Inorganic Chemistry Frontiers最新文献

It is highly desirable but challenging to design multi-functional materials for energy storage and electromagnetic (EM) wave absorption. Herein, core–shell CaSnO₃@N-doped carbon (CSO@NCNF) coaxial nanocables with one-dimensional (1D) architecture were synthesized by employing the electrospinning method combined with in situ polymerization and heat treatment. In the resulting structure, the CaSnO₃ nanofiber (CSONF) core with an average diameter of 52.5 nm is confined in the high electronic conductivity of the N-doped carbon sheaths with a thickness ranging from 27.3 to 67.2 nm. The lithium storage performance of the CSO@NCNF nanocable electrode is much higher than that of the CSONF electrode; this is owing to the (i) large number of void spaces and active sites generated by the structure of the 1D core–shell nanocables, (ii) fast transport network constructed by carbon sheaths prominently enhancing the transport of both electrons and lithium ions, and (iii) structural stability achieved through the buffering mechanism created by CaSnO₃@NCNF coaxial construction. However, its ingenious structural design, multiple heterogeneous interfaces and multi-component strategy give rise to a synergistic mechanism of impedance matching, conductive loss, polarization loss and multiple reflection/scattering. The coaxial nanocables display good microwave absorption (MA) properties, featuring a reflection loss (RL) value of −47.0 dB at 8.2 GHz and 2.5 mm as well as an effective absorption bandwidth (EAB) of 4.7 GHz at 1.4 mm. This unique structural design is believed to provide a reference for the preparation of multi-functional materials.

Electrocatalytic water electrolysis is intrinsically limited by the slow kinetics of the oxygen evolution reaction (OER) at the anodic electrode. Building on our previous work, we utilized a porous metal–organic framework (CoOF-1) structurally characterized by rich adsorption sites for Ru(III) ions. In this study, the incorporation of noble metal species into the CoOF-1-derived porous Co₃O₄ matrix effectively improves electrocatalytic OER performance. The optimized Ru-Co₃O₄-5 exhibits an overpotential of 260 mV at 10 mA cm⁻², a Tafel slope of 84 mV dec⁻¹, and a satisfactory current retention of 95.8% over 20 hours. This enhanced OER activity results from the introduction of Ru to modulate the surface electron distribution as well as the large specific surface area. Furthermore, both the in situ Raman test and XPS analysis confirm the robust structural stability of Ru-Co₃O₄. This study provides a new approach for MOF-derived porous ruthenium-doped Co₃O₄ nanomaterials with high activity and durability, showcasing great potential in the field of practical energy storage and conversion.

Dative boron ← nitrogen (B ← N) bonds are important in the construction of crystalline covalent organic polymers/frameworks (COPs/COFs). Herein, 9,10-di(4-pyridyl)anthracene (DPA) and 1,4-bis(benzodioxaborolane)benzene (BACT) were employed as building blocks to prepare single crystals of a functional COP (CityU-30). Detailedly, DPA and BACT were connected together through dative B ← N bonds to form zigzag polymer chains, and the neighboring chains interacted with each other through hydrogen bonds to form a pseudo-two-dimensional structure. The observed significant decrease in the fluorescence intensity of CityU-30 compared to that of DPA indicates a pronounced photothermal effect in CityU-30. This research reveals the crucial role of B ← N bonds in designing innovative COPs and guides future materials research studies.

ZnIn₂S₄ nanosheets with tunable concentration of dual vacancies (i.e. Zn vacancy and S vacancy) were prepared and used for photocatalytic H₂O₂ production. Introducing dual vacancies effectively promotes exciton dissociation, facilitates O₂ adsorption, and reduces the free energy of subsequent activation and protonation of adsorbed O₂. These intriguing properties endow ZnIn₂S₄ with excellent performance for sacrificial agent-free H₂O₂ photosynthesis via a two-step single-electron oxygen reduction reaction pathway under AM 1.5 and visible-light irradiation. Almost double amounts of H₂O₂ can be produced over ZnIn₂S₄ with dual vacancies compared to pristine ZnIn₂S₄ without vacancies. Corresponding SCC efficiency and AQY at 420 ± 20 nm reached ∼0.031% and 0.34%, respectively. In addition, the abundant dual vacancies inhibit H₂O₂ decomposition because of enhanced hydrophilicity. This work provides a new strategy to improve the photocatalytic performance of ZnIn₂S₄ through defect engineering and brings new mechanistic insights into the role of these defects.

The development of cost-effective metal molybdates with enhanced energy storage capabilities has garnered significant attention as promising redox-active electrodes for asymmetric supercapacitors (ASCs). In this work, we synthesized binder-free copper molybdate (CMO) nanostructures on nickel foam using a simple hydrothermal process and thoroughly investigated their structural and electrochemical properties. The resulting CMO nanostructures exhibited a hybrid nanosheet–nanoplate morphology with a layered structure, providing an increased electroactive surface area. The structural integrity and elemental composition were confirmed using X-ray diffraction, X-ray photoelectron and X-ray (EDX) spectroscopy, showing a homogeneous distribution of copper, molybdenum, and oxygen elements. Electrochemical analysis showed that the hydrated CMO (CMO_BH) electrode provides higher specific capacitance and redox behavior than the thermally treated CMO (CMO_AH) electrode. The higher performance is attributed to the superior conductivity of CMO_BH and the presence of hydroxyl groups, which enhance redox-type charge storage. Moreover, the ASC device fabricated using the hydrated CMO_BH and activated carbon electrodes achieved a high operating voltage of 1.6 V with a maximum specific capacitance of 142.1 F g⁻¹ at 1 A g⁻¹, an energy density of 48.6 W h kg⁻¹ and a power density of 12.5 kW kg⁻¹, respectively. Additionally, the device demonstrated excellent cycling stability, retaining 89.1% of its capacitance after 10 000 cycles. The ASCs also successfully powered light-emitting diodes, emphasizing their potential for practical energy storage applications.

Near-infrared (NIR) luminescence materials are ideal candidates for applications in three-dimensional biomedical imaging and night vision. Here, we constructed an ultra-broadband NIR material based on LiBaF₃:Ni²⁺ single crystals with NIR emission at 1400 nm and a full width at half maximum (FWHM) of 254 nm from 1100 to 1700 nm wavelengths, covering the NIR-II and NIR-III regions. Through the activation of inactive Mg²⁺, the NIR emission could be improved by a factor of two, and the FWHM enhanced to 273 nm. This is ascribed to the lattice distortion by the addition of Mg²⁺ as well as the charge asymmetry between the Mg²⁺ and Li⁺ ions. The prepared Ni²⁺/Mg²⁺-doped NIR perovskite single crystals were packaged with a commercial high-efficiency near-ultraviolet LED chip (@395 nm) to construct NIR single-crystal LEDs, and their promising applications with high efficiency were demonstrated in NIR night-vision monitoring and vein non-destructive imaging.

Metal organic frameworks (MOFs) are polymeric solid-state coordination compounds that can link photoactive and catalytically active molecular entities and maintain their activity and mechanism within their 3D structure, resembling the large photosynthetic apparatus in natural photosynthesis. This review categorizes photocatalytically active MOFs according to their structural properties and the location of the photosensitizer (PS) and catalyst (CAT) in the following types with respect to the linker and secondary building unit (SBU): (I) the PS and CAT are represented or localized at the linker and SBU, respectively, (II) the PS and CAT are represented or localized by/at different linkers, (III) the PS and CAT are both bound to the SBU, (IV) the PS and CAT are bound to the linker or SBU but as a PS-CAT dyad, and (V) the PS and/or CAT are assembled non-covalently within MOF pores. Furthermore, all reported studies on artificial photosynthesis are summarized in the context of light-driven H₂ evolution, CO₂ reduction, overall water splitting, water oxidation and other oxidations such as alcohol and amine oxidation, which are relevant in the field of artificial photosynthesis. Additionally, this review presents an overview on the stability and repair strategies for these MOFs.

Birefringent crystals for modulating the polarization of light are of technological importance in optical communications. Herein we provide two novel two-dimensional hybrid halide perovskites, [(H₂-dpys)(PbBr₄)] (1) (dpys = di(pyridin-4-yl)sulfane) and [(H-cmpy)₄(Pb₃Br₁₀)] (2) (cmpy = 4-chloro-3-methylpyridine), which can act as birefringent crystals. Remarkably, the crystal structures and the optoelectronic performance of the hybrid lead bromide perovskites are elaborately regulated by the organic cations of pyridine derivatives. Compound 2 constructed from the H-cmpy⁺ cations containing the single pyridyl moiety has a significantly enhanced birefringence (0.315@550 nm) compared to compound 1 (0.192@550 nm) with two pyridyl moieties of H₂-dpys²⁺ cations, and it is larger than those of all commercial birefringent crystals and most of the hybrid metal halide perovskites. The results of the theoretical calculations showed that the highly distorted PbBr₆ octahedra and the delocalized π-conjugation of H-cmpy⁺ cations synergistically contribute to the enhanced birefringence of 2. This work provides a useful strategy for modulating the crystal structure and optoelectronic performance of the hybrid lead halide perovskites.

The development of metal–organic frameworks (MOFs) that simultaneously possess high adsorption capacity and selectivity for benzene (Bz)/cyclohexane (Cy) separation is a formidable challenge. In this study, we employ the mixed-ligand approach to construct two novel isoreticular MOFs, designated DZU-72 and -73, to regulate Bz adsorption and Bz/Cy separation performances. Guided by the linker engineering, we have incorporated distinct dicarboxylate ligands, benzene-1,4-dicarboxylic acid (H₂BDC) and naphthalene-2,6-dicarboxylic acid (H₂NDC) with different aromatic rings, as second ligands into the frameworks of two MOFs, respectively. Vapor adsorption tests demonstrate that DZU-73 featuring naphthalene ring units exhibits superior uptake for Bz (6.92 mmol g⁻¹) compared to DZU-72 (Bz: 4.30 mmol g⁻¹) with benzene ring units. The calculated selectivity for Bz/Cy separation shows that DZU-73 has an IAST selectivity value of about 28.1, nearly 2.5 times that of DZU-72 (11.3). Breakthrough experiments further reveal that DZU-73 can effectively separate Bz/Cy mixed vapors with an interval time of 17.6 min g⁻¹. Density functional theory (DFT) calculations indicate that the synergistic effects of optimal pore environments and host–guest interactions from the naphthalene ring are pivotal in significantly enhancing the Bz adsorption capacity and Bz/Cy selectivity of DZU-73. This work highlights that linker engineering in mixed-ligand MOFs is a powerful strategy for tuning the Bz adsorption and Bz/Cy separation.