Latest ArticlesWhite light illumination is essential in daily life, however, the substantial amount of blue light it contains can damage human eyes. Therefore, it is important to block this high-energy blue light to protect visual health. In this study, yellow-emitting carbon dots (CDs) with a quantum yield exceeding 94% were synthesized using citric acid and urea. These CDs effectively absorb blue light. By incorporating them into polystyrene, multiple films termed CDs-based blue light blocking films (CBFs) were developed, each offering different levels of blue light absorption. These CBFs exhibited excellent transparency and efficient blue light filtering capabilities. This study highlights the potential of high quantum yield CDs, which specifically absorb blue light, as foundational materials for developing light-blocking solutions against high-energy short-wavelength light.
The considerable hazard posed by periprosthetic joint infections underlines the urgent need for the rapid advancement of in-situ drug delivery systems within joint materials. However, the pursuit of sustained antibacterial efficacy remains a formidable challenge. In this context, we proposed a novel strategy that leverages swelling and erosion mechanisms to facilitate drug release of drug-loaded ultrahigh molecular weight polyethylene (UHMWPE), thereby ensuring its long-lasting antibacterial performance. Polyethylene oxide (PEO), a hydrophilic polymer with fast hydrating ability and high swelling capacity, was incorporated in UHMWPE alongside the antibacterial tea polyphenol (epigallocatechin gallate, EGCG as representative). The swelling of PEO enhanced water infiltration into the matrix, while the erosion of PEO balanced the release of the encapsulated EGCG, resulting in a steady release. The behavior was supported by the EGCG release profiles and the corresponding fitted release kinetic models. As demonstrated by segmented antibacterial assessments, the antibacterial efficiency was enhanced 2 to 3 times in the PEO/EGCG/UHMWPE composite compared to that of EGCG/UHMWPE. Additionally, the PEO/EGCG/UHMWPE composite exhibited favorable biocompatibility and mechanical performance, making it a potential candidate for the development of drug-releasing joint implants to combat prosthetic bacterial infections.
Sensitization of metal-centered forbidden transitions is of great significance. Solid MnⅡ-based phosphors with d-d forbidden transition sensitized by CeⅢ with d-f allowed transition are promising light conversion materials, but the energy transfer mechanism in CeⅢ-MnⅡ is still in dispute for the uncertainty of distances between metal centers. Herein, for the first time, we explored the energy transfer mechanism in two well-designed luminescent heteronuclear complexes with clear crystal structures, i.e., Ce-N8-Mn and Ce-N2O6-Mn (N8 = 1,4,7,10,13,16,21,24-octaazabicyclo[8.8.8]hexacosane; N2O6 = 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane). Short distances between metal centers facilitate efficient energy transfer from CeⅢ to MnⅡ in both complexes, resulting in high photoluminescence quantum yield up to unity. After systematic study of the two heteronuclear complexes as well as two reference complexes Ce(N8)Br3 and Ce(N2O6)Br3, we concluded that dipole-quadrupole interaction is the dominant energy transfer mechanism in the heteronuclear complexes.
Wearable flexible sensor devices have the characteristics of lightweight and miniaturization. Currently, power supply and detection components limit the portability of wearable flexible sensor devices. Meanwhile, conventional liquid electrolytes are unsuitable for the integration of sensing devices. To address these constraints, wearable biofuel cells and flexible electrochromic displays have been introduced, which can improve integration with other devices, safety, and color-coded display data. Meanwhile, electrode chips prepared through screen printing technology can further improve portability. In this work, a wearable sensor device with screen-printed chips was constructed and used for non-invasive detection of glucose. Agarose gel electrolytes doped with PDA-CNTs were prepared, and the mechanical strength and moisture retention were significantly improved compared with traditional gel electrolytes. Glucose in interstitial fluid was non-invasive extracted to the skin surface using reverse iontophoresis. As a biofuel for wearable biofuel cells, glucose drives self-powered sensor and electrochromic display to produce color change, allowing for visually measurement of glucose levels in body fluids. Accurate detection results can be visualized by reading the RGB value with a cell phone.
Preparing free-base porphyrinoid radicals that can function as coordination ligands is a challenging task. Here we report the synthesis of a stable, free-base benzocorrole (BC) radical containing only two inner NH protons via a retro-Diels-Alder conversion. The radical character of BC was fully supported by crystallographic analysis, spectroscopic evidence, and theoretical calculations. This neutral radical ligand allowed easy insertion of Zn(Ⅱ), Ga(Ⅲ), and Pd(Ⅱ) ions to produce radical complexes. All these radicals exhibited luminescence-on responses under weak reducing atmosphere, corresponding to the conversion to their aromatic anions. The red fluorescence was observed for BC and its Zn(Ⅱ) and Ga(Ⅲ) complexes, and the near-infrared phosphorescence (> 900 nm) was detected for Pd(Ⅱ) complex at room temperature. Furthermore, Ga(Ⅲ) corrole exhibited a variation in fluorescence in response to axial coordination. Our findings provide a promising radical platform for coordination and developing novel functional materials with switchable spin and emission.
Herein, we fabricate an embedding structure at the interface between Pt nanoparticles (NPs) and CeO2-{100} nanocubes with surface defect sites (CeO2-SDS) through quenching and gas bubbling-assisted membrane reduction methods. The in-situ substitution of Pt NPs for atomic-layer Ce lattice significantly increases the amount of reactive oxygen species from 133.68 µmol/g to 199.44 µmol/g. As a result, the distinctive geometric structure of Pt/CeO2-SDS catalyst substantially improves the catalytic activity and stability for soot oxidation compared with the catalyst with no quenching process, i.e., its T50 and TOF values are 332 ℃ and 2.915 h-1, respectively. Combined with the results of experimental investigations and density functional theory calculations, it is unveiled that the unique embedding structure of Pt/CeO2-SDS catalyst can facilitate significantly electron transfer from Pt to the CeO2-{100} support, and induce the formation of interfacial [Ce-Ox-Pt2] bond chains, which plays a crucial role in enhancing the key step of soot oxidation through the dual activation of surface lattice oxygen and molecular O2. Such a fundamental revelation of the interfacial electronic transmission and corresponding modification strategy contributes a novel opportunity to develop high-efficient and stable noble metal catalysts at the atomic level.
A series of heteronuclear yttrium-nickel monoxide carbonyl complexes YNiO(CO)n− (n = 1–5) were generated in a pulsed-laser vaporization source and characterized by mass-selected photoelectron velocity-map spectroscopy combined with theoretical calculations. CO ligand-mediated reactivity in CO oxidation of yttrium-nickel monoxide carbonyl complexes was experimentally and theoretically identified. During the consecutive CO adsorption, a μ2-O linear structure was most favorable for YNiO(CO)n− (n = 1, 2), then a structure in which the terminal O was bonded to the Y atom became favored for YNiO(CO)3−, and finally a structure bearing a CO2 moiety was most favorable for YNiO(CO)n− (n = 4, 5). Theoretical calculations indicated that the Ni atom acted as an electron acceptor and accumulated electron density at n ≤ 3, and then served as an electron donor along with the Y atom to contribute electron density in the rearrangement that accompanied CO oxidation at n > 3.
The development of innovative and sustainable catalytic strategies for organic synthesis is a pivotal aspect of advancing material science and chemical engineering. This research presents a new catalytic method for the aminoacylation of N-sulfonyl ketimines by utilizing a potassium-doped graphite-like carbon nitride (g-C3N4) framework. This method not only enhances the catalytic efficiency and broadens the light absorption spectrum of g-C3N4 but also significantly reduces the recombination rate of electron-hole pairs, thereby increasing the reaction yield and selectivity. Importantly, our approach facilitates the synthesis of aminoacylated N-heterocycles, expanding the applicability of potassium-modified g-C3N4 in photocatalytic organic synthesis. A notable accomplishment of this study is the unprecedented generation of carbamoyl radicals via heterogeneous photocatalysis, which can be easily recycled after reaction. This advancement highlights the capability of potassium-doped g-C3N4 (namely K-CN) as an advanced heterogeneous photocatalyst for the formation of complex organic compounds.
The quest for efficient and durable catalysts using abundant resources has garnered significant interest in the field of bifunctional oxygen electrocatalysis. In this contribution, we have designed a FeN4 or CoN4 embedded graphene-based bilayer as active layer and TMC3 or TMN3 doped graphene as supporting layer, named as FeN4/TMC3 or FeN4/TMN3 and CoN4/TMC3 or CoN4/TMN3, wherein TM strands for transition metal. Based on density functional theory calculations, our results demonstrate that the interaction formed between dual metal atoms in the bilayer interspace leads to the coordination environment altered from flat four-coordination to spatial five-coordination, further stabilizing the bilayer structure and impairing its affinity toward the O-containing intermediates. According to thermodynamic analysis, the bilayers of CoN4/CoN3, FeN4/FeC3, FeN4/CoC3, FeN4/NiC3, FeN4/ZnC3, FeN4/FeN3, FeN4/CrN3 and FeN4/ZnN3 are attractively promising for bifunctional oxygen electrocatalysis due to the small overpotential difference Δη between oxygen reduction and oxygen evolution that are less than 1 V. Density functional theory calculations combined with machine learning analysis directly identify the key role played by the inter-binding formed between bilayers, that boosts catalytic activity, which establishes a predictable framework for a fast screen for graphene-based bilayer vertical heterojunction. This work opens up a new path for designing the efficient electrocatalysts via modification of coordination environment.
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