Latest ArticlesRoom temperature phosphorescent (RTP) materials have a variety of applications ranging from bio-imaging, optoelectronic devices to information security protection. However, the preparation procedures for these materials are always tedious and time-consuming. Here, we report a micro-wave approach to prepare RTP carbon dots (CDs) in only 8 min. The micro-wave promoted the carbon and boron bond formation using natural compounds glucose and boric acids. This result has been confirmed using TEM, FTIR, XPS and XRD measurements. The C-B hetero atomized material presented a long afterglow property. With the irradiation with UV light, we observed an eight-second RTP by naked eyes after the lamp was turned off, and the phosphorescence lifetime was 487 ms. This excellent performance was mainly due to the formation of B-C bonds that promoted the intersystem crossings (ISC) and non-radiation transition of triplet states. Moreover, the glass state of the materials also helped to stabilize the triplet states of B-CDs and made its non-irradiation inactivated, which resulted in the characteristics of yellow green RTP. These results have demonstrated that micro-wave is a convenient and effective strategy to make hetero atomized RTP material, providing new possibilities for their industrial productions.
Selenization reaction with the in situ prepared NaHSe has been successfully developed to occur in aqueous solution. The technique affords a method to upload the bioactive Se element on cotton products in semi-industrial scale. The antibacterial tests revealed that the selenized cotton possessed a potent and prolonged antimicrobial effect against both Gram-positive S. aureus and Gram-negative E. coli bacteria. This work discloses a practical method for preparing the selenium-containing antibacterial materials concisely and directly with industrial application potential.
Two-dimensional (2D) transition metal dichalcogenide (TMD) nanosheets have attracted considerable attention owing to their diverse properties and great potential in a wide range of applications. In order to further tune their properties and then broaden their application domain, large efforts have been devoted into engineering the structures of 2D TMD nanosheets at atomic scale, especially the alloying technology. Alloying different 2D TMD nanosheets into 2D alloys not only offers the opportunities to fine-tune their physical/chemical properties, but also opens up some unique properties, which are highly desirable for wide applications including electronics, optoelectronics and catalysis. This review summarizes the recent progress in the preparation, characterization and applications of 2D alloyed TMD nanosheets.
Formaldehyde is an important air pollutant and its removal is essential to protect human health and meet environmental regulations. Ag-based catalyst has a considerable potential for HCHO oxidation in low temperature range. The valence state of Ag is one of the key roles in formaldehyde catalytic oxidation. However, its effect on activity is still ambiguous. Non-thermal plasma and conventional calcination were employed to regulate Ag valence state in this study. Three Ag-Co/CeO2 catalysts with totally different distribution of Ag species were obtained. A special mixed Ag valence state, ~50% Ag+ with a few Ag0 and Ag+, was achieved by plasma activation. It had the merits of both good activity and stability. A close relationship between Ag valence state and the activity for HCHO oxidation was established. The activity of different Ag species follows the order: Ag+ + Ag0 + Ag+ > Ag+ > Ag0 > Ag+.
Sodium (Na) O2 batteries have high energy density and low cost. However, high polarization, complex discharge products, and low Coulombic efficiency (CE) lead to poor cyclability. Here, we proposed an atomically dispersed Ru catalyst on nitrogen-doped graphene for Na-O2 batteries. The catalysts enable the discharge to proceed via a surface-mediated route, which leads to uniform deposition of Na2-xO2 and low polarization during recharge. The first-principle calculation revealed that Ru-N4 complex in the catalyst has strong chemical adsorption to intermediate superoxides, facilitating uniform deposition and enhancing rapid kinetics. In contrast, Ru nanoparticles, despite the catalytic activity, induce bulk deposition via a solution-mediated route because the exposed graphene surface shows weak interaction to superoxides, thereby lowering CEs and cyclability. In brief, the atomically-dispersed Ru catalyst endows Na-O2 batteries with excellent electrochemical properties via a surface-mediated discharge.
Li‒S batteries have shown great potential as secondary energy batteries. However, the side reaction between Li anodes and polysulfides seriously limited their practical application. Herein, the artificial protective film, which is consisted of Li-Nafion and TiO2, was designed and successfully prepared to achieve a corrosion-resistant Li anode in Li-S battery. In the composite protective film, the Li-Nafion could efficiently prevent the contact between Li anodes and polysulfides, and the incorporation of TiO2 nanoparticles into the Nafion could significantly increase the ionic conductivity and mechanical strength of the protective film. Li-Li symmetric cells with an optimal artificial protective film exhibited an extended cycle-life of 750 h at a current density of 1 mA/cm2 in Li2S8 electrolyte. Moreover, the Li‒S full battery with an optimal protective Li anode exhibited higher capacity retention of 777.4 mAh/g after 100 cycles at 0.1 C as well as better rate performance than the cell with a pure Li anode. This work provides alternative insights to suppress the side reaction for Li‒S batteries with high capacity retention.
As a kind of microplasma sustained in air, solution electrode glow discharge (SEGD) ignited between the liquid electrode and metal electrode is attractive to the fields of optical emission spectrometry and mass spectrometry due to its unique advantages, such as low power consumption and low carrier gas consumption. Moreover, the complex and efficient reactions in the liquid phase and plasma phase of SEGD make it considerable research potential in the fields of biology and medicine, material synthesis, electrochemistry. Considering the close relationship between the various fields on SEGD, here we are devoted to provide an overview of the development of SEGD in various fields. More importantly, a systematic discussion on the discharge mechanism is conducted based on the research process in various fields for getting deeper insight into the SEGD.
MoS2 nanosheets (NSs) are novel 2D nanomaterials (NMs) with potential uses in many areas, and therefore oral exposure route to MoS2 NSs is plausible. Currently, MoS2 NSs are considered as biocompatible NMs, but there is lacking of systemic investigations to study the interactions of MoS2 NSs with intestinal cells. In this study, we exposed the 3D Caco-2 spheroids to MoS2 NSs or MoS2 powders (denoted as MoS2-bulk), and investigated the potential adverse effects of MoS2-materials based on transcriptomics and lipidomics analysis. As expected, both MoS2 NSs and MoS2-bulk were dose-dependently internalized into 3D Caco-2 spheroids but did not induce cytotoxicity, membrane disruption or decrease of thiols. However, the Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) analysis indicated that nutrient absorption and metabolism was decreased. One of the most significantly decreased KEGG pathways is fat digestion and absorption (map04975), and Western blotting analysis further showed that fatty acid binding protein 1 and apolipoprotein A1, key proteins involved in fat digestion and absorption, were down-regulated by MoS2 NSs or MoS2-bulk. In addition, BODIPY 493/503 staining suggested that exposure to MoS2 NSs and MoS2-bulk decreased lipid levels in the spheroids. However, lipidomics data indicated that MoS2 materials only decreased 8 lipid classes, including lysophosphatidylcholine, lysodimethylphosphatidylethanolamine, N-acylethanolamine, ceramide phosphoethanolamines, gangliosides, lysosphingomyelin and sulfatide, whereas most of the lipid classes were indeed increased. In addition, MoS2 NSs was more potent to decrease the lipid classes compared with MoS2-bulk. Combined, the results from this study showed that MoS2 NSs and bulk materials were non-cytotoxic but altered lipid profiles in 3D Caco-2 spheroids.
The engineering of carbon nanocatalysts for the persulfate activated elimination of emerging organic contaminants (EOCs) demonstrates promising potential compared with metal-based counterparts due to their unique advantage of high stability and low toxicity. The early reviews introduced the theoretical background of persulfate activation together with a detailed summary of different mechanisms responsible for degradation of EOCs. To further unify the state of knowledge, identify the research gaps, and prompt new research in this area, we present a thorough review on current trends in research on metal-free carbon nanocatalysts (e.g., 0D nanodiamond, 1D carbon nanotubes and carbon nanofibers, 2D graphene and graphitic carbon nitride, and 3D carbon nanocatalysts), with emphasis on their applications in persulfate activation and EOCs decontamination. We also discuss the current challenges and future perspectives in practically relevant applications. Last, we highlight that the development of sustainable carbon nanocatalysts/persulfate systems lies at the interface of multiple disciplines, which calls for future in-depth interdisciplinary collaborations.
A sulfonium ylide participated alkylation and arylation under transition-metal free conditions is described. The disparate reaction pattern allowed the separate activation of non-ylidic S-alkyl and S-aryl bond. Under acidic conditions, sulfonium ylides serve as alkyl cation precursors which facilitate the alkylations. While under alkaline conditions, cleavage of non-ylidic S-aryl bond produces O-arylated compounds efficiently. The robustness of the protocols were established by the excellent compatibility of wide variety of substrates including carbohydrates.