Journal of Colloid and Interface Science最新文献

Covalent organic frameworks (COFs) have shown great potential in the photocatalytic production of hydrogen peroxide (H₂O₂) due to their precisely designed and customized ability. Nevertheless, the quest for efficient overall photosynthesis of H₂O₂ in pure water without sacrificial agents using COF photocatalysts remains a formidable challenge. Herein, three pyrene-based covalent organic frameworks are synthesized using an advanced interfacial design strategy. By incorporating functional groups of F, H, and OH into a COF skeleton, their wettability and charge-separation properties are fine-tuned. These COFs show great performances as photocatalysts for H₂O₂ production from water and air by utilizing both the oxygen reduction reaction and water oxidation reaction pathways. Compared to PyCOF-F and PyCOF-H, PyCOF-OH demonstrates superior H₂O₂ production efficiency due to its improved hydrophilicity and enhanced carrier separation, achieving a remarkable rate of 2961 µmol g^-1 h^-1 from 25 mL pure water and air. Further, the mechanism of H₂O₂ production over PyCOF-OH is clarified by combining a series of control experiments, in situ characterizations, and theoretical calculations. This study offers valuable insights into the interfacial design of high-performance photocatalysts for H₂O₂ synthesis.

Indoor air pollution, predominantly caused by volatile organic compounds (VOCs), poses significant health hazards when concentrations surpass critical thresholds. Using waste corn straw as carbon source and urea as nitrogen source, straw derived carbon aerogel (CAGH) loaded with g-C₃N_{4H2O-N2-450-3 h} was successfully prepared by hydrothermal and water-assisted calcination. Following water-assisted regulation, g-C₃N_{4H2O-N2-450-3 h} on CAGH exhibited a mixed structure comprising honeycomb and two-dimensional filaments, while the growth of g-C₃N_{4H2O-N2-450-3 h} was uniformly distributed on carbon aerogel in a line-surface combination fashion. This innovative binding method not only enhanced the loading capacity of g-C₃N₄ and the mechanical elasticity of aerogel, but also exposed a large number of adsorption sites, resulting in a significant increase in its adsorption capacity for VOCs, exceeding that of commercial activated carbon (AC). In comparison to pure g-C₃N₄, CAGH exhibited an expanded photo-response range. Under the exposure of visible light, CAGH proved highly effective in eliminating 73.87 % of toluene. In addition, it has demonstrated efficient removal of formaldehyde and acetone VOCs with good cyclic stability. Therefore, this work aims to reduce the emission of pollutants at source and provide an effective and economical strategy for the preparation of clean building materials from renewable materials, with potential applications in the environmental field.

Hydroxychloroquine sulfate (HCQ) is extensively utilized due to its numerous therapeutic effects. Because of its properties of high solubility, persistence, bioaccumulation, and biotoxicity, HCQ can potentially affect water bodies and human health. In this study, the LaCo_0.95Mo_0.05O₃-CeO₂ material was successfully prepared by the sol-gel process, and it was applied to the experiment of degrading HCQ by activating peroxymonosulfate (PMS). The results of characterization analysis showed that LaCo_0.95Mo_0.05O₃-CeO₂ material had good stability, and the problem of particle agglomeration had been solved to some extent. Compared with LaCo_0.95Mo_0.05O₃ material, it had a larger specific surface area and more oxygen vacancies, which was helpful to improve the catalytic activity for PMS. Under optimal conditions, the LaCo_0.95Mo_0.05O₃-CeO₂/PMS system degraded 95.5 % of HCQ in 10 min. The singlet oxygen, superoxide radicals, and sulfate radicals were the main radicals for HCQ degradation. The addition of Mo⁶⁺/Mo⁴⁺ and Ce⁴⁺/Ce³⁺ promoted the redox cycle of Co³⁺/Co²⁺ and enhanced the degradation rate of HCQ. Based on density functional theory and experimental analysis, three HCQ degradation pathways were proposed. The analysis of T.E.S.T software showed that the toxicity of HCQ was obviously reduced after degradation. The LaCo_0.95Mo_0.05O₃-CeO₂/PMS system displayed excellent reusability and the ability to remove pollutants in a wide range of real-world aqueous environments, with the ability to treat a wide range of pharmaceutical wastewater. In summary, this study provides some ideas for developing heterogeneous catalysts for advanced oxidation systems and provide an efficient, simple, and low-cost method for treating pharmaceutical wastewater that has good practical application potential.

Challenges associated with lithium dendrite growth and the formation of dead lithium significantly limit the achievable energy density of lithium metal batteries (LMBs), particularly under high operating current densities. Our innovative design employs a state-of-the-art 2500 separator featuring a meticulously engineered cellulose acetate (CA) coating (CA@2500) to suppress dendrite nucleation and propagation. The CO functional groups in CA enhances charge transfer kinetics and triggering the decomposition of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), which leads to the formation of a more robust solid electrolyte interphase (SEI) composed primarily of LiF. Moreover, the introduction of polar functional groups in the CA enhances the separator's hydrophilic properties, facilitating the uniform Li⁺ flux and creating a conductive pathway for efficient lithium migration. As a result, the CA@2500 separator exhibits a high lithium-ion transfer number (0.88) and conductivity. The lithium symmetric cell assembles with the CA@2500 separator displays a stable cycling performance over 5500 h at a current density and capacity of 10 mA cm^-2 and 10 mAh cm^-2, respectively. Additionally, LPF battery with CA@2500 separator shows an excellent capacity retention at 0.2 C with an average decay of 0.055 % per cycle. Moreover, a high capacity of 105 mAh g^-1 is maintained after 500 cycles at 5 C with an average decay of only 0.027 % per cycle. This work achieved high stability of LMBs through simplified engineering.

Designing inexpensive, high-efficiency and durable bifunctional catalysts for urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) is an encouraging tactic to produce hydrogen with reduced energy expenditure. Herein, oxygen vacancy-rich cobalt hydroxide/aluminum oxyhydroxide heterostructure on nickel foam (denoted as Co(OH)₂/AlOOH/NF-100) has been fabricated using one step hydrothermal process. Theoretical calculation and experimental results indicate the electrons transfer from Co(OH)₂ to highly active AlOOH results in the interfacial charge redistribution and optimization of electronic structure. Abundant oxygen vacancies in the heterostructure could improve the conductivity and simultaneously serve as the active sites for catalytic reaction. Consequently, the optimal Co(OH)₂/AlOOH/NF-100 demonstrates excellent electrocatalytic performance for HER (62.9 mV@10 mA cm^-2) and UOR (1.36 V@10 mA cm^-2) due to the synergy between heterointerface and oxygen vacancies. Additionally, the in situ electrochemical impedance spectrum (EIS) for UOR suggests that the heterostructured catalyst exhibits rapid reaction kinetics, mass transfer and current response. Importantly, the urea-assisted electrolysis composed of the Co(OH)₂/AlOOH/NF-100 manifests a low cell voltage (1.48 V @ 10 mA cm^-2) in 1 M KOH containing 0.5 M urea. This work presents a promising avenue to the development of HER/UOR bifunctional electrocatalysts.

The practical applications of lithium sulfur batteries (LSBs) are hindered by notorious shuttle effect and sluggish conversion kinetics of intermediate polysulfides. Herein, Mo₂C-Co heterogeneous particles decorated two-dimensional (2D) carbon nanosheets grown on hollow carbon microtubes (CCC@MCC) are synthesized. Three-dimensional (3D) carbon framework with Mo₂C-Co heterogeneous particles combines the conductivity, adsorption and catalysis, effectively trapping and accelerating the conversion of polysulfides. As evidenced experimentally, the hetero-structured Mo₂C-Co with high Li⁺ diffusion coefficient enables uniform precipitation and complete oxidation of Li₂S. Meanwhile, CCC@MCC is found to have multiple application possibilities for lithium-sulfur batteries. As an interlayer, the cells deliver an excellent capacity of 881.1 mAh/g at 2C and still retain 438.2 mAh/g after 500 cycles under the low temperature of 0 ℃. As a sulfur carrier, the cell with a sulfur loading of 7.0 mg cm^-2 exhibits a high area capacity of 5.3 mAh cm^-2. This work provides an effective strategy to prepare heterostructured material and imaginatively exploit the application potential of it.

The promising non-noble electrocatalyst with well-defined structure is significant for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) for the renewable energy devices like zinc-air batteries (ZABs). Herein, the four phenyl-linked cobaltporphyrin-based covalent organic polymers (COPs-1-4) with the different edge substituents (1 = -tBu, 2 = -Me, 3 = -F, and 4 = -CF₃) are firstly designed and synthesized via a simple, efficient one-pot method. With the increase of electron donating capacity of the substituents, the highest occupied molecular orbital energy (E_HOMO) gradually increases in the order of COP-4 < COP-3 < COP-2 < COP-1. Consequently, the optimal COP-1 with -tBu edge groups exhibits the highest half-wave potential (E_1/2) of 0.84 V (vs. RHE) among the four COPs, which is comparable with commercial Pt/C in alkaline media. The DFT calculations further reveal that with strong electron donating capacity, the Gibbs free energy decreases in the order of COP-4 > COP-3 > COP-2 > COP-1 by modulating the adsorption energy of OOH* at rate-determining step (RDS) to promote ORR activity. Furthermore, introducing Ni (II) and Co (II) into porphyrin centers afford the bimetallic CoNi-COP-1 with both Co-N₄, Ni-N₄ active sites and edge substituted -tBu. The synergistic effect of Co, Ni bimetallic active sites and strong electron-donating -tBu substituents renders the CoNi-COP-1 the highest HOMO and smallest energy gap between the E_LUMO and E_F among the as-prepared five COPs, which leads to more filling electrons of its LUMO level, and thus exhibits the excellent ORR and OER bifunctional catalytic activities with an E_1/2 as high as 0.85 V and an overpotential (η) of 0.34 V at 10 mA cm^-2 in alkaline media, superior to monometallic Co-containing COPs-1-4. In particular, the assembled ZABs with bifunctional catalyst CoNi-COP-1 possesses high power density (94.10 mW cm^-2), high specific capacity (841.71 mAh g_Zn^-1) and long durability of over 160,000 s. This work exemplifies the rational design of pyrolysis-free non-noble metal COP-based electrocatalyst through optimizing the intrinsic metal center and its secondary coordination environment.

Titanium dioxide (TiO₂) is a kind of generally used photocatalyst with the assistance of UV light. To utilize the visible light and save the energy, herein, a titanium (Ti)-based nanocomposite, i.e. PPDs/C-hTiO₂, was designed and prepared based on carbon (C)-doping and photosensitive polymer dots (PPDs) nano-hybridization. This design synergistically narrowed the band gap energy (E_g) and strengthened absorption of the visible light. As a result, PPDs/C-hTiO₂ exerted remarkably high catalytic ability under visible light, surpassing that of commercial TiO₂ (i.e. P25) under UV light. PPDs/C-hTiO₂ succeeded in assisting the degradation of sulindac with a degradation efficiency of 96.7%±1.25% within 10 min under visible light. The degradation process was driven by the generation of hydroxyl radical, superoxide radical and holes, and the total biotoxicity of degradation products was decreased compared to the parent compound. This study creatively combined the C-doping and PPDs nano-hybridization to construct a visible light Ti-based photocatalyst, proposing a potential technique for addressing current aquatic environmental issues.

Reducing the size of catalysts and tuning their electronic structure and interfacial properties are key to enhancing catalytic performance. Herein, a series of quantum-sized Co-based nanodot composites, including Co₃O₄/C, CoS₂/C, CoN/C, and CoP/C, were synthesized using chemical vapor deposition (CVD) methods. By means of experimental measurement and theoretical calculation, CoP/C exhibited more robust electrochemical response than other Co-based compounds in electrochemical oxidation of N₂H₄ (HzOR) and hydrogen evolution reaction (HER). The catalytic activities of CoP/C can be further enhanced by introducing Co vacancies on the surface of CoP/C (labeled as Co_1-xP/C). The results demonstrated that Co_1-xP/C not only exhibited notable electrochemical responses at an ultra-low N₂H₄ concentration of 0.67 μM, showcasing its potential for ultra-sensitive N₂H₄ detection but also realized HzOR instead of the oxygen evolution reaction (OER) half-reaction, thereby lowering the overpotential to 2.0 mV at 10.0 mA cm^-2. Finally, a Zn-hydrazine (Zn-Hz) battery was fabricated as a promising energy conversion device, showing the exceptional practical value of Co_1-xP/C.

A new type of pH-sensitive hydrogel containing supramolecular structures was fabricated from maleimide-functionalized polyrotaxane, ɛ-polylysine and furan-functionalized hyaluronic acid by Diels-Alder reaction and amino-maleimide reaction. Firstly, pseudo polyrotaxane was obtained through self-assembly of polyethylene glycol and α-cyclodextrin, and then capped with 1-adamantanecarboxylic acid to convert it into polyrotaxane. Secondly, a maleimide-functionalized slidable crosslinker was obtained by modifying the polyrotaxane with 3-maleimide propionic acid, and furan-functionalized hyaluronic acid was prepared by modifying it with 2-furanmethylamine. Thirdly, the hydrogel cotaining supramolecular structures was fabricated from the prepared slidable crosslinker, ɛ-polylysine, and furan-functionalized hyaluronic acid in mixed solvent of water and N,N-dimethylformamide. Taking gel mass fraction and swelling ratio as two indicators, the formation parameters of hydrogel were optimized through single- factor experiments. The pH-sensitivity, rheological properties, self-healing performance, and degradation behavior of the hydrogel were investigated. Cytotoxicity assay, live/dead stains, and hemolysis assay were done to verify the biocompatibility of the hydrogel. Finally, the slow-release behavior of the hydrogel containing lidocaine hydrochloride was studied. The hydrogel possesses good biocompatibility, pH-sensitivity, self-healing behavior, degradation, and drug-controlled release, and can find broad application in biomaterials.