment methods for carbon fibers and the design of robust interface structures.

In recent years, there has been growing interest in the potential applications of carbon-based non-metallic catalysts in various fields, such as electrochemical energy storage, electrocatalysis, thermal catalysis, and photocatalysis, owing to their unique physical and chemical properties. Modifying carbon catalyst surfaces or incorporating non-metallic heteroatoms, such as nitrogen (N), phosphorus (P), boron (B), and sulfur (S), into the carbon structure has emerged as a promising approach to improve the catalytic performance. This method enables the adjustment of the electronic structure of the carbon catalyst's surface, leading to the formation of new active sites or the reduction of side reactions, ultimately enhancing the catalyst's performance. Here, the preparation methods for doped non-metallic heteroatom carbon catalysts have been systematically explored, encompassing techniques, such as impregnation, pyrolysis, chemical vapor deposition (CVD), and templating. Finally, the existing challenges in the application of non-metallic atomic catalysts have been discussed, insights into potential future development opportunities and new preparation methods of carbon catalysts in the future have been offered.

With the increasing demand for energy conservation and emissions reduction in the shipping industry, suctionbased turbine sails have emerged as a novel wind energy utilization technology and have become a research hotspot. This study focuses on the aerodynamic performance of suction-based turbine sails with the aim of investigating the effects of suction intensity and suction port position on their aerodynamic characteristics. By employing Computational Fluid Dynamics (CFD) numerical simulations using the Re-Normalization Group (RNG) k–ε turbulence model and the SIMPLE algorithm, this study provides a detailed analysis of lift and drag coefficients, pressure distribution, and vorticity distribution under various combinations of suction intensity (γ) and suction port position (α). The results show that variations in suction intensity significantly affect the lift and drag characteristics of the turbine sail, while changes in the suction port position directly influence the attachment and separation behavior of airflow on the sail surface. Furthermore, a synergistic effect is observed between γ and α—their interaction not only alters the flow distribution but also plays a critical role in determining the overall performance of the turbine sail.By comprehensively considering the influence of these two factors, the study draws key conclusions for optimizing the design of suction-based turbine sail, providing valuable theoretical insights and technical guidance for their practical application in wind-assisted marine propulsion.

The escalating impacts of climate change are compelling individuals to flee their homes, giving rise to a new category of refugees known as climate refugees. Despite clear evidence linking climate change to forced migration, the protection of these refugees’ human rights remains unaddressed by any existing international legal framework. This paper explores the necessity of embracing a new comprehensive international legal framework tailored to climate refugees. It advocates for a legal framework that addresses prevention and remedies the issues faced by climate refugees and ensures their human rights are safeguarded. We also argued that the Comprehensive International Legal Framework should have a collective obligation to safeguard the rights of climate refugees on the global scale and to provide a solution that integrates the various rules of law, meets humanitarian needs, and is tailored to the protection of the rights of climate refugees.

This paper is devoted to synthesizing a new type of CDs (carbon dots) with excellent NIR (near-infrared) emission in a biological water environment synthesized from small molecules. Citric acid was adopted as the precursor and treated by one-pot hydrothermal process in DMF solution with the assistance of a microwave. Urea (MH) and ammonium fluoride (MF) were adopted as nitrogen sources to synthesize two types of CDs, respectively. These conditions contributed to generate nanostructured carbon with a higher content of Pyrrolic-N, enrich the functional groups, and exfoliate the ordered layerstacking structure, which finally contributed to the higher NIR absorption band at 808 nm. The physicochemical properties and photothermal conversion ability were fully evaluated by UV–Vis-NIR (ultraviolet–visible light-NIR) absorption and photothermal experiments. MF possessed stronger absorption property and temperature-rising effect in the NIR region than MH, but both exhibited desirable photothermal stability. Next, the in vitro and in vivo experiments demonstrated that both MF and MH exhibited no significant toxicity for cells. NIR irradiation on CDs solution displayed an excellent killing effect on HeLa (breast cancer) and MCF7 (cervical cancer) cells but strongly depended on the concentration of CDs. MH had a weaker killing effect on MCF7 cells compared with MF in the same concentration. But HeLa cells suffered death from lower concentration of MH under NIR irradiation. Both MH and MF exhibited excellent therapy effects and no obvious tissue damage for these major organs of nude mice and BALB/C mice. Above all, both MF and MH with excellent photothermal effect under NIR irradiation had desirable NIR-triggered therapeutic effect on MCF7 and HeLa cells, while they also exhibited good biocompatibility without NIR irradiation.