Latest ArticlesThe rational design of high-performance bifunctional electrocatalysts for overall water splitting (OWS) is the key to popularize hydrogen production technology. The active metal oxyhydroxide (MOOH) formed after surface self-reconfiguration of transition metal sulfide (TMS) electrocatalyst is often regarded as the "actual catalyst" in oxygen evolution reaction (OER). Herein, an Fe doped CoS2/MoS2 hollow TMS polyhedron (Fe-CoS2/MoS2) with rich Mott-Schottky heterojunction is reported and directly utilized as an OWS electrocatalyst. The spontaneous built-in electric field (BEF) at the heterogeneous interface regulates the electronic structure and D-band center of the catalyst. More importantly, the “TMS-MOOH” core-shell structure obtained in the KOH electrolyte shows enhanced OER properties. And the introduction of Fe ions activates the inert basal plane of MoS2, which greatly steps up the performance of HER. Hence, the preferable Fe-CoS2/MoS2–400 presents superior OER activity (η10 = 178 mV, η100 = 375 mV), HER activity (η10 = 92 mV) and ultra-high stability for 50 h. This work has deeply explored the catalytic mechanism of TMS and provided a new idea for the construction of efficient bifunctional catalysts.
The sequestration of 99Tc represents one of the most challenging tasks in nuclear waste decontamination. In the event of a radioactive waste leak, 99TcO4– (a main form of 99Tc) would spread into the groundwater, a scenario difficult to address with conventional anion exchange materials like resin and inorganic cationic sorbents. Herein, we present a nickel(Ⅱ) metal-organic framework (MOF), TNU-143, featuring 3D four-fold interpenetrated networks. TNU-143 exhibits efficient ReO4– (a nonradioactive analogue of 99TcO4–) removal with fast anion exchange kinetics (< 1 min), high sorption capacity (844 mg/g for ReO4–), and outstanding selectivity over common anions. More importantly, TNU-143 shows superior stability in alkaline solution and can remove 91.6% ReO4– from simulated alkaline high-level waste (HLW) streams with solid-liquid ratio of 40 g/L. The uptake mechanism is elucidated by the single-crystal structure of TNU-143(Re), showing that ReO4– anions are firmly coordinated to nickel cation to result in a 2D layered structures. Density functional theory (DFT) calculations confirm the transformation from TNU-143 to TNU-143(Re) is a thermodynamically favorable process. This work presents a new approach to the removal of ReO4–/99TcO4– from alkaline nulcear fuel using MOF sorbents.
Electrocatalytic reduction of nitrate (NO3−) at low concentrations to ammonia (NH4+) still faces challenges of low NO3− conversion and NH4+ selectivity due to the sluggish mass transfer and insufficient atomic hydrogen (H*) supply. Herein, we propose CuO/NiO heterojunction with the assistance of a built-in electric field to enhance mass transfer and H* provision. The built-in electric field in CuO/NiO is successfully formed as demonstrated by X-ray photoelectron spectroscopy and ultraviolet photoemission spectroscopy. The results reveal that CuO/NiO achieves high NO3− reduction activity (100%) and NH4+ selectivity (100%) under low NO3− concentration conditions (100 mg/L NO3−, ca. 22.6 mg/L NO3−-N), which is superior to that of many recently reported electrocatalysts. Density functional theory calculations further clarify that the built-in electric field triggers the enhanced adsorption of reactants on CuO/NiO heterojunction interface and strong d-p orbital hybridization between reactants and CuO/NiO. Besides, the free energy diagram of hydrogen evolution reaction of CuO/NiO confirms the realization of enhanced H* provision. Moreover, coupling experiments and consecutive cycle tests demonstrate the potential of CuO/NiO in practical applications. This work may open up a new path and guide the development of efficient electrocatalysts for electrocatalytic reduction of NO3− at low concentrations to NH4+.
Aromatic aldehydes are the most fundamentally important compounds used in organic synthesis. The development of new synthetic methods for introduction of a formyl group into an organic scaffold is highly desirable. In this report, a nickel-catalyzed reductive coupling between aryl halides and α–chloro N-methoxyphthalimide has been documented for the synthesis of a diverse array of aromatic aldehydes. Because of mild reductive coupling conditions, excellent functional group tolerance, especially for substrates containing free -OH and -NH2, was observed. Due to the simple operation mode, a large library of aromatic aldehydes can be quickly constructed by this process. Moreover, the present protocol is amenable for late-stage functionalization of bioactive compound. A combined computational and experimental investigation suggested the reaction may undergo a reaction mechanism of active Ni(I) catalyst formation and the formation of key formyl radical intermediate under zinc reductive conditions.
Antibiotics present in surface water have detrimental effects on both human health and the ecosystem. Additionally, they pose a threat to the effectiveness of biological water treatment processes. In this study, a visible photocatalytic system with BiOCl/g-C3N4 heterojunction was developed to remove sulfonamide antibiotic sulfamerazine (SMZ) in water. The removal rate reached 92.77% under visible light irradiation for 80 min. This photocatalyst remained active after 5 cycles of experiments and maintained a relatively stable removal rate of SMZ of over 80%. The ESR tests indicate that the main active species in this photocatalytic system were h+ and •O2−. The enhanced photocatalytic efficiency was mainly ascribed to the formation of a built-in electric field between BiOCl and g-C3N4 through the carrier transport mechanism of the S-scheme heterojunction. This heterojunction facilitated the photogenerated carrier shift and segregation, and improved the interfacial charge transfer efficiency, as confirmed by photoelectrochemical test and Density functional theory (DFT) calculations. The HPLC-QTOF-MS/MS and DFT analysis revealed possible degradation pathways of SMZ may involve deamination, hydroxylation, SO2 extrusion and bond breaking. This novel BiOCl/g-C3N4 heterojunction has proven to be essential for efficient visible-light photocatalysis.
Ensuring the timely and precise monitoring of severe liver diseases is crucial for guiding effective therapies and significantly extending overall quality of life. However, this remains a worldwide challenge, given the high incidence rate and the presence of strong confounding clinical symptoms. Herein, we applied a convenient and high-yield method to prepare the magnetic mesoporous carbon (MMC-Fe), guided by a composite of resol and triblock copolymer. With the combination of MMC-Fe, high-throughput mass spectrometry, and a simple machine learning algorithm, we extracted N-glycan profiles from various serum samples, including healthy controls, liver cirrhosis, and liver cancer, and from which we screened specific N-glycans. Specifically, the selected N-glycans demonstrate exceptional performance with area under the curve (AUC) values ranging from 0.948 to 0.993 for the detection of liver diseases, including alpha fetoprotein (AFP)-negative liver cancer. Among them, five N-glycans holds potential in monitoring distinctions between liver cirrhosis and AFP-negative liver cancer (AUC values of 0.827–0.842). This study is expected to promote the glycan-based precise monitoring of diseases, not limited to liver disease.
The catalytic asymmetric dipolar cycloaddition reaction is efficient for the construction of various chiral valuable carbo- and heterocycles. Thus, the design and exploration of new dipoles and the subsequent control of their reactivity for various stereoselective cycloadditions are significant aspects of modern organic synthesis. Herein, we have developed a series of vinyl cyclic carbamates containing an oxazolidine-2,4–dione fragment and used them as reactive precursors for in situ generation of amide-based aza-π-allylpalladium 1,3-dipoles, which could be applied to asymmetric decarboxylative 1,3-dipolar cycloaddition with different types of dipolarophiles containing C=C, C=N, and C=O double bonds. This strategy provides an opportunity for the synthesis of previously unusual structures, such as highly functionalized optically pure pyrrolidin-2-ones, imidazolidin-4-ones, and oxazolidin-4-ones. This protocol also has significant features including wide substrate scope, mild reaction conditions, simple operation, and good to excellent results (70 examples, up to 99% yield, >20:1 dr and 99% ee). This unique method significantly expands the reaction range of the amide-based aza-π-allylpalladium 1,3-dipoles compared to the precedents.
BA2(MA)n-1PbnI3n+1 series low-dimensional (2D) perovskites have been widely investigated for their remarkable environmental stability, but still suffer the poor light absorption and disordered phase distribution, hindering their practical applications. In this work, we combine the introduction of FA and the addition of PbCl2 to optimize the film quality, strengthen the light absorption, regulate internal phase distribution, and promote carrier transport inside 2D perovskite films. The incorporation of FA promotes sufficient light absorption and improve the film crystallinity. Furthermore, the addition of PbCl2 eliminates the low n phase (n = 1) and suppresses the forming of the low n phase of n = 2, enhancing the film conductivity and diminishing carrier recombination. The synergistic of A-site cation engineering and phase manipulation achieves a high efficiency of 16.48%. Importantly, the synergistic prepared perovskite film does not show any changes after 60 days in the air with an average humidity of 57% ± 3%, and the corresponding solar cell maintains 85% of the original efficiency after more than 800 h, demonstrating remarkable environmental stability. The results indicate that the synergistic of A-site cation engineering and phase manipulation is promising for producing superior efficiency, along with satisfying humidity stability.