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Lithium-ion batteries (LIB) are widely used in various aspects of human life and production due to their safety, convenience, and low cost, especially in the field of electric vehicles (EVs). Currently, the number of LIB worldwide is growing exponentially, which also leads to an increase in discarded LIB. Spent lithium-ion batteries (S-LIB) contain valuable metals and environmentally hazardous chemicals, necessitating proper resource recovery and harmless treatment of these S-LIB. Therefore, research on S-LIB recycling is beneficial for sustainable EVs development. This paper aims to critically review the research progress in the field of S-LIB recycling, focusing on the recycling technology of cathode materials. First, the article introduces the composition, classification, and working principle of LIB. It then discusses the Evaluation and monitoring of batteries that can no longer be used, so that they can be repurposed or dismantled for disposal. Subsequently, introduces that batteries that can no longer be used should undergo Evaluation and monitoring for repurposing or dismantling. Emphasize the treatment of cathode materials, including two traditional recycling methods hydrometallurgy and pyrometallurgy as well as five new direct regeneration technologies and the application of cathode materials in non-battery fields. This work is expected to systematically demonstrate the treatment of S-LIB and is of great significance for the sustainable EVs development of the LIB industry.
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This paper investigates the combustion characteristics and pollutant emission patterns of the mixed combustion of lignite (L) and torrefied pine wood (TPW) under different blending ratios. Isothermal combustion experiments were conducted in a fixed bed reaction system at 800 °C, and pollutant emission concentrations were measured using a flue gas analyzer. Using scanning electron microscopy (SEM) and BET (nitrogen adsorption) experiments, it was found that torrefied pine wood (TPW) has a larger specific surface area and a more developed pore structure, which can facilitate more complete combustion of the sample. The results of the non-isothermal thermogravimetric analysis show that with the TPW blending ratio increase, the entire combustion process advances, and the ignition temperature, maximum peak temperature, and burnout temperature all show a decreasing trend. The kinetic equations of the combustion reaction process of mixed gas were calculated by Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) kinetic equations. The results show that the blending of TPW reduces the activation energy of the combustion reaction of the mixed fuel. When the TPW blending ratio is 80%, the activation energy values of the mixed fuel are the lowest at 111.32 kJ/mol and 104.87 kJ/mol. The abundant alkali metal ions and porous structure in TPW reduce the conversion rates of N and S elements in the fuel to NO and SO2, thus reducing the pollutant emissions from the mixed fuel.
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The conversion of glucose into fructose can transform cellulose into high-value chemicals. This study introduces an innovative synthesis method for creating an MgO-based ordered mesoporous carbon (MgO@OMC) catalyst, aimed at the efficient isomerization of glucose into fructose. Throughout the synthesis process, lignin serves as the exclusive carbon precursor, while Mg2+ functions as both a crosslinking agent and a metallic active center. This enables a one-step synthesis of MgO@OMC via a solvent-induced evaporation self-assembly (EISA) method. The synthesized MgO@OMCs exhibit an impeccable 2D hexagonal ordered mesoporous structure, in addition to a substantial specific surface area (378.2 m2/g) and small MgO nanoparticles (1.52 nm). Furthermore, this catalyst was shown active, selective, and reusable in the isomerization of glucose to fructose. It yields 41 % fructose with a selectivity of up to 89.3 % at a significant glucose loading of 7 wt% in aqueous solution over MgO0.5@OMC-600. This performance closely rivals the current maximum glucose isomerization yield achieved with solid base catalysts. Additionally, the catalyst retains a fructose selectivity above 60 % even after 4 cycles, a feature attributable to its extended ordered mesoporous structure and the spatial confinement effect of the OMCs, bestowing it with high catalytic efficiency.
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Carbono , Fructosa , Glucosa , Lignina , Óxido de Magnesio , Fructosa/química , Lignina/química , Glucosa/química , Carbono/química , Porosidad , Óxido de Magnesio/química , Catálisis , IsomerismoRESUMEN
The discovery of non-precious catalysts for replacing the precious metal of ruthenium in the oxygen evolution reaction (OER) represents a key step in reducing the cost of green hydrogen production. The 2D d-MHOFs, a new 2D materials with controllable oxygen vacancies formed by controlling the degree of coordination bridging between metal hydroxyl oxide and BDC ligands are synthesized at room temperature, exhibit excellent OER properties with low overpotentials of 207 mV at 10 mA cm-2. High-resolution transmission electron microscopy images and density functional theory calculations demonstrate that the introduction of oxygen vacancy sites leads to a lattice distortion and charge redistribution in the catalysts, enhancing the OER activity of 2D d-MHOFs comprehensively. Synchrotron radiation and in situ Raman/Fourier transform infrared spectroscopy indicate that part of oxygen defect sites on the surface of 2D d-MHOFs are prone to transition to highly active metal hydroxyl oxides during the OER process. This work provides a mild strategy for scalable preparation of 2D d-MHOFs nanosheets with controllable oxygen defects, reveals the relationship between oxygen vacancies and OER performance, and offers a profound insight into the basic process of structural transformation in the OER process.
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The cultivation of microalgae and microalgae-bacteria consortia provide a potential efficient strategy to fix CO2 from waste gas, treat wastewater and produce value-added products subsequently. This paper reviews recent developments in CO2 fixation and wastewater treatment by single microalgae, mixed microalgae and microalgae-bacteria consortia, as well as compares and summarizes the differences in utilizing different microorganisms from different aspects. Compared to monoculture of microalgae, a mixed microalgae and microalgae-bacteria consortium may mitigate environmental risk, obtain high biomass, and improve the efficiency of nutrient removal. The applied microalgae include Chlorella sp., Scenedesmus sp., Pediastrum sp., and Phormidium sp. among others, and most strains belong to Chlorophyta and Cyanophyta. The bacteria in microalgae-bacteria consortia are mainly from activated sludge and specific sewage sources. Bioengineer in CBB cycle in microalgae cells provide effective strategy to achieve improvement of CO2 fixation or a high yield of high-value products. The mechanisms of CO2 fixation and nutrient removal by different microbial systems are also explored and concluded, the importance of microalgae in the technology is proven. After cultivation, microalgae biomass can be harvested through physical, chemical, biological and magnetic separation methods and used to produce high-value by-products, such as biofuel, feed, food, biochar, fertilizer, and pharmaceutical bio-compounds. Although this technology has brought many benefits, some challenging obstacles and limitation remain for industrialization and commercializing.
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Ferromanganese spinel oxides (MnFe2O4, MFO) have been proven effective in activating persulfate for pollutants removal. However, their inherent high surface energy often leads to agglomeration, diminishing active sites and consequently restricting catalytic performance. In this study, using Al-MCM-41 (MCM) mesoporous molecular sieves derived from natural attapulgite as a support, the MFO/MCM composite was synthesized through dispersing MnFe2O4 nanoparticles on MCM carrier by a simple hydrothermal method, which can effectively activate persulfate (PS) to degrade Tetracycline (TC). The addition of Al-MCM-41 can effectively improve the specific surface area and adsorption performance of MnFe2O4, but also reduce the leaching amount of metal ions. The MFO/MCM composite exhibited superior catalytic reactivity towards PS and 84.3% removal efficiency and 64.7% mineralization efficiency of TC (20 mg/L) was achieved in 90 min under optimized conditions of 0.05 mg/L catalyst dosage, 5 mM PS concentration, room temperature and no adjustment of initial pH. The effects of various stoichiometric MFO/MCM ratio, catalyst dosage, PS concentration, initial pH value and co-existing ions on the catalytic performance were investigated in detail. Moreover, the possible reaction mechanism in MFO-MCM/PS system was proposed based on the results of quenching tests, electron paramagnetic resonance (EPR) and XPS analyses. Finally, major degradation intermediates of TC were detected by liquid chromatography mass spectrometry technologies (LC-MS) and four possible degradation pathways were proposed. This study enhances the design approach for developing highly efficient, environmentally friendly and low-cost catalysts for the advanced treatment process of antibiotic wastewater.
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Óxido de Aluminio , Hierro , Compuestos de Magnesio , Óxido de Magnesio , Manganeso , Óxidos , Compuestos de Silicona , Dióxido de Silicio , Contaminantes Químicos del Agua , Antibacterianos , Tetraciclina/química , Contaminantes Químicos del Agua/análisisRESUMEN
Shaerhu (SEH) coal is abundant in Xinjiang, China. The utilization of SEH suffers from severe ash deposition, slagging, and fouling problems due to its high-chlorine-alkaline characteristics. The co-combustion of high-alkaline coal and other type coals containing high Si/Al oxides has been proven to be a simple and effective method that will alleviate ash-related problems, but the risk of heavy metals (HMs) contamination in this process is nonnegligible. Hence, the volatilization rates and chemical speciation of Pb, Cu, and Zn in co-combusting SEH and a high Si/Al oxides coal, i.e., Yuanbaoshan (YBS) coal were investigated in this study. The results showed that the addition of SEH increased the volatilization rates of Pb, Cu, and Zn during the co-combustion at 800°C from 23.70%, 23.97%, and 34.98% to 82.31%, 30.01%, and 44.03%, respectively, and promoted the extractable state of Cu and Zn. In addition, the interaction between SEH and YBS inhibited the formation of the Pb residue state. SEM-EDS mapping results showed that compared to Zn and Cu, the signal intensity of Pb was extremely weak in regions where some of the Si and Al signal distributions overlap. The DFT results indicated that the O atoms of the metakaolin (Al2O3â 2SiO2) (001) surface were better bound to the Zn and Cu than Pb atoms after adsorption of the chlorinated HMs. These results contribute to a better understanding of the effects of high-alkaline coal blending combustion on Pb, Cu, and Zn migration and transformation.
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Cloro , Metales Pesados , Cloro/química , Plomo , Incineración , Ceniza del Carbón/química , Carbón Mineral , Metales Pesados/química , Óxidos , ZincRESUMEN
This study explored bagasse's energy potential grown using treated industrial wastewater through various analyses, experimental, kinetic, thermodynamic, and machine learning boosted regression tree methods. Thermogravimetry was employed to determine thermal degradation characteristics, varying the heating rate from 10 to 30 °C/min. The primary pyrolysis products from bagasse are H2, CH4, H2O, CO2, and hydrocarbons. Kinetic parameters were estimated using three model-free methods, yielding activation energies of approximately 245.98 kJ mol-1, 247.58 kJ mol-1, and 244.69 kJ mol-1. Thermodynamic parameters demonstrated the feasibility and reactivity of pyrolysis with ΔH ≈ 240.72 kJ mol-1, ΔG ≈ 162.87 kJ mol-1, and ΔS ≈ 165.35 J mol-1 K-1. The distribution of activation energy was analyzed using the multiple distributed activation energy model. Lastly, boosted regression trees predicted thermal degradation successfully, with an R2 of 0.9943. Therefore, bagasse's potential as an eco-friendly alternative to fossil fuels promotes waste utilization and carbon footprint reduction.
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Celulosa , Pirólisis , Termodinámica , Cinética , TermogravimetríaRESUMEN
Oil spills are sudden, complex, and long-term hazardous, and the existing adsorption materials still have the disadvantages of small selective adsorption capacity, easy secondary contamination, and difficult to repair after breakage in practical applications. Herein, melamine foam (MF) coated by ball milled biochar (BMBC) and natural beeswax (Wax@BMBC@MF) was prepared by a bio-inspired functionalization method and further added with self-healing function (SH-Wax@BMBC@MF) to cope with complex environments, and applied to oil-water separation for oil adsorption. SEM and FTIR results showed that BMBC and natural beeswax nanoparticles successfully encapsulated the smooth surface of the melamine foam skeleton. The loading of natural beeswax increased the foam's ability to absorb oil and organic solvents from 0.6108-1.134 g to 0.850-1.391 g, and the oil-absorbing capacity of the foam remained at 0. 758-1.263 g after being cut by a knife and self-healing. The oil-absorbing capacity of SH-Wax@BMBC@MF remained in the range of 0.936-1.336 g under acid/alkali environment (pH =1-13). The surface functional groups of BMBC improved the surface roughness of the material and strengthen the MF skeleton to adsorb oils and organic solvents by capillary action. The generation of the di-coordinated structure by Fe3+ and catechol group contributed the restoration of SH-Wax@BMBC@MF structure and oil absorption capacity. SH-Wax@BMBC@MF has superiority of superhydrophobic, superoleophilic, self-healing after damage, and environmental friendliness, which provides a promising solution for the treatment of oil spills at sea.
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Volatile organic compounds (VOCs) pose a serious threat to human health and the ecological environment. Thermal catalytic oxidation based on cerium dioxide based (CeO2-based) catalysts is widely used in the degradation of toluene. However, new problems and challenges such as how to reduce the energy consumption during catalytic oxidation, improve the anti-poisoning performance of catalysts, and enhance the multi-species synergistic catalytic ability of catalysts continue to emerge. On this basis, we systematically summarize the current status of research progress on the thermocatalytic oxidation of toluene based on CeO2-based catalysts. Firstly, we summarized the rules on how to improve the catalytic performance and anti-poisoning performance of CeO2-based catalysts; Secondly, we discussed the effect of light reaction conditions on the thermal coupled catalytic oxidation of toluene; In addition to this, we explored the current status of synergistic multi-pollutant degradation, mainly of toluene; Finally, we summarized the mechanism of catalytic oxidation of toluene by combining theoretical simulation calculations, in-situ infrared analyses, and other means. We present the promising applications of CeO2-based catalysts in the catalytic oxidation of toluene, and hope that these summaries will provide an important reference for the catalytic treatment of VOCs.
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Contaminantes Ambientales , Compuestos Orgánicos Volátiles , Humanos , Tolueno/análisis , Oxidación-Reducción , CatálisisRESUMEN
Microplastics (MPs) have emerged as a novel and highly concerning contaminant that is ubiquitous in the aqueous environment. However, the aging of MPs induced by dissolved organic matter (DOM), especially biochar-derived dissolved organic matter (BDOM), and the biological toxicity after aging are not fully understood. In this study, the effects of biochar-derived BDOMs on the photoaging and biotoxicity of MPs were investigated at different pyrolysis temperatures using micro-scale polyethylene (PE) as an example. The results showed that the amount of ·OH generated by the BDOM/PE systems was related to the molecular composition and structure of BDOMs. High temperature BDOM7/9 with less lignin-like (34.33 % / 41.80 %) and more lipid (24.58 % / 19.88 %) content could produce more ·OH by itself, and its binding ability with PE was weaker due to its less hydrophobic components (SUVA260 = 0.10 / 0.11), which resulted in a weaker shading effect and less inhibition of the system, thus resulting in more ·OH production in the high temperature BDOM7/9/PE system. However, the involvement of BDOM, although favoring the long-term stable ·OH production of the system, did not significantly promote the photoaging of MPs. Furthermore, combined in vivo and in vitro biotoxicity studies of MPs showed that photoaging PE with the involvement of BDOM greatly improved systemic inflammation and tissue damage, as well as reactive oxygen species (ROS, such as ·OH and -OH)-induced cell death. For example, the addition of BDOM5/PE-light reduced the cell death of human lung, liver, and kidney cells from 54.70 %, 69.39 %, and 48.35 % to 22.78 %, 33.13 %, and 25.83 %, respectively, compared to the PE-light group. The results of this study contribute to an in-depth understanding of the environmental behavior of BDOM and MPs systems.
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Carbón Orgánico , Materia Orgánica Disuelta , Microplásticos , Humanos , Microplásticos/toxicidad , Plásticos , Temperatura , Pirólisis , Polietileno , EnvejecimientoRESUMEN
Pyrolysis and activation processes are important pathways to utilize residues after lipid extraction from microalgae in a high-value way. The obtained microalgae-based nitrogen-doped activated carbon has excellent electrochemical performance. It has the advantage of nitrogen self-doping using high elemental nitrogen in microalgae. In this study, two kinds of microalgae, Nanochloropsis and Chlorella, were used as feedstock for lipid extraction. The microalgae residue was firstly pyrolyzed at 500 °C to obtain biochar. Then, nitrogen-doped activated carbons were synthesized at an activation temperature of 700-900 °C with different ratios of biochar and KOH (1:1, 1:2, and 1:4). The obtained carbon materials presented rich nitrogen functional groups, including quaternary-N, pyridine-N-oxide, pyrrolic-N, and pyridinic-N. The nitrogen content of microalgae-based activated carbon material was up to 2.62%. The obtained materials had a specific surface area of up to 3186 m2/g and a pore volume in the range of 0.78-1.54 cm3/g. The microporous pore sizes of these materials were distributed at around 0.4 nm. Through electrochemical testing such as cyclic voltammetry and galvanostatic charge-discharge of materials, the materials exhibited good reversibility and high charge-discharge efficiency. The sample, sourced from microalgae Chlorella residue at activation conditions of 700 °C and biochar/KOH = 1:4, exhibited excellent endurance of 94.1% over 5000 cycles at 2 A/g. Its high specific capacitance was 432 F/g at 1 A/g.
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Chlorella , Microalgas , Carbón Orgánico , Nitrógeno/química , Pirólisis , LípidosRESUMEN
Chlorella vulgaris (C. vulgaris) can provide the means to fix CO2 from complicated flue gas, treat wastewater and reach a sustainable production of petrochemical substitutes simultaneously. However, a prerequisite to achieving this goal is to promote C. vulgaris growth and improve the CO2-to-fatty acids conversion efficiency under different conditions of flue gas and wastewater. Thus, the addition of indole-3-acetic acid (IAA) in C. vulgaris cultivation was proposed. Results showed that C. vulgaris were more easily inhibited by 100 ppm NO and 200 ppm SO2 under low nitrogen (N) condition. NO and SO2 decreased the carbon (C) fixation; but increased N and sulfur (S) fixation. IAA adjusted the content of superoxide dismutase (SOD) and malondialdehyde (MDA), improved the expression of psbA, rbcL, and accD, attenuated the toxicity of NO and SO2 on C. vulgaris, and ultimately improved cell growth (2014.64-2458.16 mgdw·L-1) and restored CO2 fixation rate (170.98-220.92 mg CO2·L-1·d-1). Moreover, wastewater was found to have a high treatment efficiency because C. vulgaris grew well in all treatments, and the maximal removal rates of both N and phosphorus (P) reached 100%. Metabonomic analysis showed that IAA, "NO and SO2" were involved in the down-regulated and up-regulated expression of multiple metabolites, such as fatty acids, amino acids, and carbohydrates. IAA was beneficial for improving lipid accumulation with 24584.21-27634.23 µg g-1, especially monounsaturated fatty acids (MUFAs) dominated by 16-18 C fatty acids, in C. vulgaris cells. It was concluded that IAA enhanced the CO2 fixation, fatty acids production of C. vulgaris and its nutrients removal rate.
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Chlorella vulgaris , Microalgas , Purificación del Agua , Chlorella vulgaris/metabolismo , Aguas Residuales , Lípidos , Reguladores del Crecimiento de las Plantas/metabolismo , Dióxido de Carbono/metabolismo , Ácidos Grasos/metabolismo , Metaboloma , Biomasa , Microalgas/metabolismoRESUMEN
To promote the practical application of TiO2 in photocatalytic toluene oxidation, the honeycomb aluminum plates were selected as the metal substrate for the loading of TiO2 powder. Surface-etching treatment was performed and titanium tetrachloride was selected as the binder to strengthen the loading stability. The loading stability and photocatalytic activity of the monolithic catalyst were further investigated, and the optimal surface treatment scheme (acid etching with 15.0 wt.% HNO3 solution for 15 min impregnation) was proposed. Therein, the optimal monolithic catalyst could achieve the loading efficiency of 42.4% and toluene degradation efficiencies of 76.2%. The mechanism for the stable loading of TiO2 was revealed by experiment and DFT calculation. The high surface roughness of metal substrate and the strong chemisorption between TiO2 and TiCl4 accounted for the high loading efficiency and photocatalytic activity. This work provides the pioneering exploration for the practical application of TiO2 catalysts loaded on the surface of metal substrate for VOCs removal, which is of significance for the large-scaled application of photocatalytic technology.
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Energy crises and environmental degradation are serious in recent years. Inexhaustible solar energy can be used for photocatalytic hydrogen production or CO2 reduction to reduce CO2 emissions. At present, the development of efficient photocatalysts is imminent. MXene as new two-dimensional (2D) layered material, has been used in various fields in recent years. Based on its high conductivity, adjustable band gap structure and sizable specific surface area, the MXene is beneficial to hasten the separation and reduce the combination of photoelectron-hole pairs in photocatalysis. Nevertheless, the re-stacking of layers because of the strong van der Waals force and hydrogen bonding interactions seriously hinder the development of MXene material as photocatalysts. By contrast, the MXene-based heterostructures composed of MXene nanosheets and other materials not only effectively suppress the re-stacking of layers, but also show the superior synergistic effects in photocatalysis. Herein, the recent progress of the MXene-based heterostructures as photocatalysts in energy and environment fields is summarized in this review. Particularly, new synthetic strategies, morphologies, structures, and mechanisms of MXene-based heterostructures are highlighted in hydrogen production, CO2 reduction, and pollutant degradation. In addition, the structure-activity relationship between the synthesis strategy, components, morphology and structure of MXene-based heterostructures, and their photocatalytic properties are elaborated in detail. Finally, a summary and the perspectives on improving the application study of the heterostructures in photocatalysis are presented.
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Dióxido de Carbono , Contaminantes Ambientales , Conductividad Eléctrica , HidrógenoRESUMEN
Developing new photocatalysts to achieve efficient removal of phthalate esters (PAEs) in water is an important research task in environmental science. However, existing modification strategies for photocatalysts often focus on enhancing the efficiency of material photogenerated charge separation, neglecting the degradation characteristics of PAEs. In this work, we proposed an effective strategy for the photodegradation process of PAEs: introducing vacancy pair defects. We developed a BiOBr photocatalyst containing "Bi-Br" vacancy pairs, and confirmed that it has an excellent photocatalytic activity in removing phthalate esters (PAEs). Through a combination of experimental and theoretical calculations, it is proved that "Bi-Br" vacancy pairs can not only improve the charge separation efficiency, but also alter the adsorption configuration of O2, thus accelerating the formation and transformation of reactive oxygen species. Moreover, "Bi-Br" vacancy pairs can effectively improve the adsorption and activation of PAEs on the surface of samples, surpassing the effect of O vacancies. This work enriches the design concept of constructing highly active photocatalysts based on defect engineering, and provides a new idea for the treatment of PAEs in water.
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Wheat straw, a typical agricultural solid waste, was employed to clarify the effects of torrefaction on the structural features and combustion reactivity of biomass. Two typical torrefaction temperatures (543 K and 573 K), four atmospheres (argon, 6 vol.% O2, dry flue gas and raw flue gas) were selected. The elemental distribution, compositional variation, surface physicochemical structure and combustion reactivity of each sample were identified using elemental analysis, XPS, N2 adsorption, TGA and FOW methods. Oxidative torrefaction tended to optimize the fuel quality of biomass effectively, and the enhancement of torrefaction severity improved the fuel quality of wheat straw. The O2, CO2 and H2O in flue gas could synergistically enhance the desorption of hydrophilic structures during oxidative torrefaction process, especially at high temperatures. Meanwhile, the variations in microstructure of wheat straw promoted the conversion of N-A into edge nitrogen structures (N-5 and N-6), especially N-5, which is a precursor of HCN. Additionally, mild surface oxidation tended to promote the generation of some new oxygen-containing functionalities with high reactivity on the surface of wheat straw particles after undergoing oxidative torrefaction pretreatment. Due to the removal of hemicellulose and cellulose from wheat straw particles and the generation of new functional groups on the particle surfaces, the ignition temperature of each torrefied sample expressed an increasing tendency, while the Ea clearly decreased. According to the results obtained from this research, it could be concluded that torrefaction conducted in a raw flue gas atmosphere at 573 K would improve the fuel quality and reactivity of wheat straw most significantly.
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Energy storage devices require separators with sufficient lithium-ion transfer and restrained lithium dendrite growth. Herein, PMIA separators tuned using MIL-101(Cr) (PMIA/MIL-101) were designed and fabricated by a one-step casting process. At 150 °C, the Cr3+ in the MIL-101(Cr) framework sheds two water molecules to form an active metal site that complexes with PF6- in the electrolyte on the solid/liquid interface, leading to improved Li+ transport. The Li+ transference number of the PMIA/MIL-101 composite separator was found to be 0.65, which is about 3 times higher than that of the pure PMIA separator (0.23). Additionally, MIL-101(Cr) can modulate the pore size and porosity of the PMIA separator, while its porous structure also functions as additional storage space for the electrolyte, enhancing the electrochemical performance of the PMIA separator. After 50 charge/discharge cycles, batteries assembled using the PMIA/MIL-101 composite separator and the PMIA separator presented a discharge specific capacity of 120.4 and 108.6 mAh/g, respectively. The battery assembled using PMIA/MIL-101 composite separator significantly outperformed both the batteries assembled from pure PMIA and commercial PP separators in terms of cycling performance at 2 C, displaying a discharge specific capacity of 1.5 times that of the battery assembled from PP separators. The chemical complexation of Cr3+ and PF6- plays a critical role to improve the electrochemical performance of the PMIA/MIL-101 composite separator. The tunability and enhanced properties of the PMIA/MIL-101 composite separator make it a promising candidate for use in energy storage devices.
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This study was to develop a low-cost N-doped porous biocarbon adsorbent that can directly adsorb CO2 in high-temperature flue gas from fossil fuel combustion. The porous biocarbon was prepared by nitrogen doping and nitrogen-oxygen codoping through K2CO3 activation. Results showed that these samples exhibited a high specific surface area of 1209-2307 m2/g with a pore volume of 0.492-0.868 cm3/g and a nitrogen content of 0.41-3.3 wt %. The optimized sample CNNK-1 exhibited a high adsorption capacity of 1.30 and 0.27 mmol/g in the simulated flue gas (14.4 vol % CO2 + 85.6 vol % N2) and a high CO2/N2 selectivity of 80 and 20 at 25 and 100 °C and 1 bar, respectively. Studies revealed that too many microporous pores could hinder CO2 diffusion and adsorption due to the decrease of CO2 partial pressure and thermodynamic driving force in the simulated flue gas. The CO2 adsorption of the samples was mainly chemical adsorption at 100 °C, which depended on the surface nitrogen functional groups. Nitrogen functional groups (pyridinic-N and primary and secondary amines) reacted chemically with CO2 to produce graphitic-N, pyrrolic-like structures, and carboxyl functional groups (-N-COOH). Nitrogen and oxygen codoping increased the amount of nitrogen doping content in the sample, but acidic oxygen functional groups (carboxyl groups, lactones, and phenols) were introduced, which weakened the acid-base interactions between the sample and CO2 molecules. It was demonstrated that SO2 and water vapor had inhibition effects on CO2 adsorption, while NO nearly has no effect on the complex flue gas. Cyclic regenerative adsorption showed that CNNK-1 possessed excellent regeneration and stabilization ability in complex flue gases, indicating that corncob-derived biocarbon had excellent CO2 adsorption in high-temperature flue gas.
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Photocatalytic oxidation technology holds promise for ideal advanced treatment of antibiotic wastewater. Single-atom catalysts (SACs) are a new hotspot in catalytic science, but the photochemical studies on the removal of antibiotics from water and biocompatibility after entering the environment are scarce. In this work, we prepared a single Mn atom immobilized on N-doped biochar (Mn@N-Biochar) by impregnation calcination method for enhancing photocatalytic degradation of sulfanilamide (SNM) in different types of various water systems. Compared with the original biochar, Mn@N-Biochar showed enhanced SNM degradation and TOC removal capacity. DFT calculation concluded that the electrons of d-orbital (Mn) and p-orbital (N) altered the electronic structure of biochar and enhanced the photoelectric performance. It was shown that Mn@N-Biochar caused negligible systemic inflammation and tissue damage when given orally in mice, and also did not alter cell death and ROS production in human lung, kidney, and liver cells, as compared with biochar. We are convinced that Mn@N-Biochar could enhance the photocatalytic degradation of antibiotics while maintaining biocompatibility, which could be a promising strategy for wastewater treatment.