Regeneration Performance Research Articles

Examining collaborative planning processes and outcomes in urban regeneration: A deliberative turn in China?

Collaborative planning practices have recently emerged in China to deal with the complexity and conflicts of interest in urban regeneration. Building on the concept of authoritarian deliberation, this study develops a conceptual framework to examine the reasons for initiating collaborative planning, and its processes and outcomes. Through the case study of Guangzhou’s Enning Road micro-regeneration project, this research deepens understanding of collaborative planning in an authoritarian context. It reveals that deliberative methods were used by the local government to mitigate conflicts and improve governance performance in urban regeneration. While deliberations in an authoritarian context met many process criteria of collaborative planning, the collaborative processes had limited influence on planning outcomes. In addition, this study marks the increased level of participation in Chinese urban regeneration and discusses the limitation of deliberative practices in an authoritarian context. Lastly, this study reflects on the adoption of collaborative planning approaches as a state strategy to balance various interests and reinforce its dominance in market-driven urban regeneration, ultimately to achieve goals beyond economic benefits.

Preparation and Selective Adsorption Performance of the Carboxymethyl Salix psammophila Wood Powder-Imprinted Membrane for Tetracycline.

Carboxymethyl Salix psammophila wood powder-imprinted membranes (CMSM-MIPs) were prepared by using wet spinning technology and molecular-imprinting technology for the selective removal of tetracycline from wastewater. Scanning electron microscopy, X-ray diffraction, thermogravimetry, and X-ray photoelectron spectroscopy characterizations demonstrate that CMSM-MIPs retain the membranous structure of Carboxymethyl Salix psammophila wood powder membranes, successfully encapsulate thin layers of imprinted polymers on the membrane surface, and exhibit excellent thermal stability. The adsorption results showed that CMSM-MIPs had the highest selective adsorption capacity for tetracycline, which was 253.8 mg/g. In addition, the adsorption capacities for oxytetracycline and chlortetracycline were 208.8 and 188 mg/g, respectively. It can be observed that CMSM-MIPs not only exhibit a high adsorption capacity for tetracycline but also demonstrate good adsorption capacities for oxytetracycline and chlortetracycline. The experimental results showed that CMSM-MIPs were best fitted with pseudo-second-order kinetics and most consistent with Freundlich fitting. The regeneration experiment showed that CMSM-MIPs still had good regeneration performance after 5 regeneration cycles. In conclusion, the CMSM-MIPs can not only have the natural adsorption performance of Salix psammophila wood powder but also give it higher selectivity through molecular imprinting, so as to achieve efficient removal of target organic pollutants in water.

Superparamagnetic hydrophilic molecularly imprinted nanoparticles for an efficient and selective removal of tetracycline from water

In this work, a novel superparamagnetic hydrophilic molecularly imprinted nanomaterial for the removal of tetracycline (TC) was synthesized utilizing magnetite (Fe3O4) as the magnetic core, TC as the template molecule, 3-aminopropyltriethoxysilane (APTES) as the functional monomer, and tetraethoxysilane (TEOS) as the cross-linker. Initially, Fe3O4 magnetic nanoparticles (MNP) coated with SiO2 (MNP@SiO2) were synthesized, followed by TC molecular imprinting on the nanoparticles. Initially, Fe3O4 MNP coated with SiO2 (MNP@SiO2) were synthesized, followed by TC molecular imprinting on the nanoparticles. The synthesis method for MNP@SiO2 was optimized, and DLS analysis of 10 replicates showed a nanoparticle size of 70.1 ± 5.8 nm, indicating high method reproducibility. The MNP@SiO2, as well as the imprinted (MNP@SiO2-MIP) and non-imprinted (MNP@SiO2–NIP) nanomaterials, were characterized by FTIR, TEM, VSM, XRD, DLS, Z potential, and BET analysis. The saturation magnetization (Ms) values were 43 emu/g for MNP@SiO2 and 32 emu/g for both MNP@SiO2-MIP and MNP@SiO2–NIP, confirming suitability for magnetic separation using external magnets. Batch binding experiments conducted in water and methanol assessed adsorption isotherms and binding kinetics, with data fitting the Langmuir isotherm model better than the Freundlich model. The developed MIP exhibited significant selectivity against other molecules with similar functional groups and size. In water, the adsorption capacity of the MNP@SiO2-MIP was 23 mg/g, with an imprinting factor of 2.2. Furthermore, the MIP demonstrated good regeneration performance. The material was tested on TC-spiked tap water samples, achieving 80.1 % TC removal with high reproducibility (3.2 %, n = 3). Combining hydrophilic superparamagnetic nanoparticles with molecular imprinting enhances their potential applications in environmental remediation, antibiotic purification, and drug delivery.

Mechanical Properties and Microscopic Study of Recycled Fibre Concrete Based on Wind Turbine Blades.

In recent years, wind energy has begun to receive a significant amount of attention as clean energy is utilised and demanded in large quantities, resulting in a sharp increase in the use of wind turbines. The demand for wind turbines has gradually risen due to the clean and recyclable nature of wind energy. The current blade life of wind turbines in China is about 20 years, which means that the disposal of obsolete used blades can become a difficult problem in the future. Therefore, this study is of great significance to explore the regeneration performance of the blades after recycling and disposal. In this paper, wind turbine blades were mechanically recycled into recycled macrofibres, which were added to concrete as a reinforcing material to make wind impeller fibre concrete (WIC), and the three proportion ratios of 1%, 1.5%, and 2% were explored to compare the performance. The performance of WIC was also evaluated and its performance was compared to that of glass fibre concrete (GC). In addition, the material physical properties of second-generation recycled aggregate concrete (RAC) based on WIC were explored. The strength and peak strain variations and their causal mechanisms were analysed both macroscopically and microscopically by means of the classical mechanical tests (compression and bending tests), SEM, and XRD. The results show that the compressive strength of WIC was negatively correlated with the fibre content and increased by 6.04-18.12% compared to that of ordinary concrete (OG), with a maximum of 19.25 MPa; the flexural strength was positively correlated with the fibre content, with an increase of 5.37-18.5%. The microstructural analysis confirmed the macroscopic results and the intrinsic model better validated the experimental results.

Hydrogel-chitosan and polylactic acid-polycaprolactone bioengineered scaffolds for reconstruction of mandibular defects: a preclinical in vivo study with assessment of translationally relevant aspects.

Background: Reconstruction of mandibular bone defects is a surgical challenge, and microvascular reconstruction is the current gold standard. The field of tissue bioengineering has been providing an increasing number of alternative strategies for bone reconstruction. Methods: In this preclinical study, the performance of two bioengineered scaffolds, a hydrogel made of polyethylene glycol-chitosan (HyCh) and a hybrid core-shell combination of poly (L-lactic acid)/poly ( -caprolactone) and HyCh (PLA-PCL-HyCh), seeded with different concentrations of human mesenchymal stromal cells (hMSCs), has been explored in non-critical size mandibular defects in a rabbit model. The bone regenerative properties of the bioengineered scaffolds were analyzed by in vivo radiological examinations and ex vivo radiological, histomorphological, and immunohistochemical analyses. Results: The relative density increase (RDI) was significantly more pronounced in defects where a scaffold was placed, particularly if seeded with hMSCs. The immunohistochemical profile showed significantly higher expression of both VEGF-A and osteopontin in defects reconstructed with scaffolds. Native microarchitectural characteristics were not demonstrated in any experimental group. Conclusion: Herein, we demonstrate that bone regeneration can be boosted by scaffold- and seeded scaffold-reconstruction, achieving, respectively, 50% and 70% restoration of presurgical bone density in 120days, compared to 40% restoration seen in spontaneous regeneration. Although optimization of the regenerative performance is needed, these results will help to establish a baseline reference for future experiments.

Adsorption mechanism and electrochemical properties of disperse blue 2BLN onto magnetic Cu0.2Zn0.3Co0.5Fe2O4 nanoparticles prepared via the rapid combustion process

AbstractMagnetic Cu0.2Zn0.3Co0.5Fe2O4 nanoparticles were prepared by the rapid combustion method and characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), x‐ray diffraction (XRD), and vibrating sample magnetometer (VSM). The average particle size and the saturation magnetization of the nanoparticles prepared at 400°C with 25 mL absolute alcohol were about 60.9 nm and 50 emu/g. The results of the experiment displayed that the adsorption process agreed with the pseudo‐second‐order kinetics model (R2 > 0.98) and Langmuir isotherm model (R2 = 0.9982), indicating that the adsorption of DB‐2BLN onto magnetic Cu0.2Zn0.3Co0.5Fe2O4 nanoparticles was monolayer chemisorption. ΔH (ΔH = −28.0135 kJ/mol) of the thermodynamic experiment was less than 0, indicating that the adsorption was an exothermic process. The effects of pH, initial concentration of dye, ionic strength, temperature, and adsorbent dosage on the adsorption process of DB‐2BLN onto magnetic Cu0.2Zn0.3Co0.5Fe2O4 nanoparticles and the regeneration performance of the nanoparticles were investigated. When the pH was determined to be 2 and the adsorbent dosage was 5 mg, the adsorption capacity reached the maximum. After 7 cycles, the removal rate of DB‐2BLN still reached 92.6% of that for the first adsorption, showing excellent regeneration performance. Finally, the electrochemical properties of the magnetic Cu0.2Zn0.3Co0.5Fe2O4 nanoparticles were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).

Alcohol-alcohol-based draw solute minimizes the reverse solute flux in forward osmosis desalination.

Recently, alcohol-based draw solute (DS), i.e., alcohol with water, is one of the trending research topics in forward osmosis (FO) because of its performance and ease of regeneration. Nevertheless, the higher reverse solute flux (RSF) of the alcohol-based DS hinders its commercialization in water and wastewater treatment applications. This research aims to minimize the RSF of the alcohol-based DS in FO by investigating the possibility of using alcohol-alcohol-based draw solutes for the first time. Three alcohol-alcohol-based draw solutions, namely, (1) E70 + IPA30 (ethanol: 70% + isopropanol: 30%), (2) E40 + IPA60 (ethanol: 40% + isopropanol: 60%), and (3) E10 + IPA90 (ethanol: 10% + isopropanol: 90%), were prepared and the properties (including osmolality, shear stress, and viscosity) of the DS were first investigated followed by the parametric investigation (concerning temperature and concentration). The results were further analyzed with the fixed-point iterative method in MATLAB to obtain the performance parameters. Results reveal that the E10 + IPA90 mixture yields a lower RSF of 40.62g/m2/h and specific reverse solute flux of3.78g/L with a considerably good water flux and recovery percentage of 11.47 LMH and 26.29%, respectively, as compared to other DS E70 + IPA30 and E40 + IPA60 at 25°C. Thus, E10 + IPA90 is recommended as a potential candidate to be used as a DS in FO.

Photoregenerable nanoadsorbents with macromolecular brushes for the clearance of bilirubin in serum

The ultrahigh concentration of bilirubin (BR) is recognized as a key factor leading to biliary cirrhosis and irreversible brain damage, with the efficient removal of BR from blood being an effective therapy against these conditions. However, the practical application of adsorbents for blood purification is often compromised by their poor regenerative performance. Therefore, by leveraging the excellent structure-function properties of stimuli-responsive materials, we developed photoregenerable nanoadsorbents (SiO2@MAzoPy–x) with excellent cyclic removal performance. We employed azobenzene macromolecule brushes as the functional ligand to enhance the adsorption performance of the nanoadsorbents and enable efficient regeneration. The best-performing nanoadsorbent exhibited BR adsorption rates of 69.71 % and 65.20 % in phosphate-buffered saline (PBS) and simulated plasma, respectively, and showed superior adsorption efficiency in patients’ serum compared to the unmodified SiO2 (≤ 5.4 %). The binding mechanism suggested that BR and the nanoadsorbent interacted through hydrophobic and electrostatic forces. Importantly, the nanoadsorbents could be photoregenerated with a recovery rate of 99 % in PBS after five regeneration experiments using a green process. Owing to their superior photoregenerative properties, the proposed nanoadsorbents show promise for clinical application.

One pot synthesis of novel C3N4/C nanosheet composites under environmental benign molten salts for peroxymonosulfate activation with enhanced efficiency and reusability

The application of g-C3N4 based carbon materials in peroxymonosulfate (PMS) activation has faced challenges due to the electrochemically inert nature of nitrogen without light irradiation. In this study, two types of crystalline C3N4/C nanosheet composite catalysts were synthesized from glucose and dicyandiamide (DCD) via molten salt-assisted pyrolysis, denoted as M-GD and M-GD2. Both the composite catalysts showed significant improvement in the degradation of acid orange 7 amid PMS activation, taking the advantages of high graphitic N content and defect degree. Specifically, M-GD2 with excessive dosage of DCD exhibited a record catalyst specific activity value (0.0925 L min−1 m−2) in comparison with conventional C3N4 based carbon catalysts. The study also examined the effects of catalyst and PMS concentrations, temperatures, initial pH, and impurity ions on catalytic activity, as well as the catalytic performance in actual sludge wastewater cases. Notably, the M-GD2 catalyst exhibited exceptional regeneration capacity after four consecutive tests, attributed to its unique 3D structure comprising g-C3N4 nanoparticles loaded on crystalline C3N4/C nanosheets. Mechanism analysis revealed that a non-radical mechanism predominantly drove the PMS activation reaction, primarily involving catalyst-mediated electron transfer and surface-bound radicals due to the formation of catalyst-PMS* complexes. This work presents a facile and economical method for preparing defect-rich crystalline C3N4/C nanosheet composite with high graphitic N content, highlighting its catalytic activity, reusability, and regeneration performance synchronously. These findings contribute to advancing the field of PMS activation and offer promising applications in water environment remediation.

K+ promoted fabrication of nanoneedle low-silicon ZSM-48 mesocrystal

Owing to their distinct structural properties, low-dimensional zeolites are rising stars in the field of catalysis. However, shortening their size while maintaining the acidity continues to be challenging. In addition, simplified synthesis methods to efficiently prepare low-dimensional zeolites with more skeleton types and extended frame components are also of great interest. Herein, a facile strategy is developed for fabricating ultrathin nanoneedle (ca. 6-8 nm in diameter of each needle) ZSM-48 mesocrystals with a low Si/Al ratio (ca. 27, close to the lowest synthesized so far). This is achieved by adding potassium ions in a ZSM-12 synthetic system. The promoting effect of appropriate K+ ions was confirmed by adjusting the gel composition and tracking the crystallization process. Moreover, a superior conversion, reusability and regeneration performance for xylose to furfural is achieved with more accessible acidity and a more suitable Lewis/Brønsted acid ratio, which further expands the development of ZSM-48 zeolite.

Research on the Preparation and Performance of Biomimetic Warm-Mix Regeneration for Asphalt Mixtures

To determine the formula for biomimetic warm-mix regeneration and fulfill the requirements of a “high waste asphalt mixture content, high quality, and high level” for its usage in reclaimed asphalt pavement (RAP), this paper first determined the suitable preparation process and formula for biomimetic warm-mix regeneration based on orthogonal experiments and a gray correlation analysis. Then, the optimum dosage of the warm-mix regenerant was determined by a uniaxial penetration test, low-temperature splitting test, and freeze–thaw penetration test. The rutting test was conducted to characterize the high-temperature performance of the asphalt mixture. The Immersion Marshall Test and the freeze–thaw splitting test were used to characterize the water stability of the recycled asphalt mixture. The low-temperature small beam test was employed to study the low-temperature performance of the recycled asphalt mixture. The asphalt’s short-term and long-term aging processes were simulated using the rotary thin-film oven test (RTFOT) and the pressure aging test (PAV). The action mechanism of biomimetic warm-mix regeneration was revealed by Fourier-transform infrared spectroscopy (FTIR). Finally, a comprehensive thermal performance test was conducted on the aged asphalt after biomimetic warm-mix regeneration. The results showed that the self-made biomimetic warm-mix regeneration agent exhibited an excellent regenerative effect on RAP and significantly reduced the mixing temperature of the styrene–butadiene–styrene (SBS)-modified asphalt mixture. In addition, the self-made biomimetic warm-mix regeneration agent effectively improved the high- and low-temperature performance of the recycled asphalt mixture, but had no noticeable effect on the water stability. The suggested dosage of the biomimetic warm-mix regeneration agent was 6%, and the mixing temperature was 130 °C. The microscopic chemical analysis revealed that biomimetic warm-mix regeneration restored the performance of aged asphalt by supplementing the light component. The change rules of the chemical functional groups and the comprehensive thermal properties of the recycled mixture showed a good correlation with the change rules of its high- and low-temperature performance.

Chitosan-based high-performance flexible supercapacitor via “in-situ co-doping/self-regulation-activation” strategy

The construction of N, P co-doped hierarchically porous carbons (NPHPC) by a facile and green approach is crucial for high-performance energy storage but still an enormous challenge. Herein, an environment-friendly “in-situ co-doping, self-regulation-activation” strategy is presented to one-pot synthesize NPHPC using a phytic acid-induced polyethyleneimine/chitosan gel (PEI-PA-CS) as single precursor. NPHPC displayed a specific surface area of up to 1494 m2 g−1, high specific capacitance of 449 F g−1 at 1 A g−1, outstanding rate capability and cycling durability in a wide temperature range (−20 to 60 °C). NPHPC and PEI-PA-CS electrolyte assembled symmetric quasi-solid-state flexible supercapacitor presents superb energy outputs of 27.06 Wh kg−1 at power density of 225 W kg−1. For capacitive deionization (CDI), NPHPC also exhibit an excellent salt adsorption capacity of 16.54 mg g−1 in 500 mg L−1 NaCl solution at a voltage of 1.4 V, and regeneration performance. This study provides a valuable reference for the rational design and synthesis of novel biomass-derived energy-storage materials by integrating phytic acid induced heteroatom doping and pore engineering.

MgSiO3 Fiber Membrane Scaffold with Triggered Drug Delivery for Osteosarcoma Synergetic Therapy and Bone Regeneration.

In this research, a novel MgSiO3 fiber membrane (MSFM) loaded with indocyanine green (ICG) and doxorubicin (DOX) was prepared. Because of MgSiO3's unique lamellar structure composed of a silicon-oxygen tetrahedron, magnesium ion (Mg2+) moves easily and can be further replaced with other cations. Therefore, because of the positively charged functional group of ICG, MSFM has a rather high drug loading for ICG. In addition, there is electrostatic attraction between DOX (a cationic drug) and ICG (an anionic drug). Hence, after loading ICG, more DOX can be adsorbed into MSFM because of electrostatic interaction. The ICG endows the MSFM outstanding photothermal therapy (PTT) performance, and DOX as a chemotherapeutic drug can restrain tumor growth. On the one hand, H+ exchanged with the positively charged DOX based on the MgSiO3 special lamellar structure. On the other hand, the thermal effect could break the electrostatic interaction between ICG and DOX. Based on the above two points, both tumor acidic microenvironment and photothermal effect can trigger DOX release. What's more, in vitro and in vivo antiosteosarcoma therapy evaluations displayed a superior synergetic PTT-chemotherapy anticancer treatment and excellent biocompatibility of DOX&ICG-MSFM. Finally, the MSFM was proven to greatly promote cell proliferation, differentiation, and bone regeneration performance in vitro and in vivo. Therefore, MSFM provides a creative perspective in the design of multifunctional scaffolds and shows promising applications in controlled drug delivery, antitumor performance, and osteogenesis.

Research on environmentally friendly regeneration of adsorbents for SF6 gas-insulated equipment based on dielectric barrier discharge

This study evaluates the effectiveness of Dielectric Barrier Discharge (DBD) technology in regenerating adsorbents from decommissioned SF6 equipment, aiming to provide an efficient method for such treatments. The experimental platform constructed for this purpose explores the impact of power supply frequency, input power, carrier gas flow rate, and treatment time on the regeneration performance. The adsorbent's optimal treatment outcomes were observed at the center frequency, showcasing rapid changes in regeneration rate and pH. Furthermore, increasing the carrier gas flow rate enhanced the regeneration rate, with the fastest recovery observed at 0.6 L/min, given constant power conditions. Characterization analyses using XPS, FTIR, XRD, and N2 adsorption-desorption tests indicated a reduction in F and S element compounds, confirming the efficacy of DBD. When compared to traditional thermal regeneration methods, DBD technology offers a more effective and structure-preserving solution for treating adsorbents from decommissioned SF6 equipment.

Methacrylated Carboxymethyl Chitosan Scaffold Containing Icariin-Loaded Short Fibers for Antibacterial, Hemostasis, and Bone Regeneration.

Bone defects typically result in bone nonunion, delayed or nonhealing, and localized dysfunction, and commonly used clinical treatments (i.e., autologous and allogeneic grafts) have limited results. The multifunctional bone tissue engineering scaffold provides a new treatment for the repair of bone defects. Herein, a three-dimensional porous composite scaffold with stable mechanical support, effective antibacterial and hemostasis properties, and the ability to promote the rapid repair of bone defects was synthesized using methacrylated carboxymethyl chitosan and icariin-loaded poly-l-lactide/gelatin short fibers (M-CMCS-SFs). Icariin-loaded SFs in the M-CMCS scaffold resulted in the sustained release of osteogenic agents, which was beneficial for mechanical reinforcement. Both the porous structure and the use of chitosan facilitate the effective absorption of blood and fluid exudates. Moreover, its superior antibacterial properties could prevent the occurrence of inflammation and infection. When cultured with bone mesenchymal stem cells, the composite scaffold showed a promotion in osteogenic differentiation. Taken together, such a multifunctional composite scaffold showed comprehensive performance in antibacterial, hemostasis, and bone regeneration, thus holding promising potential in the repair of bone defects and related medical treatments.

Study on Desulfurization and Regeneration Performance of Nanofluid System Based on Heteropoly Compound/Ionic Liquid Solutions

Study on Desulfurization and Regeneration Performance of Nanofluid System Based on Heteropoly Compound/Ionic Liquid Solutions

Facile construction of pH-responsive graphene oxide-based aerogel and its efficient and selective adsorption performance toward methylene blue

In regard to serious environmental pollution by methylene blue (MB) dye, it was crucial to design an efficacious adsorbent for the elimination of MB. Utilizing tannic acid (TA) to functionalize graphene oxide (GO) and employing acrylic acid (AA) and sodium p-styrenesulfonate (SSS) as the monomers, a pH-responsive TGO/P(SSS-co-AA) aerogel (where TGO represented TA-modified GO, and P(SSS-co-AA) denoted the copolymer of SSS and AA) was synthesized by a facile and green one-pot method. The resulting aerogel was subjected to a variety of characterizations, and its adsorption behaviors were systematically explored with MB as the model dye. The results indicated the pH-responsive TGO/P(SSS-co-AA) aerogel possessed the maximum theoretical adsorption capacity of 1782.5 mg/g, and the adsorption process could be accurately described by quasi-second order kinetics model and Langmuir model. The adsorption thermodynamics revealed that the adsorption was a spontaneous, endothermic, and entropy-increasing process. TGO/P(SSS-co-AA) aerogel exhibited highly selective adsorption property and excellent regeneration performance. Even following five regeneration cycles, adsorption capacity of the aerogel could still maintain 936.09 mg/g. In conclusion, TGO/P(SSS-co-AA) aerogel exhibited exceptional performance as an adsorbent for removing MB, providing an inspiration for the construction of GO-based composite aerogel and its actual application in efficient and selective wastewater treatment.

Construction of magnetic covalent organic frameworks based on the monomer-mediated in situ layer-by-layer growth strategy for efficient gold recovery

Creating uniform magnetic covalent organic framework (MCOF) adsorbents for effectively capturing and separating gold presents a considerable challenge. However, achieving this uniformity is crucial for resource recycling and environmental protection. This study introduces a monomer-mediated in situ layer-by-layer growth strategy employing a timed injection method for fabricating magnetic covalent organic frameworks. The hybrid MCOFs produced, Fe3O4@SiO2@COF and Fe3O4@SiO2@COF-DMSA, possess abundant binding sites that enhance adsorption capacities, rapid kinetics, and remarkable regeneration performance for gold recovery. Significantly, the Fe3O4@SiO2@COF exhibits a lower gold adsorption capacity (898 mg g−1), whereas Fe3O4@SiO2@COF-DMSA exhibits an improved Au (III) selectivity and a larger capacity for adsorption (1116 mg g−1). The capturing mechanism of Au (III) by Fe3O4@SiO2@COF-DMSA is predominantly attributed to coordination and reduction, as identified through XPS analysis. This study motivates conceptualizing molecular/ionic capture strategies using core–shell NP/COF hybrid materials to retrieve precious metals.

Efficient fluoride removal in hybrid capacitive deionization enabled by Ce-Zn-MOF-derived CeO2@C and birnessite electrodes

Fluorine pollution has become a public health issue of global concern. Capacitive deionization (CDI) presents the benefits of simple operation, high energy efficiency, and good sustainability. The development of high adsorption performance, economical and environmentally friendly defluorination electrodes is the key direction of capacitive deionization. Here, a spherical metal–organic framework (MOF) Ce/Zn-BTC was prepared by solvothermal method utilizing benzene-tricarboxylic (BTC) acid as solvent, and then it was transformed into CeO2@C composites through pyrolysis. The spherical structure of the original MOFs is preserved by CeO2@C, leading to significant enhancements in specific surface area (275.48 m2/g), pore volume (0.3359 cm3/g), and electrochemical performance. In this work, the anode material CeO2@C was employed for the first time, while birnessite-type MnO2 (δ-MnO2) was utilized as a cathode material for the fabrication of a hybrid CDI (HCDI) device for the treatment of fluorinated wastewater. The CeO2@C/δ-MnO2 cell shows excellent fluoride removal performance with a removal capacity of 22.03 mg/g for 50 mg/L fluoride solutions under a 1.2 V applied voltage, which is better than most carbon-based materials. Importantly, the CeO2@C/δ-MnO2 cell has favorable fluoride selectivity and regeneration performance (>75 %) even after undergoing ten cycles. Fluoride is mainly removed by intercalation into the carbon skeleton, coordination with Ce, and electrostatic interaction. This study shows that the CeO2@C/δ-MnO2 cell has excellent fluoride removal performance and practical application prospects.

Green and rational design of Ln4Zn2L2 heteromultimetallic complexes for mild and highly efficient CO2 conversion

Reasonable and high efficient utilization of carbon dioxide (CO2) has always been considered as a kind of green and sustainable development strategy. However, the efficient chemical conversion of CO2 into value-added products has been limited due to lack of efficient catalysts. Herein, two novel heterometallic hexanuclear complex catalysts (viz Nd4Zn2L2 (1) and Eu4Zn2L2 (2)) were designed and synthesized, which featuring unique hetero-multinuclear units. The heterometallic hexanuclear complex catalysts not only have multi-bimetallic catalytic sites (Ln3+ and Zn2+) which can absorb more molecules and be beneficial to the improvement of catalytic performance, but also have the potential to further expand the chemical fixation of CO2 with epoxides avoid the harsh reaction conditions. Using the synthesis of propylene carbonate (PC) by cycloaddition reaction of propylene oxide (PO) and CO2 as a model reaction, the as-prepared catalysts and catalytic system showed high turnover frequencies (TOFs) under the mild condition instead of harsh reaction conditions. More importantly, these catalysts can be reused to preserve the structure's integrity and retain their catalytic activity at the same level even after five rounds of catalysis. The excellent regeneration performance indicated that the as-prepared heterometallic hexanuclear complex catalysts can be reused many times. In addition, the catalytic system also exhibited a wide range of substrates for epoxide. These results predict that the proposed heterometallic hexanuclear complex catalysts and catalytic system have great potential toward CO2 adsorption and catalytic conversion. This work may build up a new synthetic route for tailoring more new heterometallic complex catalysts with excellent catalytic activity and applied in various fields of application.