Here, we report the formation of highly-stable and homogenous perovskite-based luminescent films with honeycomb-patterned surfaces by using the breath-figure method. The optimized PGPO@CsPbBr3 film exhibited uniform honeycomb-patterned pores that endowed it with uniform luminescence, high stability, and hydrophobicity. This work provides a new approach for fabricating highly-stable and homogenous perovskite-based luminescent films for full-color backlight displays.
Oligomerization presents a wide range of opportunities for transforming light olefins into liquid fuels. This study centers on a novel catalyst system – phosphotungstic acid (PW) loaded onto MCM-41 prepared via impregnation, aiming to tackle these challenges. The ordered mesoporous structure, high surface area, and facile recovery of MCM-41 make it an ideal support for PW. Under the mild reaction conditions of 70 °C, 1 MPa, and 5 h, the 20% PW/MCM-41 catalyst exhibited remarkable catalytic performance, achieving an isopentene conversion rate of 77.8%, a selectivity of 93.5% towards the C10 dimer product, and a yield of 72.7%. Encouragingly, the catalyst could be reused without special treatment, maintaining a selectivity above 93% for the C10 dimer product over five cycles, showcasing outstanding stability and regeneration capability. This research not only provides robust insights into catalyst design for isopentene dimerization but also paves the way for sustainable advancements in industrial catalysis.
Single-atom catalysts (SACs) based on metal–nitrogen–carbon (M–N–C) compounds have been identified as a potential substitute for Pt-based oxygen reduction reaction (ORR) catalysts due to their facile availability and low cost. M1M2–N–C based dual-atom catalysts (DACs) may be utilised to regulate the active site and optimise their ORR activity. Accordingly, M1M2–N6–C14 (M1 = Mn, Fe, Co; M2 = late transition metals) DACs were constructed within a graphene slab. M1M2–N–C is more stable than the corresponding M1–N–C and M2–N–C due to the affinity between M1 and M2. Furthermore, the ORR activity of FeM–N–C (M = late transition metals), MnM–N–C (Co, Ru, Rh, Os, Ir, and Re) and CoM–N–C (M = Cu, Zn, Pd, and Pt) is enhanced in comparison to that of Fe–N–C, due to the modified electronic properties. In comparison to other active ORR electrocatalysts, FeCu–N–C is positioned at a relatively high level on the volcano plot. To gain further insight into the dynamic stability of FeCu–N–C under working conditions (*OOH, 80 °C), an ab initio molecular dynamics simulation was employed. The accelerated structural evolution of the FeCu–N–C electrocatalyst resulted in the Cu atom being pulled out of the N–C substrate plane. Nevertheless, the resulting Fe(vacancy)–N–C and Fe(vacancy)–NH–C electrocatalysts have been observed to retain high ORR activity and stability. The findings of this study have significant implications for the design of DACs.
Janus particles are a class of materials that exhibit both surface morphology and chemical properties with asymmetry. However, at present, precise control over the structure and composition of Janus particles still faces numerous challenges. Conventional seed emulsion polymerization methods require heating to induce phase separation after seed swelling, leading to extended reaction periods. In light of this, we propose a novel photo-induced seed swelling polymerization approach. This method employs non-crosslinked polyglycerol methacrylate (poly(GMA)) as seed particles, utilizing 4-vinylpyridine (4-VP) as the functional monomer and divinylbenzene (DVB) as the cross-linker. The aqueous phase consists of polyvinyl alcohol (PVA) and sodium dodecyl sulfate (SDS), with 2,2-dimethoxy-2-phenylacetophenone (DMPA) as the photo-initiator. By adjusting parameters such as seed quantity, type of porogen, and porogen volume ratio, diverse morphologies including octopus-like, jellyfish-like, snowman-like, and half raspberry-like Janus particles are successfully synthesized. Subsequently, Janus carbon particles are obtained through calcination and employed as anode materials in lithium-ion batteries. The electrochemical performance of Janus carbon particles is assessed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), rate capability tests, constant current charge–discharge measurements, and cycling performance evaluation. These tests indicate the excellent electrochemical properties of the material. Our research provides a valuable strategy for creating Janus carbon particles with controlled morphologies.
α-Glucosidase inhibitors seem to be most effective in the treatment of diabetes. β-Lactams have been reported to have some antidiabetic properties with α-glucosidase inhibitory activity. The current study aims to evaluate the potential of newly synthesized β-lactams B8–B14 as α-glucosidase inhibitors that can help to control high blood glucose levels in type 2 diabetes mellitus. The synthesized 3-nitrophenyl imine derivatives (1 eq.) reacted with ethenone (1 eq.) in benzene by a Staudinger cycloaddition reaction to afford β-lactams B8–B14, which was confirmed by advanced spectroscopic techniques and elemental analysis. The antihyperglycemic studies revealed that compounds B8, B9 and B12–B14 at a dosage of 5 mg kg−1 and after 24 h of administration showed a higher percentage decrease in blood sugar (12.61–21.07%) than the reference drug glibenclamide (11.74%). In line with in vitro studies, β-lactams B8 and B9 proved to be potent inhibitors of α-glucosidase enzyme with IC50 values 3.33 μM and 2.21 μM, respectively, higher than the standard drug acarbose (IC50 = 5.47 μM). Further, in vivo experiments confirmed that the most potent antidiabetic agents B8 and B9 significantly decrease the ALT level (71.1–74.3%) to prevent liver injury induced by diabetes. The higher antioxidant potential confirmed the role of B9 as a lead antidiabetic agent to manage the ROS generated by diabetes. AutoDock Vina was used to identify the catalytic sites of α-glucosidase and to remove water molecules and add hydrogen and Kollman charges to the protein structure. In molecular docking studies, B9 fits tightly within the catalytic pocket of the α-glucosidase enzyme with a binding affinity of −9.1 kcal mol−1, supporting its potential as a strong α-glucosidase inhibitor. The most potent compound, B9, was found to have optimal lipophilicity (2.63), the highest drug-likeness (86.9%) and excellent gastrointestinal absorption that are suitable for bioavailability and drug design. Moreover, these physiochemical properties also showed excellent correlation with the α-glucosidase inhibitory and antidiabetic activity. Overall, these excellent results suggest that the most potent compound, B9, has the potential to develop as a therapeutic drug in the future to treat diabetes with α-glucosidase inhibitory activity.
The development of highly active and stable iron–nitrogen (Fe–Nx) based oxygen reduction reaction (ORR) catalysts with pH versatility is one of the future directions of electrochemical energy. However, the task of designing and controlling the three-dimensional local structure of Fe species to obtain high ORR activity and stability remains a challenge. In this study, we prepared hierarchical porous FeN–hcC (iron–nitrogen–highly curved carbon) catalysts derived from ZIF-L by a soft template method. The highly curved carbon surface possibly results in a compressive strain effect on the supported Fe–Nx active site, which can not only enhance the high exposure of the active site to improve the electrocatalytic activity, but also facilitate the stability of the Fe–Nx site during the ORR catalytic process. FeN–hcC-1 exhibited a high half-wave potential of 0.89, 0.77 and 0.82 V vs. RHE in alkaline, acidic, and neutral media, respectively. In addition, after cyclic durability tests in different electrolyte environments, good stability is still maintained, which is significantly better than the planar Fe–Nx site and Pt/C catalyst. This work provides a new synthetic strategy for the construction of highly curved surfaces of carbon materials, while inspiring a method to improve the ORR performance of ZIF-derived materials.
A series of sulfonated carbon acid catalysts with strong acidity was prepared by simultaneous carbonization and sulfonation of biomass sucrose in the presence of the organic sulfonating agent sulfosalicylic acid under hydrothermal conditions at temperatures ranging from 150 to 200 °C. It was found from FTIR and XPS spectra that the surface of carbon was efficiently functionalized with –SO3H groups. Research on the mechanism of the sulfonation process indicated that the intermediate 5-hydroxymethyl furfural (5-HMF), which was easily hydrolyzed from sucrose, was prone to carbonization and functionalized with –SO3H groups simultaneously. Compared with 5-HMF and fructose used as the initial carbon precursor, the slow hydrolysis of sucrose to intermediate 5-HMF to suppress its rapid carbonization is favorable for the efficient grafting of –SO3H groups when sucrose is used as the initial carbon precursor. The prepared sulfonated carbons were evaluated as acid catalysts in a typical ester hydrolysis reaction, namely, hydrolysis of ethyl acetate. The sulfonic acid groups were identified to be the active sites and quantified by a cation-exchange process. The activity of the sulfonated carbon was primarily correlated with the total number of active sites. However, when the total number of the –SO3H groups did not change, higher activities were shown on the sulfonated carbon with higher surface S content.
Novel ordered β-ketoimine-palladium(II) multilayers supported on the surface of a silicon wafer (Si@[β-Ki-Pd][L2-Pd]n, n = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11) were fabricated using layer-by-layer (LbL) self-assembly and characterized using Raman spectroscopy (RS), ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Their catalytic properties were systematically investigated using the Suzuki–Miyaura cross-coupling reaction as a template. Among these catalytic multilayers, Si@[β-Ki-Pd][L2-Pd]11 exhibited high activity (TOF = 12 903.2 h−1), which was ten times and sixty times higher than that of Si@[β-Ki-Pd] (TOF = 1171.7 h−1) and Li2PdCl4 (TOF = 215.8 h−1), respectively. It also showed good substrate adaptability and could be reused 13 times. Si@[β-Ki-Pd][L2-Pd]11 was a heterogeneous catalyst and catalysis occurred on the surface. Active sites formed in situ on the surface, including Pd(0) and Pd(0)/PdO, which exhibited a synergistic effect, such as electronegative Pd(0), were enhanced via the synergistic action between PdO and Pd(0). This synergistic effect made the oxidative addition of Pd reacting with aryl halide easy and boosted catalytic activity. Oxygen also played a crucial role in the formation of PdO, which not only exhibited important electron transferring synergy with Pd, but acted as a stabilizer for Pd(0). This could maintain the balance ratio of Pd/PdO to prevent Pd from aggregating. The above investigation is essential for the optimal design of highly active catalysts.
By functionalizing various polyphenyl nuclei with ester groups, five kinds of polyphenyl benzoate based electrochromic materials (M1–M5) are synthesized and characterized. These materials show typical aggregation-induced emission and aggregation-enhanced emission in water/N-methylpyrrolidone, good electrochemical properties, and an obvious electrochromic phenomenon. In the process of electrochemical reduction, each material shows distinct and well-separated redox couples, the introduction of ester moieties makes electron transfer much easier compared to the polyphenyl nuclei, and the synergistic effect of the ester group and polyphenyl structure reduces the LUMO level of the corresponding polyphenyl benzoates. In contrast, the polyphenyl nuclei markedly affect their electrochromic properties, and the electrochromic devices based on M1–M5 exhibit five different colored states. By combining with density functional theory calculations, it is found that an appropriate amount of benzene rings in the central benzene cores (M2 and M4) can effectively improve the coloration efficiency, response time, and switching stability; fewer benzene rings in the central benzene core (M1) cannot achieve stable conjugation of the material in the reduced state, while an excess of benzene rings in the central benzene core (M5) leads to excessive molecular volume, and this will lead to space congestion and is not beneficial for electron transfer. The application of M1–M5 in multi-colored functional display devices is explored, indicating its potential application prospect in display fields.
This article considers the problem of the influence of the solvation shell on the ultraviolet-visible absorption spectra of π-conjugated complexes of different metal ions with dicarbonyl ligands. Based on a wide spectral dataset that has been previously collected, we report the direct correlation between the wavelength of maximum absorbance of the complexes and the coordination properties of the metal ions. Chalcogen-bearing diketones (2-furoyl-trifluoroacetone, 2-thenoyl-trifluoroacetone, 2-selenophen-trifluoroacetone, and 2-tellurophen-trifluoroacetone) demonstrate a significant redshift (17–29 nm) of the absorption bands for complexes of metal ions with various solvation shells. The spectral shift increases with an increasing number of water molecules in the hydration sphere. Detailed measurements show the red shift even for different lanthanide complexes. The discovered relationships allow us to compare at a qualitative level the structure of the solvation shell of π-conjugated dicarbonyl complexes.
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