To achieve fire-resistant epoxy resin (EP), a UiO-66-based novel flame retardant coating (CS@APP@UiO-66) was prepared by modifying UiO-66 with chitosan (CS) and ammonium polyphosphate (APP) through a layer-by-layer (LbL) self-assembly method, which was then introduced into an EP system to improve its fire safety. The results of scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy show that the unsaturated Zr atoms in the UiO-66 framework provide many active sites conducive to modification, so that the UiO-66 particles, which originally had a regular octahedral structure, are more dispersed by LbL modification without causing doping or distortion issues. The thermogravimetric analysis results indicate that the char residue of EP/2% UiO-66 is increased by 2.52% compared with that of pure EP, indicating that the thermal properties of the EP composite are improved after modification. In addition, the cone test results indicate that EP/2%UiO-66-5L has good flame retardancy and smoke suppression properties, and the peak heat release rate, total smoke production and rate of CO generation values are 25.2%, 5.7% and 38.5% lower than those of the unmodified EP. Moreover, it can be concluded from the Raman test that the graphitization degree of the modified EP composite is strengthened. The above results indicated that after the incorporation of CS@APP@UiO-66 into the EP composites, more char layers formed as physical barriers to prevent the transfer of mass and heat, thus reducing the speed of flame propagation. Therefore, the flame resistance and smoke suppression of the EP composites improved. These favorable characteristics, including high flame retardant efficiency and good smoke suppression, make LbL-functionalized UiO-66 promising for flame retardant polymer applications.

Copper-based catalysts play a pivotal role in CO₂ electroreduction (CER) toward multi-carbon (C₂₊) products. However, achieving a high selectivity for C₂₊ products remains a formidable challenge. In this work, a facile electrochemical oxidation-reduction technique was developed to modulate the surface morphology of a copper foil using sulfur and oxygen as auxiliary atoms. Optimization of this approach resulted in an atomically reconstructed copper electrode (denoted as Cu-50) with a surface tensile strain of 1.1% and preferential exposure of Cu(100) facets. Cu-50 delivered remarkable Faradaic efficiencies (up to 72%) for C₂₊ products during CER, with a 53% selectivity for ethylene (10-fold higher than for a non-reconstructed Cu foil). This work guides the design of advanced copper-based catalysts that promote C–C coupling, demonstrating the potential of tailored copper structures for efficient conversion of CO₂ to valuable C₂₊ products.

In this work, Fe/Ru-catalyst supported on hyper-crosslinked polystyrene (HPS) synthesized via hydrothermal deposition was proposed for the Fischer-Tropsch synthesis (FTS) to obtain a high yield of gasoline-ranged hydrocarbons. According to the characterization results, the obtained monometallic 2%Fe-HPS catalyst contains Fe₃O₄ particles with a multimodal distribution (mean particle size of 11, 30, and 45 nm). The addition of Ru leads to a decrease in the particle size with a narrower distribution (ca. 5 nm). Ru was shown to serve as a nucleating agent for Fe₃O₄ crystalline since it has a higher affinity to the HPS surface and strongly anchors to the benzene rings of the polymer. This prevents a leaching of the active phase from the support increasing the catalyst stability. Ru addition also brings supplemental sites for CO and H₂ chemisorption resulting in 1.5-fold increased activity in FTS reaction compared to monometallic 2%Fe-HPS composite. 2%Fe-1%Ru-HPS composite showed ~20% higher selectivity toward the formation of C₅–C₁₁ alkanes at about 30% conversion of CO in comparison with monometallic one. Moreover, the branched hydrocarbons with a selectivity of approximately 17.5 mol% were observed in the FTS products in the presence of a 2%Fe-1%Ru-HPS catalyst.

Using the chemically stable and cost-effective nylon PA6 as a substrate with the help of the high hydrophilicity of microcrystalline cellulose (MCC) and TiO₂ nanoparticles to build micro-nanostructures on the surface of the nylon PA6, the superhydrophilic and underwater oleophobic composite membrane was fabricated to achieve the high efficiency of water–oil separation. TiO₂ nanoparticles wrapped in MCC were evenly dispersed on the composite membrane, and the pore size of the composite membrane decreased with increasing MCC mass fraction. MCC can be tightly bound to the surface of the PA6 membrane because of its excellent film-forming properties and ability to cross-link with PA6. The modification of TiO₂ and MCC led to a reduction in the surface adhesion of the composite membrane to oil droplets. The separation efficiency of the composite membrane for water–oil emulsions followed the order TiO₂@2MCC-PA6 > TiO₂@MCC-PA6 > TiO₂-PA6 > PA6, and the change in filtration flux was exactly the opposite. TiO₂@MCC-PA6 was the best composite membrane for three water–oil emulsions with sodium dodecyl sulfate (SDS), and its separation efficiency was over 96%. The water contact angle and underwater oil contact angle of TiO₂@MCC-PA6 changed slightly after it was immersed in acidic and alkaline solutions for 36 h. The filtration flux and separation efficiency of TiO₂@MCC-PA6 for n-hexane/SDS/water were still above 3100 L·m ⁻²·h⁻¹·bar⁻¹ and 93%, respectively, after 50 cycles.

Municipal sludge (MS) extract obtained by degradative solvent extraction has the typical fuel characteristics of high nitrogen content, zero moisture, and low ash, which is suitable for producing valuable nitrogen-containing chemicals. This study compared the nitrogen-rich pyrolysis characteristic of MS extracts using thermogravimetric/thermogravimetric-mass spectrometry/pyrolysis-gas chromatography-mass spectrometry. The composition of bio-oil from catalytic pyrolysis of MS extracts with HZSM-5 was studied, and the pyrolysis kinetic models was established. The results show that different from the raw MS pyrolysis, the MS extracts pyrolysis all had two main peaks with similar values in the range of 140–530 °C (Stage L and Stage W). NH₃ is mainly released in the range of 140–370 °C (Stage L), and the nitrogen-containing compounds content in the bio-oil in this stage is 41.81%. After adding HZSM-5, the weight loss rate in Stage L decreased by 21.97%, while that in Stage W increased by 10.04%. An obvious weight loss peak (30.32%) appeared at the temperature of 530–900 °C, which is due to the increased fixed carbon content (increased by 16.07%) of the bio-oil from catalytic pyrolysis. The number of components in the nitrogen-containing compounds decreases much, however, its yield increases by 9.45% due to the transformation of nitrogen by the catalyst effect of HZSM-5 adding.

The sodium persulfate (Na₂S₂O₈)-urea system has been proven to be an excellent scrubbing solution for the wet removal of NO. Commonly, seawater is used as a wet carrier in marine applications. To further explore the feasibility of marine denitrification using Na₂S₂O₈-urea system, this study proposed the Na₂S₂O₈-urea-seawater composite redox system for NO removal from the marine exhaust gas. The effects of seawater carrier, reaction temperature, Na₂S₂O₈ concentration, urea concentration, pH value, and NO concentration on NO removal were investigated. Additionally, the NO₃⁻ concentration in the solution was measured. Results showed that the lowest normalized NO concentration was 0.099, with the corresponding mass of NO absorbed per unit volume of solution reaching 0.108 g·L⁻¹. The addition of seawater carrier and incremental reaction temperature, Na₂S₂O₈, and urea concentration promoted the NO removal performance. When the pH value increased within the range of 4–7, the NO removal performance decreased. The NO removal performance increased as the pH value further increased to 8, but decreased again when the pH value increased to 11. An increase in NO concentration was detrimental to NO removal. The Cl⁻, HCO₃⁻, and CO₃²⁻ in seawater could augment the total concentration of active free radicals to improve denitrification performance.

Tetracycline is a broad-spectrum antibiotic that can rapidly inhibit bacterial growth, but its excessive usage and improper handling can lead to its discharge into water, soil, and other ecosystems, posing a significant hazard to ecology and human health. Photocatalysis is considered the most attractive solution for addressing this problem. However, most photocatalysts suffer from nanoparticle agglomeration, high electron-hole recombination rates, and low degradation efficiency. Herein, we offer a straightforward in situ hydrothermal phase separation strategy for synthesizing ZnIn₂S₄ particles on cellulose/chitosan composite sponges for the effective adsorption and degradation of tetracycline in wastewater. The prepared ZnIn₂S₄ composite sponge displayed a remarkably porous structure (with pore diameters of 150–500 μm), uniformly distributed ZnIn₂S₄ nanoparticles (with diameters of approximately 15 nm), a narrow bandgap (2.88 eV), and exceptional compressibility. Owing to these characteristics and the affinity sites of the polysaccharide sponge skeleton, ZnIn₂S₄ composite sponges represent an innovative model of synergistic adsorption-photocatalytic degradation. The prepared ZnIn₂S₄ composite sponge had a removal efficiency of up to 91.5% for tetracycline under sunlight irradiation and remained effective after eight consecutive cycles. This study highlights the potential application prospects of ZnIn₂S₄ composite sponges in the sustainable and environmentally friendly treatment of antibiotics.

Although lignin is the second most abundant forest biomass polymer, it has been largely neglected in hydrogel electrolytes due to its insolubility and inflexibility. In this study, a double-crosslinked hydrogel was prepared using aspartic acid-modified lignin and sodium alginate, significantly improving the mechanical properties. The hydrogel exhibited an exceptional strain of 3008% and a tensile strength of 0.03 MPa, demonstrating its remarkable mechanical properties. In addition, high ionic conductivity (11.7 mS∙cm^–1) was obtained due to the abundant presence of hydrophilic groups in the hydrogel. The hydrogel-assembled supercapacitor manifested an impressive specific capacitance of 39.46 F∙g^–1. Notably, the supercapacitor showed a wide potential window of 0–1.5 V and achieved a maximum energy density of 5.48 Wh∙kg^–1 at the power density of 499.9 W∙kg^–1. The capacitance retention remained at 115% after 10000 charge-discharge cycles. Finally, the coulombic efficiency was almost 100% during the cycles. Upon reaching a bending angle of 90°, the specific capacitance retention remained impressively high at 94%. These results suggest that the supercapacitor cans maintain normal electrochemical performance under extremely harsh conditions.