One-pot Hydrothermal Reaction Research Articles

Iron ion detection and life cycle assessment of cutting fluid based on photoluminescent nitrogen-doped carbon quantum dots

Cutting fluid (CF) ensures machining accuracy and improves tool life in machining, which is of great significance for its impurity content detection and life cycle evaluation. In this paper, citric acid and arginine were used as carbon and nitrogen sources, photoluminescent (PL) nitrogen-doped carbon quantum dots (N-CDs) with a particle size ranging from 8 to 14 nm and well dispersion in water-based CF were synthesized by a one-pot hydrothermal reaction method. The N-CDs have the best signal under 360 nm ultraviolet light excitation, which well avoids the autofluorescence of the CF. The N-CDs dispersion have good selectivity and linearity in the Fe3+ concentration range of 2 to 80 μM, and the detection limit is 1.2 μM. The N-CDs were used to detect the concentration of Fe3+ in CF with different working hours, and the results were consistent with the results of coupled plasma emission spectroscopy. This study provides an intelligent sensing platform for the highly sensitive and selective detection of Fe3+ in the CF environment, and provides a promising strategy for the evaluation of the CF lifetime.

Luminescent metal-organic framework sensor for detection of biomarker 2-thiothiazolidine-4-carboxylic acid

Using terephthalic acid (BDC) as the organic ligand and zirconium chloride (ZrCl4) as the metal source, a lanthanide metal-organic framework (Tb/Zr-UiO-66) with excellent luminescence properties was successfully prepared by introducing the lanthanide ion Tb3+in situ through a simple one-pot hydrothermal reaction, which was designed as an optical biosensor for 2-thiothiazolidine-4-carboxylic acid (TTCA), the urinary biomarker of human exposure to carbon disulfide (CS2). The fabricated Tb/Zr-UiO-66 exhibits high chemical and luminescent stability, making it competent for recognizing TTCA in aqueous environments. Significantly, its luminescence intensity change shows a good linearity relationship with the concentration of TTCA in the range of 0–110 µM, with a limit of detection (LOD) as low as 0.14 µM. Meanwhile, this sensor exhibits good selectivity and anti-interference ability towards TTCA among the various coexisting components in urine (Na+, K+, NH4+, SO42−, Cl −, creatine, creatinine, glucose, urea, etc.), and can quickly respond to TTCA within 2 min. The analysis results of powder X-ray diffraction (PXRD), fluorescence lifetime and ultraviolet–visible (UV–vis) spectrum demonstrate that the sensing mechanism can be ascribed to the competition absorption effect between TCAA and Tb/Zr-UiO-66. This biosensor with simple synthesis, stable framework, high sensitivity and selectivity, and rapid response has potential to become a powerful tool for diagnosing diseases associated with CS2 exposure.

Protective and Flame-Retardant Bifunctional Epoxy-Based Nanocomposite Coating by Intercomponent Synergy between Modified CaAl-LDH and rGO.

Extensive utilization in various settings poses extra requirements of coatings beyond just anticorrosion properties. Herein, 8-hydroxyquinoline (8-HQ) intercalated CaAl-based layered double hydroxide (CaAl-8HQ-LDH) was loaded on reduced GO (rGO) through a one-pot hydrothermal reaction, which was employed as the nanofiller endowing the epoxy (EP/CaAl-8HQ LDH@rGO) with excellent flame-retardancy while ensuring efficient protection for mild steel. Results of electrochemical impedance spectroscopy (EIS) demonstrated the durability of the EP/CaAl-8HQ LDH@rGO-coated specimen, with the impedance at the lowest frequency (|Z|0.01Hz) maintained as 1.84 × 1010 Ω cm2 after 120 days of immersion in a 3.5 wt % NaCl solution. Even for the scratched EP/CaAl-8HQ LDH@rGO system, only a slight decline in |Z|0.01Hz was observed during 180 h of exposure to the NaCl solution, indicating a self-healing feature supported by salt spray tests. UL-94 burning tests revealed the V-0 rating for EP/CaAl-8HQ LDH@rGO with improved thermostability. Strong physical barrier from two-dimensional rGO and the release of 8-HQ from LDH interlayers accounted for the anticorrosive and self-healing properties. However, O2-concentration dilution and charring-layer promotion governed the flame-retardant behavior of the nanocomposite coating. The intercomponent synergy of nanofillers achieved in this work may provide a useful reference for designing multifunctional coatings.

One-pot direct conversion of passion fruit hull into 5‑hydroxymethylfurfural catalysed by halogenated metal ionic liquids and organic acids

Biomass serves as a crucial source of renewable energy and potential raw materials for synthesizing various value-added chemicals. This study explored the direct conversion of the cellulose of passion fruit shells into 5-hydroxymethylfurfural (5-HMF), a promising substitute for fossil-derived compounds, by combining halogenated metal ionic liquids (ILs) and organic acids through one-pot hydrothermal reaction. Factors such as the type of ILs and organic acids, reaction time and temperature, as well as the quantity of dimethyl sulfoxide (DMSO) in the solvent, and the loading of substrate, IL, and organic acid were investigated for their impact on 5-HMF yield. Optimization of reaction conditions led to the attainment of the highest 5-HMF yield, reaching 33.1 ± 0.34 % based on the cellulose content within the passion fruit shell. Furthermore, the structural and morphological changes of the solid residues were analysed through techniques such as Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). These analyses revealed the progressive conversion of cellulose, hemicellulose, and lignin, accompanied by the formation of humin by-products. This integrated approach for 5-HMF production from agricultural waste introduced novel possibilities for transforming sustainable biomass resources into valuable chemical products.

Preparation and catalysis of defected PVMo4W7@rht-MOF-1 for oxidation desulfurization under air

Aerobic oxidative desulfurization (AODS) is a promising deep desulfurization technique that can efficiently remove organosulfur compounds under mild conditions. In this study, a one-pot hydrothermal method was designed to encapsulate a quaternary heteropolyacid H4PVMo4W7O40 (PVMo4W7) into rht-MOF-1 {rht-MOF-1 = [Cu6O(TZI)3(H2O)6]4⋅nH2O}, and the single crystal structure of H4PVMo4W7O40@rht-MOF-1 (1) indicated that PVMo4W7 was effectively encapsulated within cage C of rht-MOF-1. Further, a similar one-pot hydrothermal reaction was employed to introduce acetic acid, resulting in the synthesis of defective H4PVMo4W7O40@rht-MOF-1-De (1-De). 1-De was characterized using various techniques such as FT-IR, XRD, TGA, XPS, and EPR. In comparison with 1, 1-De exhibited numerous defect sites, high porosity, high surface area, high Mo5+ ion content, well-dispersed PVMo4W7, and abundant oxygen vacancies, leading to efficient AODS capability. When applied as catalyst, 1-De demonstrated high catalytic activity and good recyclability for the oxidation of dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT) under air atmosphere. Strikingly, the removal rates of DBT and 4,6-DMDBT reached 99 % and 96 %, respectively under optimized conditions.

Efficient adsorption removal of 2,4-dichlorophenoxyacetic acid using amine-functionalized metal–organic frameworks (MOFs): Performance and mechanisms

2,4-dichlorophenoxyacetic acid (2,4-D) is a widely used herbicide and plant growth regulator worldwide; however, its overdose and improper use would cause severe eco-toxicological effects on aquatic life, plants, and human life. This work synthesized high-quality MIL-101(Cr)-NH2 nanoparticles via a one-pot hydrothermal reaction and used it in pioneer as an amine-functionalized mesoporous metal–organic frameworks (MOFs) adsorbent for 2,4-D removal. The adsorption kinetics results confirmed that MIL-101(Cr)-NH2 obeys the pseud-second-order kinetic model, and the isotherm results imply that it shows multilayer adsorption following the Freundlich model. Compared to state-of-the-art benchmark MOF adsorbent UiO-66-NH2, MIL-101(Cr)-NH2 achieved a superior 2,4-D adsorption capacity of 348.5 mg/g at pH = 7 with a nearly 50 % increase in adsorption removal rate under ambient conditions. Spectroscopy analysis and density functional theory (DFT) calculations revealed that the distinct large pore size, high surface area and porosity of MIL-101(Cr)-NH2 are the essential physical factors for enhancing the diffusion ability of 2,4-D in the framework. Meanwhile, the electrostatic interactions of the metal clusters and aminated benzene ring with the dissociated 2,4-D anion are the dictated binding forces during adsorption. This mechanism was further validated by the adsorption behaviors of other contaminants over the two MOF adsorbents. Furthermore, the MIL-101(Cr)-NH2 nanoparticles can be chemically anchored onto chitosan to form MIL-101(Cr)-NH2/Chitosan foams with feasible recovery ability and it was found that the MIL-101(Cr)-NH2/Chitosan (1/3) foam showed a comparable 2,4-D removal rate to UiO-66-NH2 (52.2 % vs. 57.7 %). This study reported a high-performance aminated MOF adsorbent for 2,4-D removal and the revealed adsorption mechanisms offer an excellent platform for rational design of advanced adsorbents for acidic contaminants adsorption.

One-Pot Hydrothermal Synthesis of mSiO2-N-CDs with High Solid-State Photoluminescence as a Fluorescent Probe for Detecting Dopamine

An effective fluorescent probe (mSiO2-N-CDs) was prepared by embedding N-CDs into mesoporous silica via a simple one-pot hydrothermal reaction and applied to the detection of dopamine (DA). Mesoporous silica not only provided a skeleton to prevent the aggregation of N-CDs but also a medium for the centrifugal collection of N-CDs, avoiding the need for dialysis and freeze-drying. The formation process, phase composition, morphology, and luminescence properties of the composite were studied in detail. The synthesized mSiO2-N-CDs possessed spherical morphology, a smooth surface, and a diameter of approximately 150 nm. The fluorescence results indicated that mSiO2-N-CDs emitted intense blue color fluorescence at 465 nm under the optimal excitation of 370 nm. Because the mesoporous silica effectively inhibited the self-quenching caused by the aggregation of N-CDs, the quantum yield of solid mSiO2-N-CDs powder reached 32.5%. Furthermore, the emission intensity of the solid mSiO2-N-CDs remained constant for 28 days. The good sensitivity and selectivity of mSiO2-N-CDs for DA enabled the establishment of a rapid, simple, and sensitive DA detection method. The linear range was 0–50 µM and the limit of detection was calculated to be 107 nM. This method was used for the determination of DA in urine, with recovery rates ranging between 98% and 100.8%. In addition, the sensing mechanism was characterized by fluorescence lifetime decay and UV–VIS spectral analysis.

Development of a biomimetic DNA delivery system by encapsulating polyethyleneimine functionalized silicon quantum dots with cell membranes.

Quantum dots (QDs) are renowned for their remarkable optoelectronic properties, making them suitable for applications such as bioimaging and optoelectronics. However, their use in gene delivery has been restricted due to the low DNA loading capacity. This study aimed to develop a biomimetic DNA delivery system by encapsulating polyethyleneimine (PEI) functionalized silicon QDs (SiQDs) with cell membranes and evaluate its potential as a gene vector in vitro. To achieve this, hydrophilic dispersed silicon QDs (PQDs) were prepared through a one-pot hydrothermal reaction of PEI and 3-Aminopropyltrimethoxysilane (APTMS). Subsequently, red blood cell membrane (RBCM) encapsulated biomimetic QDs (CM-PQDs) was obtained through the extrusion method. The CM-PQDs exhibited higher DNA loading capacity and better stability than naked SiQDs. The CM-PQDs/DNA complex was effectively taken up by cells, as observed through the fluorescence characteristics of QDs themselves. Both CM-P10QDs (prepared with PEI10k) and CM-P25QDs (prepared with PEI25k) could deliver DNA into cells and express the reporter protein successfully. CM-P25QDs showed a higher transfection efficiency of 77.32% in 293T cells and 47.11% in HeLa cells than SiQDs and CM-P10QDs. The results also indicated that cell membrane encapsulation could effectively reduce the cytotoxicity of SiQDs further. Therefore, the study concludes that CM-PQDs have the potential to serve as a safe and traceable biomimetic gene delivery system.

Rapid Trace Detection of Sulfite Residue in White Wine Using a Multichannel Colorimetric Nanozyme Sensor.

As a commonly used food additive, sulfite (SO32-) is popular with food manufacturers due to the functions of bleaching, sterilizing, and oxidation resistance. However, excess sulfites can pose a threat to human health. Therefore, it is particularly important to achieve rapid and sensitive detection of SO32-. Herein, a colorimetric sensor was invented for visual, meticulous, and rapid detection of SO32- based on MIL-53(Fe/Mn). Bimetallic nanozyme MIL-53(Fe/Mn) was prepared by a one-pot hydrothermal reaction. The prepared MIL-53(Fe/Mn) can effectively catalyze the oxidation of colorless TMB to a blue oxidation product (oxTMB). The introduction of SO32- causes significant discoloration of the reaction system, gradually transitioning from a visible blue color to colorless. Hence, a sensitive colorimetric sensor for SO32- detection was developed based on the decolorization degree of the detection system. Further, the discoloration was ascribed to the inactivation of nanozyme and the strong reducing ability of SO32-. Under the optimal experimental conditions, there was a good linear relationship between the absorbance at 652 nm and SO32- concentration in the linear range of 0.5-6 μg mL-1 with a limit of detection (LOD) of 0.05 μg mL-1. The developed method was successfully applied to the detection of actual samples of white wine with good accuracy and recovery. Compared to traditional methods, this colorimetric sensor produces similar detection results but significantly reduces the detection time. Compared to traditional methods, this colorimetric sensor can not only reduce the detection costs effectively but also help the food industry maintain quality standards. Strong anti-interference capability, simple operation, and low detection limits ensure the excellent performance of the colorimetric sensor in detecting SO32- in white wine. The combination of a smartphone and a colorimetric analysis application has also greatly facilitated the semi-quantitative, visual on-site detection of SO32-, which has opened up an application prospect of an MIL-53(Fe/Mn)-based detection platform. Our work has indicated a new direction for the detection of SO32- and provided important assurance for food safety.

Synthesis of polymorphic CoSe2@MoSe2 microspheres with hollow and core-shell structures for electromagnetic wave absorption

Structure design and surface morphology control are effective strategies for preparing electromagnetic wave absorbing (EWA) materials with superior performance. In this work, Co microspheres with large diameters and rough surfaces were prepared by a simple solvothermal reaction. Then, through a one-pot hydrothermal reaction with Se and Mo sources, the Co was changed into polymorphic CoSe2 and loaded with a layer of MoSe2 nanosheets. Moreover, as the Co cations migrated outside to react with Se, free space was generated inside the spheres; thus, hollow and core-shell structures were achieved. The synthesized CoSe2@MoSe2 complex can cause dielectric and magnetic loss at the same time, achieving a minimum reflection loss of -45 dB and a maximum effective absorption bandwidth of 6 GHz. This work provides insight regarding the utility and massive synthesis of Co microspheres and advanced EWA materials with unique structures and diverse loss modes.

Recycling of stainless steel pickling wastewater and polyethylene terephthalate plastic: A total-waste synthesis of metal-organic framework

Metal-organic frameworks (MOFs) attract considerable interests in various fields while relatively high cost limits their industrial-level use. Herein, we proposed a total-waste preparation route for Fe/Cr-MIL-88B (MIL, Matérial Institut Lavoisier), in which stainless steel pickling wastewater (PW) and waste polyethylene terephthalate (PET) act the total raw materials. Interestingly, PET is easily decomposed to terephthalic acid (H2BDC) under the strong acid environment of PW. Benefited from that, the formation of MOFs from PET and PW can be achieved via one-pot hydrothermal reaction, superior to the traditional two-step method. The obtained MIL-88B exhibits long-term acid/base stability and high removal efficiency for zirconium (IV) ion. Besides, the structure and adsorption performance of the products are not controlled by the discharge batch of the pickling wastewater, indicating the feasibility for continuous production in industry. Thus, our work provides a feasible route for preparing low-cost MOFs and recycling industrial wastes.

Fluorometric Assay of Tyrosinase and Atrazine Based on the Use of Carbon Dots and the Inhibition of Tyrosinase Activity.

Sensitive and convenient strategy of tyrosinase (TYR) and its inhibitor atrazine is in pressing demand for essential research as well as pragmatic application. In this work, an exquisite label-free fluorometric assay with high sensitivity, convenience and efficiency was described for detecting TYR and the herbicide atrazine on the basis of fluorescent nitrogen-doped carbon dots (CDs). The CDs were prepared via one-pot hydrothermal reaction starting from citric acid and diethylenetriamine. TYR catalyzed the oxidation of dopamine to dopaquinone derivative which could quench the fluorescence of CDs through a fluorescence resonance energy transfer (FRET) process. Thus, a sensitive and selective quantitative evaluation of TYR can be constructed on the basis of the relationship between the fluorescence of CDs and TYR activity. Atrazine, a typical inhibitor of TYR, inhibited the catalytic activity of TYR, leading to the reduced dopaquinone and the fluorescence was retained. The strategy covered a broad linear range of 0.1-150 U/mL and 4.0-80.0 nM for TYR and atrazine respectively with a low detection limit of 0.02 U/mL and 2.4 nM/mL. It is also demonstrated that the assay can be applied to detect TYR and atrazine in spiked complex real samples, which provides infinite potential in application of disease monitoring along with environmental analysis.

Zinc-Based Tannin-Modified Composite Microparticulate Scaffolds with Balanced Antimicrobial Activity and Osteogenesis for Infected Bone Defect Repair.

Treatment of infected bone defects is a major clinical challenge; bioactive materials combining sufficient antimicrobial activity and favorable osteogenic ability are urgently needed. In this study, through a facile one-pot hydrothermal reaction of zinc acetate in the presence of tannic acid (TA), with or without silver nitrate (AgNO3 ), is used to synthesize a TA or TA and silver nanoparticles (Ag NPs) bulk-modified zinc oxide (ZnO) (ZnO-TA or ZnO-TA-Ag), which is further composited with zein to fabricate porous microparticulate scaffolds for infected bone defect repair. Bulk TA modification significantly improves the release rate of antibacterial metal ions (Zn2+ release rate is >100 times that of ZnO). Fast and long-lasting (>35 d) Zn2+ and Ag+ release guaranteed sufficient antibacterial capability and excellent osteogenic properties in promoting the osteogenic differentiation of bone marrow mesenchymal stem cells and endogenous citric acid production and mineralization and providing considerable immunomodulatory activity in promoting M2 polarization of macrophages. At the same time, synchronously-released TA could scavenge endogenous reactive oxygen species (ROS) and ROS produced by antibacterial metal ions, effectively balancing antibacterial activity and osteogenesis to sufficiently control infection while protecting the surrounding tissue from damage, thus effectively promoting infected bone defect repair.

Coral-shaped Mn-CuS with hierarchical pores and crystalline defects for high-efficiency H2O2 production via electrocatalytic two-electron reduction

We report the development of non-noble transition metal sulfide catalysts Mn-CuS-x for high-efficiency and selective H2O2 production. In this study, we synthesized Mn-CuS-x with coral-shaped hierarchical porous structure through one-pot hydrothermal reaction. The Mn-CuS-x possesses large specific surface area with plenty of crystalline defects via heteroatom doping of Mn. The Mn-CuS-x kinetically favored 2e− pathway over 4e− pathway, resulting in high selectivity (>92%) to H2O2 production and high H2O2 concentration (∼24.5 mM at 0.6 V vs. RHE) within 3 h for the optimized Mn-CuS-2 catalysts (synthesized with a molar ratio of 1:3:8 (MnCl2·4 H2O: CuCl2·2 H2O: C2H5NS)). The Mn-CuS-2 showed excellent stability, indicating that the Mn-CuS electrocatalysts can simultaneously achieve both high stability and enhanced H2O2 production. Our first-principles calculations further confirmed that the heteroatom Mn doping to CuS thermodynamically makes the 2e–-ORR pathway more favorable. This study provides a green, low-cost, and efficient route to produce H2O2, which is very promising for generating chemicals and liquid fuels.

A new copper(II) complex containing triclopyr: one-pot crystallization, structure, conformation and Hirshfeld surface analyses

Abstract A new copper(II) complex [Cu(3,5,6-tcpa)(2,2′-bipy)Cl] (1) has been obtained through the one-pot hydrothermal reaction of copper chloride dihydrate with triclopyr (systematic name 2-((3,5,6-trichloropyridin-2-yl)oxy)acetic acid, abbreviation 3,5,6-Htcpa) and 2,2′-bipyridine (2,2′-bipy) coligands. 1 has crystallized in triclinic crystal system, P 1 ‾ $\overline{1}$ space group. The central copper(II) ion displayed a distorted square–pyramidal geometry and was connected by one chlorido co-ligand (Clˉ), one 3,5,6-tcpa anionic chelator and one chelating 2,2’-bipy ligand to afford a mononuclear structure. 1 is further extended into a 3D network by the non-covalent interactions of H⋯Cl, H⋯O hydrogen bonds, aromatic π⋯π stacking together with Cl⋯Cl halogen bond interactions. The co-crystallization process, the crystal structure of 1 as well as the Hirshfeld surface analysis for 1 have been analyzed and described. In addition, the flexible conformation of phenoxy methylene group among 1, triclopyr acid and its previously reported co-crystallized compound also have been carefully compared and discussed.

Hierarchical flower-like MoS2/reduced graphene oxide nanohybrids supported on nickel foam as a high-performance electrode material for supercapacitor applications

Flower-like MoS2/rGO nanohybrids have been synthesized using one-pot hydrothermal reaction method. The supercapacitor cell exhibited excellent electrochemical performance predominated by surface capacitive processes.

One-Pot Preparation of FeSe-WSe2 Composite and the Performance of Photo Fenton to Degradation Methylene Blue

FeSe-WSe2 composite photocatalyst was synthesized by a facile one-pot hydrothermal reaction with WSe2, sodium selenite (Na2SeO3), hydrazine hydrate (N2H4and#183;H2O), hydrochloric acid (HCl), and Ferric chloride (FeCl3). Different ratios of FeSe-WSe2 composite photocatalysts were synthesized according to different Fe content, and FeSe-WSe2 was characterized by XRD, SEM, UV-vis DRS and XPS. At the same time, the photocatalytic performance and catalytic mechanism of the composite photocatalyst were explored through the degradation of methylene blue (MB) by the composite. The experimental results show that under the best experimental conditions, the 37at% (Atomic ratio) FeSe-WSe2 composite has the best removal effect on MB solution, and the removal rate reaches 99.8%. This shows that there is a synergistic effect of photocatalysis and Fenton reaction, which greatly improves the degradation ability of pollutants of FeSe-WSe2. Since the degradation of pollutants by photo Fenton is carried out under neutral conditions, it is more conducive to future applications in actual production.

Constructing interface engineering and tailoring a nanoflower-like FeP/CoP heterostructure for enhanced oxygen evolution reaction.

The inexpensive and highly efficient electrocatalysts toward oxygen evolution reaction (OER) in water splitting electrolysis have displayed promising practical applications to relieve energy crisis. Herein, we prepared a high-yield and structurally regulated bimetallic cobalt-iron phosphide electrocatalyst by a facile one-pot hydrothermal reaction and subsequent low-temperature phosphating treatment. The tailoring of nanoscale morphology was achieved by varying the input ratio and phosphating temperature. Thus, an optimized FeP/CoP-1-350 sample with the ultra-thin nanosheets assembled into a nanoflower-like structure was obtained. FeP/CoP-1-350 heterostructure displayed remarkable activity toward the OER with a low overpotential of 276 mV at a current density of 10 mA cm-2, and a low Tafel slope of only 37.71 mV dec-1. Long-lasting durability and stability were maintained with the current with almost no obvious fluctuation. The enhanced OER activity was attributed to the presence of copious active sites from the ultra-thin nanosheets, the interface between CoP and FeP components, and the synergistic effect of Fe-Co elements in the FeP/CoP heterostructure. This study provides a feasible strategy to fabricate highly efficient and cost-effective bimetallic phosphide electrocatalysts.

Synchronously boosting microwave-absorbing and heat-conducting capabilities in CeO2/Ce(OH)3 core-shell nanorods/nanofibers via Fe-doping amount control.

To address the electromagnetic interference (EMI) and heat dissipation issues in electronics, we pioneered the synthesis of Fe-doped CeO2/Ce(OH)3 core-shell nanorods/nanofibers (CSNRs/NFs) through a simple one-pot hydrothermal reaction. The growth of core-shell nanofibers was driven by the minimal surface free energy and vacancy formation energy. By controlling the amount of Fe-doping, not simply Fe0 content, crystallite size, defects, impurities, and length/diameter ratios could be modulated, but the electric, magnetic, thermal, and microwave absorption performance. The efficient 3D network constructed by 1D nanofibers in a silicone matrix offered a continuous pathway for electrons/phonon relay transmission, endowing the composites with exceptional heating conductance (3.442 W m-1 K-1) at 20%Fe-doping. An ultrawide absorption band (9.26 GHz) with intense absorption (-42.33 dB) and small thickness (1.7 mm) was achieved at 10%Fe-doping due to excellent matching performance, strong attenuation ability, and large EM parameters. Overall, Fe-doped CeO2/Ce(OH)3 CSNFs are a promising material for next-generation electronics with effective heat dissipation and EM wave absorption due to their straightforward process, mass production, and outstanding comprehensive performance. Beyond providing a deeper insight into the accurate defect modulation in magnetic-dielectric-double-loss absorbents by doping, this paper proposes an electron/phonon relay transmission strategy to improve heat conductance.

Green conversion of excess sludge to N-Ca self-doping sustainable carbon quantum dots with remarkable fluorescence enhancement and residual heavy metal reduction

“Waste” is “Wealth”. Recovering valuable materials from excess sludge (ES) is trending as an efficient strategy that synergizes waste management and resource recovery. Targeting the inherent composition characteristics of ES, this study aimed to explore resource recovery strategies that can exert its unique advantages. ES from paper mill was unprecedently selected as the carbon precursor, and ES-derived carbon quantum dots (ESCQDs) were successfully synthesized via a facile and one-pot hydrothermal reaction without pretreatments, catalysts or any additives. Notably, its fluorescence quantum yield (QY) and mass recovery rate were as high as 28.472 % and 2.86 %, respectively, which were at a high level among biomass-derived CQDs. N-Ca was successfully co-doped into ESCQDs without any nitrogen or calcium amendment, which has been reported rarely. The effect of Ca doping on the enhancement of QY of CQDs was revealed, thereby revealing the natural advantageous properties of ES from paper mill in the synthesis of high fluorescent Ca-N co-doped CQDs. Furthermore, the effect of the preparing ESCQDs on the environmental risks control of ES were also investigated. This resource recovery process efficiently removed residual heavy metals from ES and significantly reduced and controlled the environmental risk of heavy metals in ES, and the synthetic ESCQDs had low toxicity and excellent biocompatibility. This study proposed a green alternative that combines the recovery of value-added products from ES with heavy metal control, provided more in-depth understanding for the formation mechanism of CQDs, and revealed structural strategies for the preparation of high fluorescent CQDs.