Uniform Spherical Structure Research Articles

Efficient recovery of Pd(II) from nuclear wastewater using a functionalized covalent organic frameworks with uniform spherical structure: Size control, performance and mechanism insight

The efficient recovery of palladium from the spent nuclear fuel was of great significance to the sustainable development of nuclear energy. Herein, the uniform spherical COFs were constructed by a facile approach at room temperature, which were further surface functionalized by a thiol-ene “click” reaction to recover Pd(II). Microscopic and spectroscopic studies manifested that the formation mechanism and size of spherical COFs were greatly affected by the amount of catalyst and solvent type. The TAPB-BPTA-DTT and TAPB-BPTA-S-β-CD exhibited high Pd(II) recovery efficiency due to the introduction of sulfhydryl groups, and the maximum adsorption capacities were 489.3 and 234.3 mg/g, respectively. Meanwhile, the water environmental condition played an important role in the separation process, and the classical adsorption models demonstrated that monolayer chemisorption was the dominant removal mechanism. Mechanism analysis showed that the excellent adsorption performance was mainly attributed to the electrostatic interaction, physical absorption and chelation of N, O, and S groups with Pd(II). Thus, it is expected that this work could provide more insight into COFs materials, thereby promoting palladium removal advancements in the spent nuclear fuel.

The oxidized hyaluronic acid hydrogels containing paeoniflorin microspheres regulates the polarization of M1/M2 macrophages to promote wound healing

Controlling excessive inflammation of acute wound is an effective means to shorten the healing time. Therefore, targeted control of the inflammatory response of the wound is a promising therapeutic strategy. In this study, paeoniflorin (Pae) was encapsulated in microspheres and combined with oxidized hyaluronic acid hydrogels to prepare the hydrogel loaded with Pae microspheres (Pae-MPs@OHA) to promote the healing of acute wounds in rats. The results demonstrated that the particle size of the Pae-MPs was 6.84 ± 0.51 μm, and the positive charge was 26.87 ± 1.51 mV. The uniform spherical structure of the Pae-MPs was observed by TEM. The Pae-MPs@OHA can maintain colloidal state in the range of 0.1–3.16 Hz. FTIR suggested that Pae could be effectively wrapped in MPs, and SEM indicated that the Pae-MPs@OHA had a uniform network pore structure. The Pae-MPs@OHA can realize the sustained release of Pae for 96 h. Biocompatibility experiments showed that the Pae-MPs@OHA hydrogels were safe and available. The Pae-MPs@OHA hydrogels can accelerate wound healing in rats. HE and masson staining suggested that the Pae-MPs@OHA could reduce inflammatory cell infiltration, promote re-epithelialization and collagen formation. The Pae-MPs@OHA could decrease the number of M1 and increase the number of M2 in macrophages, thus regulating the release of inflammatory factor TNF-α and IL-1β. The results of molecular docking and western blot results also confirmed that the Pae-MPs@OHA could reduce the expression of NF-κB, pNF-κB, NLRP3, ASC and pro-caspase-1. These findings suggest that the Pae-MPs@OHA has great potential for application in the treatment of inflammatory wound.

Synthesis of Mesoporous Catechin Nanoparticles as Biocompatible Drug-Free Antibacterial Mesoformulation.

While polyphenolic substances stand as excellent antibacterial agents, their antimicrobial properties rely on the auxiliary support of micro-/nanostructures. Despite offering a novel avenue for enhancing polymer performance, controllable fabrication of mesoporous polymeric nanomaterials encounters significant challenges due to intricate intermolecular forces. In this article, mesoporous catechin nanoparticles have been successfully fabricated using a balanced multivariate interaction approach. The harmonization of the water-ethanol ratio and ionic strength effectively balances the forces of hydrogen bonding and π-π stacking, facilitating the controlled assembly of mesostructures. The mesoporous catechin nanoparticles exhibit a uniform spherical structure (∼100 nm), open mesopores with a diameter of ∼15 nm, and a high surface area of ∼106 m2 g-1. While exhibiting a good biocompatibility and negative surface charge, the mesoporous catechins possess outstanding antibacterial ability and function as an antibiotic mesoformulation without the necessity of loading any drugs. This mesoformulation inhibits 50% in vitro Staphylococcus aureus growth with a low concentration of ∼10 μg mL-1 and achieves complete inhibition at ∼25 μg mL-1. In a mouse wound model, accelerated wound healing and complete closure within 6-8 days are achieved. Proteomics of bacteria reveals that the excellent antibacterial property is attributed to the synergetic effect of mesoformulation's mesostructure and the catechin molecule intervening in bacterial metabolism. Overall, this work may pave a novel way for the future exploration of polymer nanomaterials and antibiotic formulations.

Facile synthesis of Ni-doped zeolite-based catalysts from waste coal gasification fine slag for steam reforming of toluene

The preparation of efficient and stable catalysts for biomass tar reforming using low-cost solid waste is of great value for achieving green biomass gasification. In this work, new porous Ni-doped zeolite catalysts were formed by an ion exchange method making use of the waste CGFS as the precursor. At a proper NiO loading content, the catalyst (Na@Air-0.2Ni) exhibits a uniform spherical particle-linked porous structure with NaAlSiO4 as the supporting matrix and NiO particles anchoring on the surface as active sites. The catalytic performance of the catalysts was investigated in toluene reforming experiments to evaluate their potential for biomass tar conversion. Under optimized conditions (720 °C, S/C = 1.5, and N2 flow 25 mL/min), toluene conversion reached 92 % using Na@Air-0.2Ni as a catalyst, yielding 2500 μmol/min CO and 2800 μmol/min H2. Continuous steam reforming of toluene formed to FeNi3 alloy, which in turn strengthens the stability of the catalyst, and a high toluene conversion of 81 % can be achieved in 450 min continuous experiment, indicating the excellent stability of the catalyst. This work has confirmed that coal gasification slag rich in silicon and aluminum has the potential to prepare new zeolite-based catalysts, which is an important exploration for promoting high-value conversion of solid waste.

Doping Ni into CoB achieves surface reconstruction to promote efficient electrocatalytic hydrogen evolution reaction

The effective advancement of skilled transition metal electrocatalysts is crucial for promoting the hydrogen evolution reaction (HER) in the process of water splitting. In this context, the integration of nickel (Ni) transition metal atoms into cobalt boride (CoB) is achieved through an electrochemical deposition approach, yielding a remarkably active electrocatalyst termed Ni@CoB for HER. At 10 mA cm−2, the HER overpotential is 63 mV with a Tafel slope of 64.73 mV dec-1. After 50 h of stability testing, there was no significant current decay observed. By employing material characterization techniques and DFT calculations, it has been shown that the incorporation of Ni leads to a surface reconstruction of CoB, thereby decreasing surface aggregation. The catalyst exhibits a uniform spherical porous structure, facilitating enhanced electron transfer. The doped Ni atoms form a bimetallic synergistic effect with Co atoms, not only increasing the stability of interatomic covalent bonds but also enhancing reaction kinetics. This study illuminates the influence of incorporating transition metal atoms into CoB on the activity of HER, presenting a promising strategy for designing high-performance catalysts for alkaline hydrogen evolution.

Performance of Si3N4 hollow microspheres prepared by spray drying and carbothermal reduction nitridation

A simple and scalable approach to fabricate monodispersed Si3N4 hollow microspheres (Si3N4 HMs) with uniform spherical structures is proposed in this study. This approach involves spray drying of Si3N4 precursor, followed by carbothermal reduction nitridation. The homogeneous Si3N4 precursor was first obtained by mixing phenolic resins and silicon resins, which are carbon and silicon sources, respectively. The spray drying process was then tuned by regulating the viscosity of the precursor by adding polyvinyl butyral in an appropriate ratio. Next, the hollow precursor microspheres were pyrolyzed at 1500 °C for 6 h, while ensuring that the shells of the obtained Si3N4 HMs remained intact. Porous Si3N4 ceramics with different contents of Si3N4 HMs were then prepared using the gel-casting method. It was observed that the densities and dielectric constants of the porous Si3N4 ceramics decreased with an increasing Si3N4 HMs content. Thus, the proposed approach can be used for the synthesis of Si3N4 HMs, that can be further processed into ceramic materials with both low densities and dielectric constants.

Structural and Magnetic Properties of MnxZn1-xFe2O4 Prepared via Sol-Gel Method

Manganese-zinc ferrite MnxZn1-xFe2O4 (MnZnF) powder was prepared using the sol-gel method. The morphological, structural, and magnetic properties of MnZnF powder were studied using X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive X-ray (EDX), field emission-scanning electron microscopes (FE-SEM), and vibrating sample magnetometers (VSM). The XRD results showed that the MnxZn1-xFe2O4 that was formed had a trigonal crystalline structure. AFM results showed that the average diameter of Manganese-Zinc Ferrite is 55.35 nm, indicating that the sample has a nanostructure dimension. The EDX spectrum revealed the presence of transition metals (Mn, Fe, Zn, and O) in Manganese-Zinc Ferrite. The FE-SEM results of MnZnF showed uniform spherical structures. VSM was used to study the change in magnetization, the saturation magnetization, (Ms) value of the samples. The measurement of VSM indicated that the MnZnF exhibits ferromagnetic behavior with coercivity Hc (0.0014 Gauss), remanent magnetization (Mr) (0.202 emu/gr), and saturation magnetization Ms (2.69 emu/g).

Analyzing electrocatalytically accessible sites for hydrogen evolution reaction in rGO doped copper cobalt sulphide

An important, yet difficult problem is the rational design and controlled production of an electrocatalyst for hydrogen evolution reaction (HER) using graphene-based bimetallic sulphide. Here, a novel electrocatalyst for HER was designed and created using a spherical-shaped structure grown on a graphene sheet with a conductive Cu-CoS2 support (rGO@CuCoS2). It takes advantage of the synergistic effect between the copper and cobalt sulphide phases, the naturally low resistance of the bimetal substrate, and the uniform spherical structure. With overpotentials of 84 mV at a current density of 10 mA cm−2 in alkaline electrolytes, the self-supported rGO@CuCoS2 composite catalyst demonstrates outstanding electrocatalytic activity for HER in an alkaline pH range, respectively. The created rGO@CuCoS2 catalyst impressively exhibits steady electrocatalytic activity and high durability in HER processes. The electrocatalytically accessible sites were also discovered to be 15.02 x 1017 sites at a 5 mV s−1 scan rate. This novel mix of methods is intended to offer a workable plan for the advancement of human energy and is promising much beyond the realm of water electrolysis.

Polydopamine modified heteropolyacids catalyst for methacrolein oxidation: Organic ammonia functionalized and regulation of morphology

The oxidation of methacrolein (MAL) to methacrylic acid (MAA) catalyzed by Keggin-type phosphomolybdovanadic acid catalyst belongs to the acid-catalyzed and oxygen-catalyzed co-promoted reactions. It is a challenge to design catalysts with suitable acidity and redox properties. In this paper, a strategy using organic ammonia to modify CsH3PMo11VO40 (CsPAV) was proposed. Core-shell polymerization precursors were synthesized by using polydopamine (PDA) microspheres as modifiers and templates, and regularly arranged PDA-CsPAV bowl-shaped catalysts were obtained via one-step calcination. The morphology, structure, thermal stability, acidity and redox properties of PDA-CsPAV catalysts were characterized by XRD, FT-IR, TG-DTA, XPS, SEM, H2-TPR and NH3-TPD, and the catalytic performance was evaluated by oxidation of MAL to MAA. The rich functional groups on the surface of PDA microspheres combine with H4PMo11VO40 (HPAV) through strong coordination bonds to form a catalyst film. The uniform spherical structure of PDA can adjust the dispersion and morphology of CsPAV. NH4+ was formed and rearranged with heteropoly anions during calcination, which positively regulated the acidity and redox property of the catalyst. The addition of PDA accelerated electron transfer and strengthened the self-reduction process of HPAV. Compared with CsPAV, PDA-CsPAV has more acid sites and oxidation catalytic active centers (VO2+), thus exhibiting better MAL oxidation performance and good thermal stability.

Carrier-Free Gambogic Acid Dimer Self-Assembly Nanomedicines for Rheumatoid Arthritis Treatment.

The insufficient targeting delivery of therapeutic agents greatly impeded the treatment outcomes of rheumatoid arthritis (RA). Despite the recognized therapeutic advantages of gambogic acid (GBA) in inflammatory diseases, its high delivery efficiency to inflammatory site still limits its clinical application. Self-assembly of drug dimers into carrier-free nanoparticles (NPs) has become a straightforward and attractive approach to develop nanomedicines for RA treatment. Herein, homodimers of GBA were designed to form the carrier-free NPs by self-assembly for RA treatment. The synthetic gambogic acid dimers (GBA2) were self-assembled into NPs using a one-step solvent evaporation method. The size distribution, morphology, drug-loading efficiency (DLE) and storage stability were evaluated. A molecular dynamic simulation was conducted to gain further insight into the self-assembly mechanisms of GBA2/NPs. Besides, we investigated the cytotoxicity, apoptosis and cellular uptake profiles of GBA2/NPs in macrophages and osteoclasts. Finally, the specific biodistribution on the ankles of adjuvant-induced arthritis (AIA) mice, and the anti-RA efficacy of the AIA rat model were assessed. GBA2/NPs exhibited the uniform spherical structure, possessing excellent colloidal stability, high self-assembly stability, high drug loading and low hemolytic activity. Comparing with GBA, GBA2/NPs showed higher cytotoxicity, cellular uptake and apoptosis rate against osteoclasts. In addition, GBA2/NPs exhibited much higher accumulation in ankle joints in vivo. As expected, the systematic administration of GBA2/NPs resulted in the greater alleviation of arthritic symptoms, cartilage protection, and inflammation, notably the reduced systemic toxicity compared to free GBA. GBA2/NPs formed GBA dimers exhibited the superior accumulation in the inflamed joint and anti-RA activity, potentially attributing to the similar extravasation through leaky vasculature and subsequent inflammatory cell-mediated sequestration ("ELVIS") effects in inflamed joint and the enhanced cellular uptake in macrophages and osteoclasts. Our findings provide substantial evidence that self-assembly of GBA2/NPs would be a promising therapeutic alternative for RA treatment.

Dual natural antioxidant‐loaded chitosan‐graft‐oleic acid micelles by ultrasound‐assisted self‐assembly: Potential additives for antioxidant active packaging

AbstractNatural antioxidants are beneficial additives for active packaging due to their ability to resist oxidative damage. Polymeric micelles are effective in delivering natural antioxidants in aqueous environments. However, individual encapsulation of a single antioxidant may not be sufficient to meet the needs of modern food packaging. A dual natural antioxidant‐loaded micellar system (i.e., vitamin E [VE] and curcumin [Cur]) was developed to achieve combined functionality and high loading concentration. Chitosan‐graft‐oleic acid (CSOA) micelles were employed as carriers to co‐encapsulate VE and Cur through a facile ultrasound‐assisted self‐assembly method. The prepared VE and Cur co‐loaded micelles (CSOA/VE/Cur) exhibited a uniform spherical structure with an average particle size of 210.6 nm and a zeta potential of +29.5 mV. Moreover, the co‐encapsulation of VE and Cur showed a significant enhancement in both entrapment efficiency, loading capacity and stability as compared to the individual encapsulation of either VE or Cur. In addition, the CSOA/VE/Cur micelles showed improved antioxidant activity than free VE/Cur at the same concentrations, as evidenced by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Moreover, the micellar materials were utilized to fabricate regenerated cellulose (RC) films with antioxidant properties, highlighting their potential as additives for antioxidant active packaging.

Oral liposomes encapsulating ginsenoside compound K for rheumatoid arthritis therapy

Ginsenoside compound K (GCK) can efficiently treat rheumatoid arthritis (RA) due to its immune and anti-inflammatory functions. However, GCK exists some shortcomings such as poor aqueous solubility, low permeability to the intestinal cell membrane, and serious P-gp efflux, thus limiting its application. In order to solve these problems, a folic acid-targeted drug delivery system based on liposomes (FA-LP-GCK) was developed. The prepared FA-LP-GCK had a uniform size distribution and spherical structure, the particle size was 249.13 ± 1.40 nm. Meanwhile, they had high encapsulation efficiency (93.33 ± 0.05 %). FA-LP-GCK also presented good stability in artificial gastric juice, so they can be absorbed into the intestine and enter the blood circulation. The activated RAW 264.7 cells were chosen to evaluate the cytotoxicity and cellular uptake capacity of FA-LP-GCK. FA-LP-GCK showed stronger growth inhibition and cellular uptake ability against activated macrophages. Finally, the efficacy of FA-LP-GCK in vivo was evaluated in the adjuvant arthritis rat model. The results showed that FA-LP-GCK can significantly reduce joint swelling. Furthermore, it can significantly inhibit the expression of pro-inflammatory cytokines and improve synovial hyperplasia of joints and pathological changes in the spleen. Therefore, FA-LP-GCK may be a potential therapeutic approach for RA.

One-pot synthesis of a poly(styrene-acrylic acid) copolymer-modified silica stationary phase and its applications in mixed-mode liquid chromatography

As modified ligands with a wide range of sources, abundant functional groups, and good biocompatibility, polymers have been widely used in the development of silica-based chromatographic stationary phases. In this study, a poly(styrene-acrylic acid) copolymer-modified silica stationary phase (SiO2@P(St-b-AA)) was prepared via one-pot free-radical polymerization. In this stationary phase, styrene and acrylic acid were used as functional repeating units for polymerization and vinyltrimethoxylsilane (VTMS) was used as a silane coupling agent to link the copolymer and silica. Various characterization methods, such as Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), N2 adsorption-desorption analysis, and Zeta potential analysis, confirmed the successful preparation of the SiO2@P(St-b-AA) stationary phase, which had a well-maintained uniform spherical and mesoporous structure. The retention mechanisms and separation performance of the SiO2@P(St-b-AA) stationary phase in multiple separation modes were then evaluated. Hydrophobic and hydrophilic analytes as well as ionic compounds were selected as probes for different separation modes, and changes in the retention of the analytes under various chromatographic conditions, including different methanol or acetonitrile contents and buffer pH values, were investigated. In reversed-phase liquid chromatography (RPLC) mode, the retention factors of alkyl benzenes and polycyclic aromatic hydrocarbons (PAHs) on the stationary phase decreased with increasing methanol content in the mobile phase. This finding could be attributed to the hydrophobic and π-π interactions between the benzene ring and analytes. The retention changes of alkyl benzenes and PAHs revealed that the SiO2@P(St-b-AA) stationary phase, similar to the C18 stationary phase, exhibited a typical reversed-phase retention behavior. In hydrophilic interaction liquid chromatography (HILIC) mode, as the acetonitrile content increased, the retention factors of hydrophilic analytes gradually increased, and a typical hydrophilic interaction retention mechanism was inferred. In addition to hydrophilic interaction, the stationary phase also demonstrated hydrogen-bonding and electrostatic interactions with the analytes. Compared with the C18 and Amide stationary phases prepared by our groups, the SiO2@P(St-b-AA) stationary phase exhibited excellent separation performance for the model analytes in the RPLC and HILIC modes. Owing to the presence of charged carboxylic acid groups in the SiO2@P(St-b-AA) stationary phase, exploring its retention mechanism in ionic exchange chromatography (IEC) mode is of great importance. The effect of the mobile phase pH on the retention time of organic bases and acids was further studied to explore the electrostatic interaction between the stationary phase and charged analytes. The results revealed that the stationary phase has weak cation exchange ability toward organic bases and electrostatically repels organic acids. Moreover, the retention of organic bases and acids on the stationary phase was influenced by the analyte structure and mobile phase. Thus, the SiO2@P(St-b-AA) stationary phase could provide multiple interactions, as demonstrated by the separation modes described above. The SiO2@P(St-b-AA) stationary phase showed excellent performance and reproducibility in the separation of mixed samples with different polar components, indicating that it has promising application potential in mixed-mode liquid chromatography. Further investigation of the proposed method confirmed its repeatability and stability. In summary, this study not only described a novel stationary phase that could be used in RPLC, HILIC, and IEC modes but also presented a facile "one-pot" preparation approach that could provide a new route for the development of novel polymer-modified silica stationary phases.

Effects of multi-frequency ultrasound on sodium caseinate/pectin complex: Emulsifying properties, interaction force, structure and correlation

This study aimed to improve the emulsification properties of the sodium caseinate (Cas) and pectin (Pec) complex using multi-frequency power ultrasound to regulate the complexation of Cas and Pec. The results revealed that optimal ultrasonic treatment (Frequency 60 kHz, power density 50 W/L, and time 25 min) led to a 33.12 % increase in emulsifying activity (EAI) and a 7.27 % increase in emulsifying stability index (ESI) of the Cas-Pec complex. Our results demonstrated that electrostatic interactions and hydrogen bonds were the main driving forces for complex formation, and these were reinforced by ultrasound treatment. Moreover, it was observed that ultrasonic treatment improved the surface hydrophobicity, thermal stability, and secondary structure of the complex. Scanning electron microscopy and atomic force microscopy analyses revealed that the ultrasonically prepared Cas-Pec complex had a dense, uniform spherical structure with reduced surface roughness. It was further confirmed that the complex's emulsification properties were highly correlated with its physicochemical and structural properties. Multi-frequency ultrasound changes the interaction by regulating protein structure and ultimately acting on the interfacial adsorption behavior of the complex. This work contributes to expanding the role of multi-frequency ultrasound in modifying the emulsification properties of the complex.

Fabrication of antireflective coatings on cotton surface using dye-loaded nanoparticles for eco-friendly textile inkjet printing

Colored cellulose textiles extensively enriched human-beings' modern lives, but the problem of dye pollution has been a long-plagued trouble and still poses an alarming threat to environment and human beings. In view of this problem, herein, multi-color antireflective nanoparticles inspired by biology were prepared using dye adsorption method. Then, it was applied in cotton inkjet printing to realize the improvement of dye utilization efficiency. Results shows that, cationic poly(styrene-butyl acrylate-vinylbenzyl trimethylammonium chloride) (PSBV) nanoparticles exhibited high dye capacity. The dye-adsorbed nanoparticles possessed uniform spherical structure with an average size at about 90 nm and a surface potential over −30 mV. Turbiscan Lab measurement and high-speed camera system show that the dye-adsorbed nanoparticles possessed good stability and satisfactory jetting performance. Moreover, after the inkjet printing on cotton fabrics, the reflectance was significantly reduced with higher color strength in comparison to the same concentration of dye solution. Moreover, owing to the reaction between the nanoparticles and -OH groups on cotton fibers, durable patterns were obtained. This work provides a potential method on the preparation and application of dye/polymer nanoparticles in textile coloration for improved cleanliness and efficiency.

Bioactive wound dressing based on decellularized tendon and GelMA with incorporation of PDA-loaded asiaticoside nanoparticles for scarless wound healing

In this study, bioactive composite hydrogels were created using the decellularized extracellular matrix (ECM), GelMA, and Polydopamine-loaded Asiaticoside (AC@PDA) nanoparticles for use as wound dressings that could promote healing. A decellularization method was used to obtain ECM from porcine Achilles tendon tissue. AC@PDA nanoparticles were then synthesized and found to have a uniform spherical structure with good cytocompatibility, particularly when compared to PDA nanoparticles alone. The mechanical properties of the bioactive composite hydrogels showed good elasticity and shape recovery after compression, with a slight decrease in compressive strength due to the addition of nanoparticles. The formation of interpenetrating networks through the use of EDC/NHS was also found to improve the mechanical properties and moisture retention of the hydrogels. The PDA/ECM-G and AC@PDA/ECM-G hydrogels showed higher water absorption capacity and similar moist retention capacity to the ECM-G hydrogel. The microstructure of the hydrogels was observed through SEM, with the ECM-G hydrogel showing a dense and compact structure, while the PDA/ECM-G and AC@PDA/ECM-G hydrogels displayed a more porous and interconnected structure due to the presence of nanoparticles. In vitro cytotoxicity tests on human skin fibroblasts showed good biocompatibility for all hydrogels. The in vivo wound healing performance of the hydrogels was also tested on a full-thickness excisional wound model in mice, with the AC@PDA/ECM-G hydrogel showing the fastest wound closure without scarring and the highest-formed hair follicles. The AC@PDA/ECM-G hydrogel had the best performance in promoting wound healing. These results suggest that the bioactive hydrogel has the potential for use as a wound dressing.

Highly boosted photocatalytic H2 production from ZnS particles assisted by Cd-Cu co-doping

Cd-Cu co-doping was applied to improve photocatalytic H2 evolution efficiency of the ZnS photocatalyst. This study confirms that an optimal Cd-Cu dopant ratio enhances the photocatalytic activity by improving light absorbance and minimizing charge recombination. Furthermore, the optimum Cd-Cu ratio plays a significant role in inducing a uniform spherical morphology and CdS-CuS crystalline structure. The drawbacks of the ZnS photocatalysts can be overcome by reducing the band gap with an increased charge carrier concentration. In the type-II heterojunction system of the best C2C5 (Cd:Cu = 2:5) photocatalyst sample, electrons are effectively transferred through hierarchical band alignment while blocking the separated holes to reduce charge recombination. The content-optimized C2C5 sample greatly accelerated the charge transfers during the photocatalytic reactions. Thus, ZnS photocatalyst assisted by Cd-Cu co-doping is a promising material for overpowering the inherent problems of the metal sulfides for solar hydrogen productions.

Decanoic acid-palmitic acid/SiO2@TiO2 phase change microcapsules based on RBF model with excellent photocatalysis performance and humidity control property.

The decanoic acid-palmitic acid composite phase change material compounds with SiO2 and TiO2 to prepare decanoic acid-palmitic acid/SiO2@TiO2 phase change microcapsules (D-P-SiO2@TiO2 PCM). The D-P-SiO2@TiO2 PCM could show efficient temperature regulation, remove pollutants through photocatalysis, and control air humidity. However, it is difficult to obtain the best experimental scheme directly using the traditional experimental setup due to the complicated photocatalytic-humidity performance. The radial basis function (RBF) model optimized the uniform experimental design parameters, and the D-P-SiO2@TiO2 PCM showed enhanced photocatalytic-humidity performance. The RBF-calculated preparation parameters were as follows: the molar ratio of decanoic acid-palmitic acid to tetraethyl silicate was 0.42, pH was 1.83, the molar ratio of deionized water to tetraethyl silicate was 98.15, while the molar rate of tetrabutyl titanate to tetraethyl silicate was 0.76. The degradation rate of gaseous formaldehyde by the RBF-optimized D-P-SiO2@TiO2 PCM was 69.57% after 6h, and the moisture content was between 0.0923 and 0.0940g·g-1 at 43.16-75.29% relative humidity (RH). The comparison between model optimization and the experiment sample prepared using the optimized parameters showed that the theoretical photocatalytic-humidity performance target value was 2.0502, and the tested target value was 2.0757. The error calculated from these two values was only 1.24%, and both were better than the best value of uniform experimental calculation. RBF mathematical model was proved to be an effective, convenient, and economic-saving method to simulate and predict D-P-SiO2@TiO2 PCM experimental design parameters. SEM and TEM analyses of the RBF-optimized D-P-SiO2@TiO2 PCM showed a uniform spherical structure, and the particle size analysis analyses was about 200nm. The DSC analysis showed the phase transition temperature range was between 16.97 and 28.94°C, within the comfort range of the human body. The UV-Vis investigations showed the absorption edge of the RBF-optimized D-P-SiO2@TiO2 PCM was 380nm, in line with the band gap structure of the TiO2 anatase phase. The thermogravimetric investigations showed that this composite was stable at normal temperature and pressure. After a 100 times hot-cold cycle, the quality of the RBF-optimized D-P-SiO2@TiO2 PCM maintained its stability, as the photocatalytic-humidity performance was almost the same. The N2-adsorption analysis showed it had a high specific surface area and irregular pore structures, which could help it regulate air humidity. Considering these results, the D-P-SiO2@TiO2 PCM, a new ecological functional material, would be used in the construction industry to improve the architectural ecological environment.

Fabrication of highly crystalline covalent organic framework for solid-phase extraction of three dyes from food and water samples.

Herein, a covalent organic framework, which was fabricated at room temperature by using 1,3,5-tris(p-formylphenyl) benzene and 1,3,5-tris(4-aminophenyl)benzene as building blocks, was employed as an adsorbent for solid-phase extraction of dyes including congo red, methyl blue and direct red 80 for the first time. The prepared covalent organic framework was properly characterized by different techniques and the results revealed that it had a uniform spherical structure, high crystallinity, satisfactory surface area, and good thermal stability. Moreover, the adsorption performance of the material was explored by using static and dynamic adsorption experiments and the results indicated that the material showed good adsorption capacities for three dyes with adsorption capacities in the range of 55.25-284.10mg/g and the adsorption equilibrium can be achieved in 15min. Further, to achieve the best adsorption effects of the material, the influence parameters such as pH, ionic strength, type of desorption solvent, and the material dosage in the solid-phase extraction column, were optimized in turn. Finally, under optimal conditions, the solid-phase extraction coupled with HPLC was applied to the analysis of dyes in food and water samples. The recoveries of dyes in actual samples were satisfactory, revealing the unique applicability of the material in the sample pretreatment field.

One-Step Phase Separation for Core-Shell Carbon@Indium Oxide@Bismuth Microspheres with Enhanced Activity for CO2 Electroreduction to Formate.

It is a substantial challenge to construct electrocatalysts with high activity, good selectivity, and long-term stability for electrocatalytic reduction of carbon dioxide to formic acid. Herein, bismuth and indium species are innovatively integrated into a uniform heterogeneous spherical structure by a neoteric quasi-microemulsion method, and a novel C@In2 O3 @Bi50 core-shell structure is constructed through a subsequent one-step phase separation strategy due to melting point difference and Kirkendall effect with the nano-limiting effect of the carbon structure. This core-shell C@In2 O3 @Bi50 catalyst can selectively reduce CO2 to formate with high selectivity (≈90% faradaic efficiency), large partial current density (24.53 mA cm-2 at -1.36V), and long-term stability (up to 14.5h), superior to most of the Bi-based catalysts. The hybrid Bi/In2 O3 interfaces of core-shell C@In2 O3 @Bi will stabilize the key intermediate HCOO* and suppress CO poisoning, benefiting the CO2 RR selectivity and stability, while the internal cavity of core-shell structure will improve the reaction kinetics because of the large specific surface area and the enhancement of ion shuttle and electron transfer. Furthermore, the nano-limited domain effect of outmost carbon prevent active components from oxidation and agglomeration, helpful for stabilizing the catalyst. This work offers valuable insights into core-shell structure engineering to promote practical CO2 conversion technology.