Efficient Carbon Research Articles

Q-learning assisted multi-objective evolutionary optimization for low-carbon scheduling of open-pit mine trucks

Mine trucks, as the core equipment of discontinuous open-pit mining technology, account for high transportation costs and vast quantities of greenhouse gases. In order to improve transportation efficiency and decrease carbon emissions, rationally scheduling shovel-truck pairs is a necessary issue. Previous studies give less consideration on carbon emissions of trucks that varies with road and driving conditions. To overcome the shortage, a constraint bi-objective optimization model is built for low-carbon scheduling problem of open-pit mine trucks, in which minimizing both idle time and carbon emissions of trucks are taken as the objectives. More especially, the limits on working time, traffic volume and the number of trucks are modeled as the constraints. Carbon emissions is formulated by multistage nonlinear function that takes road condition, load and driving state of trucks into account. As the problem-solver, Q-learning assisted multi-objective evolutionary algorithm is put forward. Four evolution states are defined by analyzing the improvement on feasibility and convergence of the population, and four problem-specific evolution operators are designed to meet different demands of the evolution. Q-learning-based selection strategy is proposed to select the most appropriate operator, with the purpose of improving the evolution efficiency. Experimental results on the real-world instances expose that the proposed algorithm outperforms the other state-of-the-art algorithms significantly.

Response of Carbon and Water Use Efficiency to Climate Change and Human Activities in Central Asia

Carbon use efficiency (CUE) and water use efficiency (WUE) are key metrics for quantifying the coupling between terrestrial ecosystem carbon and water cycles. The impacts of intensifying climate change and human activities on carbon and water fluxes in Central Asian vegetation remain unclear. In this study, the CUE and WUE in Central Asia from 2001 to 2022 were accurately estimated with the help of the Google Earth Engine (GEE) data platform; the Theil–Sen median slope estimation combined with the Manna–Kendall significance test and partial derivative analysis were used to investigate the CUE and WUE trends and their responses to climate change and human activities. CUE and WUE show overall declining trends with significant spatial variability. Among meteorological factors, vapor pressure deficit and temperature show the strongest correlation with CUE, while precipitation and temperature are most correlated with WUE. Compared to human activities, climate change has a greater impact on CUE and WUE, mainly exerting a negative influence. Human activities are the main drivers in regions with developed agriculture, such as oases, farmlands, and areas near rivers and lakes. This study provides scientific references for the optimization of water and soil resources and the integrated regional environmental management in Central Asia.

Enhanced nitrogen removal for low C/N wastewater via preventing futile carbon oxidation and augmenting anammox

Efficient carbon use is crucial for biological nitrogen removal. Traditional aerobic processes can waste carbon sources, exacerbating carbon deficiency. This study explores an anaerobic/oxic/anoxic system with sludge double recirculation to improve nitrogen removal in low C/N wastewater. This system integrated aerobic nitrification after the carbon intracellular storage, separating carbon and nitrogen by denitrifying glycogen-accumulating organisms (DGAOs) with endogenous partial denitrification and Anammox within the anoxic units. A significant efficiency of 91.02±7.01% chemical oxygen demand (COD) was converted into intracellular carbon in anaerobic units, significantly reducing carbon futile oxidation in the aerobic units by effectively separating COD from ammonia. Intracellular storage of carbon sources and microbial adaptation to carbon scarcity prevent futile oxidation of COD in the aerobic units even with short-term high dissolved oxygen (DO), thereby enhancing nitrogen removal under anoxic conditions with sufficient intracellular carbon source. The microbial analysis identified Candidatus Brocadia as the dominant anammox bacteria, in combination with the activity of DGAOs and other related microbial communities, accounting for 37.0% of the TN removal. Consequently, the system demonstrated remarkable nitrogen removal efficiencies, achieving 81.3±3.3% for total nitrogen (TN) and 98.5±0.9% for ammonia nitrogen while maintaining an effluent COD concentration of 17.2±9.1 mg/L, treating the low C/N of 4.18 in the influent wastewater. The findings in this study provide a sustainable and energy-saving technique for conventional WWTPs to meet strict discharge standards by avoiding futile oxidation of COD and encouraging anammox contributions.

Machine learning-based techno-econo-environmental analysis of CO2-to-olefins process for screening the optimal catalyst and hydrogen color

CO2 to light olefins (CTLO) is an attractive strategy for CO2 fixation to obtain high-value-added chemical products. Selecting the optimal catalyst and hydrogen source for the process has become increasingly challenging due to the wide range of developed catalysts and diverse hydrogen sources available. Herein, this study proposes a machine learning-based techno-econo-environmental analysis framework for screening catalysts and hydrogen colors for the CTLO process. The preferred machine learning model is employed to screen the most promising catalyst for the CTLO process, which is then applied to accomplish the conceptual design of the entire process to obtain essential material and energy balance results by process modeling and simulation. Finally, the techno-econo-environmental performance of the CTLO processes using various colored hydrogen are compared to provide more informed choices. The results indicate the extreme gradient boosting model exhibits superior predictive accuracy, making it suitable for integrating with the genetic algorithm to screen the optimal catalyst for the CTLO process. After multi-objective optimization, an optimal Fe-based catalyst is screened and used for the modeling and simulation of the CTLO process due to its highest light olefins yield (36.43%). The carbon, hydrogen, and exergy utilization efficiencies of the CTLO process considering solely the target light olefins are 59.58%, 21.71%, and 40.41%, respectively. After evaluating the impact of different H2 colors on the total operating cost, unit production cost, and minimum selling price of the CTLO process, it was found the CTLO process using gray H2 generated by coke oven gas and coal gasification technologies exhibits the most favorable cost-effectiveness and optimal market price compared to alternative production scenarios. However, using green H2 proves highly advantageous for the CTLO process in attaining comprehensive negative carbon emissions throughout its lifecycle. Moreover, it anticipates the influence of technological advancements and market fluctuations on the market competitiveness of CTLO processes with diverse hydrogen colors.

Does regional economic development drive sustainable grain production growth in China? Evidence from spatiotemporal perspective on low-carbon total factor productivity

Contrary to conventional expectations, the impact of economic development on food green efficiency exhibits pronounced regional heterogeneity. This study utilizes total factor productivity (TFP) as a key metric, establishing a model for carbon emissions from grain production and developing a framework for measuring grain low-carbon TFP growth. Employing the undesirable super-slacks-based measure (SBM) and the Malmquist-Luenberger (ML) index, we assess the low-carbon TFP growth across 31 Chinese provinces from 2000 to 2021. The Dagum–Gini coefficient and variance decomposition are applied to analyze disparities from both regional and structural perspectives. An econometric model further validates the influence of economic development on low-carbon TFP growth. Our findings reveal that China’s technical efficiency (TE) and low carbon TE initially show a declining trend, with the gap between them narrowing over time. The eastern region consistently demonstrates high low-carbon TE, while the northeastern region lags. All regions exhibit positive low-carbon TFP growth, with efficiency change (EC) significantly contributing to this growth. Although economic development generally fosters low-carbon TFP growth, marked regional heterogeneity persists. Interestingly, certain traditionally economically developed regions, such as the eastern region, exert a significantly negative impact on low-carbon TFP growth. Balancing economic development with low-carbon TFP growth remains an ongoing challenge that necessitates effective management strategies.

Reusable metal-free mesoporous carbon-catalyzed reductive N-formylation of nitroarenes and quinolines

The high-value transformation of nitrogen-containing compounds through a facile, cost-effective, and eco-friendly one-pot strategy holds significant importance. However, this process typically involves the use of metal catalysts and is limited by low activity as well as the requirement of high temperature and pressure. Herein, we describe a general and efficient metal-free N-doped mesoporous carbon material using well-defined ligand 1,10-phenanthroline as the precursor and silica colloid as the hard template. Formic acid is both a reducing agent and a formylation reagent, and structurally distinct mono- or multi-substituted nitroarenes and quinolines can be selectively N-formylation in a one-pot method. The catalyst can be easily recovered without observable loss of efficiency for ten consecutive uses. The control experiments and density functional theory (DFT) calculations indicate that formic acid mainly obtains active hydrogen in the form of O–H bond cleavage, which benefits from the strong adsorption and enhanced activity generated by the interaction between graphitic nitrogen species in the catalyst and formic acid. The excellent catalytic performance of the meso-phen-X catalyst is attributed to the synergistic effect of graphitic N and large specific surface area, providing a promising method for the development of non-metallic catalyst-modified carbon materials.

Sulfate-activated mineral carbonation of olivine minerals with mechanisms explained by shrinking core models and by machine learning algorithm

Direct aqueous mineral carbonation of olivine minerals has been extensively investigated in the past. However, the effect of inorganic electrolytes, particularly sodium sulfate (Na2SO4), on mineral carbonation rate has not been investigated yet. In this work, we report experimental results on the CO2 uptake rate of ultrafine olivine-rich rocks using Na2SO4 and sodium chloride (NaCl) as inorganic catalysts under hydrothermal conditions. The reaction mechanism was explained using both a shrinking core model and a machine learning model. One major and unexpected finding was that the use of Na2SO4 significantly increased the carbonation efficiency compared to the baseline with and without using sodium chloride (NaCl) as an inorganic electrolyte. The results showed that an increase in the carbonation kinetics in the presence of Na2SO4 was evident, particularly at a temperature range of 145–185 °C. At this temperature range, the reaction kinetics are predominantly governed by the product layer diffusion control mechanism. The presence of Na2SO4 electrolyte likely contributed to a promoted dissolution of silica and divalent ions from the hosting rocks/minerals. Results obtained from machine learning modelling confirmed that both the temperature and Na2SO4 additive were key parameters for mineral carbonation compared with other process variables. The present study demonstrates the catalyzing role of Na2SO4 in direct aqueous mineral carbonation of olivine minerals.

Carbon negative methanol production for CO2 utilization: Process design and 4E analysis

To produce alternative fuel and reduce CO2 emissions, the CO2-to-methanol (CTM) process is currently considered to be an effective technical pathway. However, the base CTM process suffers from high energy consumption and low carbon efficiency. Therefore, this work proposed an optimized CTM process integrating double-effect distillation, waste heat recovery, and H2 stripping technologies. Compared to the base CTM process, the optimized CTM process significantly enhances the techno-economic-environmental performances. Meanwhile, it realizes zero external heat requirements and negative carbon emissions. In order to quantitatively evaluate the improvements in the process performances, we conducted detailed technical-economic-environmental analyses. From the technical perspective, the energy efficiency and exergy efficiency of the optimized CTM process are 10.28% and 4.84% higher than that of the base CTM process, respectively. From the economic perspective, the methanol production cost in the optimized CTM process is lower by 18.40 $/tonne MeOH compared to the base CTM process. As for the environmental perspective, the GWP of the optimized CTM process is reduced by 336.42 kg CO2-eq/tonne MeOH compared with the base CTM process. In summary, the optimized CTM process offers an energy-efficient, cost-saving, and environment-friendly solution for CO2 conversion.

Mechanism of biochar-Cu-based catalysts construction and its electrochemical CO2 reduction performance

Electrochemical CO2 reduction can convert CO2 into high-value-added products for special forms of energy storage and efficient carbon utilization for renewable electricity. To investigate the influence of biochar-Cu-based catalysts properties on electrochemical CO2 reduction performance, Cu is loaded onto rice husk-based biochar by impregnation method combined with pyrolysis and calcination in this study. The three synthesized biochar-Cu-based catalysts are tested for activity and electrochemical CO2 reduction performance in Flow Cell. The results show that biochar's properties, such as its high specific surface area, rich pore structure, and adjustable pore structure, provide sufficient sites for CO2 reduction. Urea can relatively increase the copper loading by 44 %, but it will also increase the clustering of copper. In the reduction performance test, the current density of char-Cu-700 is 2.08 times higher than that of char-Cu and 1.45 times higher than char-Cu-N at a reduction potential of -0.45 (V vs. RHE). The current density enhancement of the catalyst loaded on biochar with Cu particle size of 10 nm is about 50 % higher than that of the catalyst with a particle size of 20 nm. It indicates that the smaller the particle size of Cu at the nanoscale, the lower the average coordination of surface atoms and the greater the catalyst's reactivity. This study provides novel ideas for synthesizing biochar-Cu-based catalysts, lays part of the theoretical foundation for using biochar-Cu-based catalysts for electrochemical CO2 reduction, and provides experimental support for optimizing the catalyst structure.

Optimization and performance evaluation of a novel nano-zeolite amended pure oxygen-driven membrane aerated biofilm reactor (Z-PO-MABR) for enhanced carbon and nitrogen removal from high-strength wastewater

High-strength wastewater presents significant environmental challenges. Membrane-aerated biofilm reactor (MABR) technology, enhanced by pure oxygen, improves treatment efficiency. Additionally, nano-zeolite-based techniques have shown promise. This study introduces a novel nano-zeolite amended pure oxygen-based MABR system (Z-PO-MABR), combining the benefits of pure oxygen and nano-zeolite. A bench-scale Z-PO-MABR was developed and tested under various conditions to optimize the operation. Optimization achieved high removal rates of organic carbon (98 %) and total nitrogen (96.9 %) with 72 g/Lr of nano-zeolite after 9 h. The Z-PO-MABR system outperforms conventional and pure oxygen-based MABRs, demonstrating greater efficiency in continuous and batch flow modes. The optimized parameters maximize carbon degradation and support microbial growth, offering an eco-sustainable solution for high-strength wastewater treatment. The Z-PO-MABR system is proposed as a promising method for efficient carbon removal and complete nitrogen release. Thus, the study strongly nominates the Z-PO-MABR as an effective treatment system.

Zeolite A/CuO embedded natural rubber foam for efficient carbon dioxide capture in the packed column

Zeolite A/CuO embedded natural rubber foam for efficient carbon dioxide capture in the packed column

Urban land use optimization prediction considering carbon neutral development goals: a case study of Taihu Bay Core area in China

BackgroundGiven the increasing commitment of numerous nations to achieving future carbon neutrality, urban development planning that integrating carbon storage considerations plays a crucial role in enhancing urban carbon efficiency and promoting regional sustainable development. Previous studies have indicated that optimizing land use structure and quality is essential for regional carbon storage management. Taking the core area of Taihu Bay as study area, this study innovatively combined high-precision urban 3D data to account for the whole urban carbon pools of buildings, vegetation, soils, water. Then, multi-objective linear programming model and PLUS (Patch-generating Land Use Simulation) model were applied at patch scale to assess and compare carbon storage in various scenarios, considering both carbon storage maximization and urban development requirements.ResultsThe results were presented as follows. (1) Urban woodland carbon pool accounts for only a fraction of total carbon pool, and the role of soil and building carbon pools cannot be ignored. (2) Compared with the current situation, the carbon-growth optimized scenario will lead to the increase of total carbon storage by 38,568.31 tons. (3) Carbon-growth optimized scenario has reduced carbon storage in Woodland, Cropland, Village, Water compared to the Natural growth scenario, but has increased carbon storage in Garden plots, Street, Urban district, Town and other areas.ConclusionsTherefore, we find that for fast-growing cities, rationally planning built-up areas and woodland areas can achieve the twin goals of economic development and maximizing regional carbon storage. Furthermore, the implementation of new energy policies and projects such as green roofs can help to achieve regional carbon neutrality. The study provides new insights into the accounting of carbon pools within cities and the simulation of fine-grained land use planning based on the dual objectives of carbon stock maximization and urban development.

Mechanistic insights into the use of flotation tail coal for enhanced water electrolysis in hydrogen production

Coal-assisted water electrolysis for hydrogen production (CAWE) is a promising method for the efficient utilization of coal resources and the sustainable generation of hydrogen. However, identifying a cost-effective and efficient carbon source remains a critical and ongoing challenge. This study proposes the use of flotation tail coal as a novel and efficient carbon source for water electrolysis. Through a combination of electrochemical experiments, thermodynamic analysis, and comprehensive material characterization techniques, this research explores the effectiveness of tail coal-assisted water electrolysis for hydrogen production (TCAWE) in enhancing hydrogen production efficiency. It is found that the catalytic effect of minerals, particularly iron and manganese ions, is instrumental in significantly reducing energy consumption and enhancing the anodic oxidation reactions in the CAWE process. Flotation tail coal, with its high content of these catalytic minerals and favorable hydrophilic surface properties, not only lowers the electrolysis voltage but also increases the hydrogen yield compared to traditional coal sources. This research innovatively demonstrates that utilizing flotation tail coal in water electrolysis offers a dual benefit: it provides a cost-effective, abundant carbon source while promoting a more efficient and sustainable hydrogen production process. Additionally, this approach is expected to facilitate the resource utilization of waste flotation tail coal.

Quantifying organic carbon burial rates and stocks in seagrass meadow sediments influenced by sargassum-brown tides

Seagrass meadow sediments are efficient organic carbon (Corg) sinks and can store Corg for hundreds of years. The temporal variation of Corg burial rates and stocks over recent decades at nearshore seagrass meadows in the Puerto Morelos Reef Lagoon, Mexico, was evaluated in 210Pb-dated sediment cores from nearshore meadows dominated by Thalassia testudinum. The sediments were predominantly sandy (>52% sand) rich in carbonate grains (11.8–12.5% Cinorg) with minor Corg (0.24–1.12%) and Norg (0.02–0.13%) concentrations. The C:N ratio (9.4–13.0) indicated that marine-derived Corg was prevalent. Corg stocks in the upper 30 cm sediment were 15.9 ± 3.0–24.8 ± 4.6 Mg ha−1. Sedimentary mass accumulation rates (MAR) (0.7–1.5 g cm−2 yr−1) were higher than those previously recorded in seagrass sediments from the reef lagoon and other parts of the world. The highest MAR values, recorded in 2015 (±0.13) and 2018 (±0.03), coincided with the peak sargassum influx years. MAR and Corg burial rates (11.4–133 g m−2 yr−1) were correlated (r2 = 0.76), indicating that the massive influxes of sargassum have accelerated Corg burial rates in the region since 2015. This study marks the initial evaluation of the interaction between the massive influx of sargassum, MAR, and Corg burial rates in seagrass sediments, potentially laying the groundwork for future extended monitoring initiatives.

Amylopectin from maize-derived carbonized polymer dots as a novel high-efficiency antioxidant for periodontitis treatment

Periodontitis is a common chronic inflammatory disease and the local accumulation of excessive reactive oxygen species (ROS) could cause oxidative damage to periodontal tissues. Thus, antioxidative therapy is considered to be the promising strategy for treating periodontitis. However, highly efficient antioxidant activity of biomaterials with low cost, ease of synthesis, and good biocompatibility are still highly desired. Here amylopectin from maize (AFM)-derived carbonized polymer dots (AFM-CPDs-240) with excellent antioxidant activity, good water solubility and biosafty is parepared. Detailed characterizations identify that the antioxidant properties and formation mechanism of AFM-CPDs, and antioxidant activity of AFM-CPDs-240 is much higher than Trolox (a hydrophilic derivative of vitamin E) due to the large contents of conjugated C=C and C=O. Besides, in vitro and in vivo experiments suggest AFM-CPDs-240 could effectively alleviate inflammatory response, inhibit alveolar bone resorption and promote bone formation, showing excellent therapeutic effects on periodontitis. Moreover, the label-free proteomics and western blot results demonstrate AFM-CPDs-240 could accelerate the recovery of periodontitis by blocking TLR4/NF-κB (Toll-like receptor 4/ nuclear factor-kappa B) signaling pathway. This study will develop a simple approach to design highly efficient antioxidant carbon dots with good biocompatibility, and also provide a new promising nanoplatform for treating diseases associated with ROS.

Adsorption efficiency and photocatalytic activity of silver sulphide-activated carbon (Ag2S-AC) composites

BackgroundThis study investigates the adsorption efficiency and photocatalytic activity of silver sulphide-activated carbon (Ag2S-AC) composites derived from ground coffee waste (GCW). MethodsIn this work, GCW was preceding to carbonized at 500 ± 2°C for hours and formed biochar. Then, GCW was subjected to activation using hydrochloric acid (HCl), phosphoric acid (H3PO4) and potassium hydroxide (KOH). The mixture was left to soak for 24 h at room temperature, followed by carbonization at 350 and 500˚C. In the meantime, the silver sulphide (Ag2S) was synthesized by using an ion exchange method. Sodium sulphide (Na2S) was used as sulphur source and mixed with silver nitrate (AgNO3) and sodium citrate (NaCit) for two hours, then dried in oven at 50 ± 2°C for 10 h. Next, the carbonized AC was subsequently combined with synthesized silver sulphide, resulting in the creation of Ag2S-activated carbon composites that functioned both as adsorbent and photocatalyst. Their capabilities as adsorbents and photocatalyst were studied by using copper ions (Cu2+) and methylene blue (MB) solution. Significance findingsBased on results, GCW and all the prepared activated carbons are in the amorphous phase, except for the Ag2S-AC composites, where the Ag2S peak reflection can be observed from the X-ray diffraction (XRD) pattern. GCW shows rough and dense surface morphology. The AC shows different pore sizes and structures depending on the chemical activators used, where AC-KOH shows the largest pore size (165.31 μm). The existence of micropores can be observed in all the activated carbon samples. For the adsorption of Cu2+, all samples show more than 99 % of the removal efficiency. While for photocatalytic testing, the Ag2S-H3PO4 sample shows the highest degradation rate (97.7 %) of MB solutions.

Development of building benchmarking index for improving gross-floor-area-based energy use intensity

Energy benchmarking is essential for evaluating building performance and developing energy reduction strategies, typically using floor-area-based energy use intensity (EUI). However, this method has limitations. Studies show that metrics such as site energy, source energy, and CO2 emissions can produce varying benchmark results for the same building, raising concerns about reliability. As carbon reduction in buildings becomes increasingly important, there is a need for comprehensive indicators that assess both energy and carbon efficiency. This study introduces the Building Performance Index (BPI), that integrates energy and carbon emission efficiencies. Using a database of all buildings in Seoul, South Korea, we compared five BPI variants: conventional floor-area-based BPI, floor-area-based BPI adjusted for floor area ratio, volume BPI based on floor area, volume BPI adjusted for floor area ratio, and volume BPI based on building footprint. These were evaluated based on six criteria, including model simplicity, sensitivity analysis, data reliability, and indicator stability. While the relative importance of these criteria was not prioritized, this study proposes a shift from traditional two-dimensional metrics to more comprehensive three-dimensional volume-based metrics, offering practical guidance for decision-makers in selecting more reliable benchmarking methods.

Analysis of the Energy and Emission Performance of an Automatic Biomass Boiler in the Context of Efficient Heat Management

Analysis of the Energy and Emission Performance of an Automatic Biomass Boiler in the Context of Efficient Heat Management

Impact of digital trade policy on regional carbon efficiency: a quasi-experimental study in China

Digital trade brings opportunities for the region to develop an open economy, and also leads to changes in regional green productivity and progress towards carbon neutrality. This study uses pilot policies of cross-border e-commerce cities as a quasi-experiment to examine how digital trade policies affect regional carbon emission efficiency. It is found that the carbon efficiency of the pilot cities was significantly improved after the intervention policy of digital trade. This conclusion is still supported by the entropy balance matching sample and the estimator after considering the heterogeneity treatment effect. Digital trade policies can help developing countries improve sustainable competitiveness and pursue carbon neutrality. In addition, digital trade can significantly promote regional energy productivity and green production technology, which is conducive to the improvement of carbon emission efficiency. These findings provide implications and insights for making low-carbon development policies in the era of digital trade.

N-doped three-dimensional carbon nanosheets: Facile synthesis and high-concentration dye adsorption

Purification of dye-contaminated wastewater has always been a research hotspot, yet also a challenge, due to high concentration and species diversity of pollutants. The present study designs an efficient nitrogen-doped 3D carbon nanosheets (N-3DCNs) adsorbent with 2592.50 m2 g−1 of specific surface area and 2.68 m3/g of average pore volume based on nitrilotriacetic acid trisodium salt by combining calcination and activation techniques. Microstructure and surface potential of N-3DCNs indicate that a large number of N heteroatoms in the lattice of main material can effectively optimize Zeta potential from 1.53 to −31.08 mV with solution pH increases from 3 to 11. So, as-prepared N-3DCNs possesses necessary conditions for efficient and selective adsorption of cationic dyes due to the abundant adsorption sites and strong electrostatic interactions. When 700 mg/L of cationic rhodamine and anionic methyl orange are respectively used as high concentration industrial dye-contaminated wastewater, N-3DCNs shows 97.97 % and 89.13 % of removal efficiency within 60 min. Furthermore, the adsorption capacity of N-3DCNs displays a wider pH tolerance at 1000 mg/L of cationic concentration, with a maximum adsorption capacity of 4888.70 mg/g at pH = 7 and a minimum value of 4203.77 mg/g at pH = 3, only 14 % of attenuation rate. The kinetics mechanism of dye adsorption could be well explained by pseudo-second-order kinetic model, suggesting chemisorption behavior, while fitting better with the linear Langmuir isothermal model. The groundbreaking and exceptional adsorption performances of N-3DCNs can be attributed primarily to the high specific surface area and negatively charged active sites, facilitating synergistic adsorption.