Photothermal-Responsive Microporous Nanosheets Confined Ionic Liquid for Efficient CO2 Separation

2D materials hold promising potential for novel gas separation. However, a lack of in-plane pores and the randomly stacked interplane channels of these membranes still hinder their separation performance. In this work, ferrocene based-MOFs (Zr-Fc MOF) nanosheets, which contain abundant of in-plane micropores, are synthesized as porous supports to fabricate Zr-Fc MOF supported ionic liquid membrane (Zr-Fc-SILM) for highly efficient CO₂ separation. The micropores of Zr-Fc MOF nanosheets not only provide extra paths for CO₂ transportation, and thus increase its permeance up to 145.15 GPU, but also endow the Zr-Fc-SILM with high selectivity (216.9) of CO₂ /N₂ through the nanoconfinement effect, which is almost ten times higher than common porous polymer SILM. Furthermore, based on the photothermal-responsive properties of Zr-Fc MOF, the performance is further enhanced (35%) by light irradiation through a photothermal heating process. This provides a brand new way to design light facilitating gas separation membranes.

Non-precious molybdenum nanospheres as a novel cocatalyst for full-spectrum-driven photocatalytic CO2 reforming to CH4

Photocatalytic CO₂ reforming is considered to be an effective method for clean, low-cost, and environmentally friendly reduction and conversion of CO₂ into hydrocarbon fuels by utilizing solar energy. However, the low separation efficiency of charge carriers and deficient reactive sites have severely hampered the efficiency of the photocatalytic CO₂ reforming process. Therefore, cocatalysts are usually loaded onto the surface of semiconductor photocatalysts to reduce the recombination of charge carriers and accelerate the rates of surface reactions. Herein, molybdenum (Mo) nanospheres are proposed as a novel non-precious cocatalyst to enhance the photocatalytic CO₂ reforming of g-C₃N₄ significantly. The Mo nanospheres boost the adsorption of CO₂ and activate the surface CO₂via a photothermal effect. The time-resolved fluorescence decay spectra reveals that the lifetime of photo-induced charge carriers is prolonged by the Mo nanospheres, which guarantees the migration of charge carriers from g-C₃N₄ to Mo nanospheres. Unexpectedly, Mo loaded g-C₃N₄ can effectively utilize a wide spectral range from UV to near-infrared region (NIR, up to 800 nm). These findings highlight the potential of Mo nanospheres as a novel cocatalyst for photocatalytic CO₂ reforming to CH₄.

One Stone Two Birds: Zr-Fc Metal-Organic Framework Nanosheet for Synergistic Photothermal and Chemodynamic Cancer Therapy

Metal-organic frameworks (MOFs) have been identified as promising materials for the delivery of therapeutics to cure cancer owing to their intrinsic porous structure. However, in a majority of cases, MOFs act as only a delivery cargo for anticancer drugs while little attention has been focused on the utilization of their intriguing physical and chemical properties for potential anticancer purposes. Herein for the first time, an ultrathin (16.4 nm thick) ferrocene-based MOF (Zr-Fc MOF) nanosheet has been synthesized for synergistic photothermal therapy (PTT) and Fenton reaction-based chemodynamic (CDT) therapy to cure cancer without additional drugs. The Zr-Fc MOF nanosheet acts not only as an excellent photothermal agent with a prominent photothermal conversion efficiency of 53% at 808 nm but also as an efficient Fenton catalyst to promote the conversion of H₂O₂ into hydroxyl radical (^•OH). As a consequence, an excellent therapeutic performance has been achieved in vitro as well as in vivo through this combinational effect. This work aims to construct an "all-in-one" MOF nanoplatform for PTT and CDT treatments without incorporating any additional therapeutics, which may launch a new era in the investigation of MOF-based synergistic therapy platforms for cancer therapy.

Challenges and future perspectives on microwave absorption based on two-dimensional materials and structures

The widespread use of electronic equipment, such as computers, cell phones, communication devices and wireless facilities, has increased electromagnetic radiation, which can cause cancer and other diseases in humans. Furthermore, there is an urgent need for excluding the interferences in the aircraft and other precise instruments in military aspects. Therefore, minimizing and attenuating electromagnetic waves are critical issues. In this review, various two-dimensional (2D) materials and structures are discussed for microwave-absorbing and shielding in terms of 'thin, light, wide, and strong' requirements. The typical absorption and attenuation mechanisms are analysed and summarized to deliver an overall view and offer possible trends for future developments. Multiple works have revealed that 2D materials and structures are promising for use in microwave devices. In addition to conventional materials with 2D structures, we focus on new graphene-like materials, such as 2D transition metal dichalcogenides and black phosphorus, due to their beneficial absorbing and shielding properties. These 2D materials will likely play an important role in electromagnetic wave absorption and cancellation in the future. Finally, the related challenges and some new 2D materials are briefly discussed.

Anisotropic fluoride nanocrystals modulated by facet-specific passivation and their disordered surfaces

Rutile-type fluorides have been proven to be active components in the context of emerging antiferr-omagnetic devices. However, controlled synthesis of low-dimensional, in particular two-dimensional (2D), fluorides in a predictable and deterministic manner remains unrealized because of a lack of efficient anisotropic control, which impedes their further development in reduced dimensions. We report here that altered passivation of {110} growing facets can direct the synthesis of rutile-type fluoride nanocrystals into well-defined zero-dimensional (0D) particulates, one-dimensional (1D) rods and 2D sheets in a colloidal approach. The obtained nanocrystals show positive exchange bias and enhanced magnetic transition temperature from the coexistence of long-range antiferromagnetic order and disordered surface spins, making them strong alternatives for flexible magnetic devices and sensors.

Facilitate Gas Transport through Metal-Organic Polyhedra Constructed Porous Liquid Membrane

Type II porous liquids are demonstrated to be promise porous materials. However, the category of porous hosts is very limited. Here, a porous host metal-organic polyhedra (MOP-18) is reported to construct type II porous liquids. MOP-18 is dissolved into 15-crown-5 as an individual cage (5 nm). Both the molecular dynamics simulations and experimental gravimetric CO₂ solubility test indicate that the inner cavity of MOP-18 in porous liquids is unoccupied by 15-crown-5 and is accessible to CO₂ . Thus, the prepared porous liquids show enhanced gas solubility. Furthermore, the prepared porous liquid is encapsulated into graphene oxide (GO) nanoslits to form a GO-supported porous liquid membrane (GO-SPLM). Owing to the empty cavity of MOP-18 unit cages in porous liquids that reduces the gas diffusion barrier, GO-SPLM significantly enhances the permeability of gas.

Excellent thermoelectric performance induced by interface effect in MoS2/MoSe2 van der Waals heterostructure

Herein, thermoelectric properties of MoS₂/MoSe₂ lateral and van der Waals heterostructure are investigated by using density functional theory calculations and non-equilibrium Green's function method. Compared with pure MoS₂, the thermoelectric performance of MoS₂/MoSe₂ lateral heterostructure is significantly improved due to the sharply decreased thermal conductance and slightly reduced power factor. Moreover, the thermoelectric performance can be further improved by constructing MoS₂/MoSe₂ van der Waals heterostructure. The room temperature ZT can reach 3.5, which is about 3 and 6 times greater than MoS₂/MoSe₂ lateral heterostructure and pure MoS₂, respectively. This is because the strongly local electron and phonon states result in an ultralow thermal conductance in MoS₂/MoSe₂ van der Waals heterostructure. Furthermore, we also find that the thermoelectric performance of MoS₂/MoSe₂ van der Waals heterostructure is insensitive to contact areas due to the competing influence of PF and total thermal conductance. The current study presents an effective strategy to improve the thermoelectric performance of 2D heterostructures, which can be extended to a variety of materials for different applications.

Ce-Doped Graphitic Carbon Nitride Derived from Metal Organic Frameworks as a Visible Light-Responsive Photocatalyst for H2 Production

Novel fibrous graphitic carbon nitride (g-C₃N₄) derivatives prepared from metal organic frameworks (MOFs) were doped with Ce³⁺ (Ce-C₃N₄) as photocatalytic materials. Ce-C₃N₄ was characterized using various techniques, revealing its high specific surface area, excellent photocatalytic activity, and stability for H₂ evolution under visible light irradiation. The fluorine modified samples show superior photocatalytic activity under visible light irradiation, which is due to the presence of more active sites and enhanced absorption of solar energy. This work provides a new synthetic route for MOF-derived g-C₃N₄ that can be doped with different metal ions. The fluorine modified Ce-C₃N₄ is an efficient photocatalyst with potential for many applications related to energy and the environment.

Accelerating oxygen evolution electrocatalysis of two-dimensional NiFe layered double hydroxide nanosheets via space-confined amorphization

NiFe layered double hydroxides (LDHs) have received widespread attention due to their unique structures and inherent electrocatalytic activity towards the oxygen evolution reaction (OER). Extensive studies have been reported to further improve the electrocatalytic activity of NiFe-LDHs via various strategies. However, controlling the degree of amorphization and stabilizing the amorphous zone during the electrocatalytic process are still challenging. Here, we report a facile method to synthesize a space-confined amorphous NiFe-LDH (SCA-NiFe-LDH) by selectively etching the surfaces of electrocatalysts. Due to the successful anchoring of amorphous zones onto the basal planes of the two-dimensional NiFe-LDH, the optimized SCA-NiFe-LDH exhibits high electrocatalytic activity with a low overpotential of 190 mV at 10 mA cm^-2, a Tafel slope of 31 mV dec^-1 and excellent long-term stability. The substantially enhanced OER performance is attributed to the increased amount of active sites and the modified electronic structure of NiFe-LDH after amorphization.

Enhanced Photocatalytic CO2 Reduction in Defect-Engineered Z-Scheme WO3-x /g-C3N4 Heterostructures

Oxygen vacancy-modified WO_3-x nanorods composited with g-C₃N₄ have been synthesized via the chemisorption method. The crystalline structure, morphology, composition, band structure, and charge separation mechanism for WO_3-x /g-C₃N₄ heterostructures are studied in detail. The g-C₃N₄ nanosheets are attached on the surface of WO_3-x nanorods. The Z-scheme separation is confirmed by the analysis of generated hydroxyl radicals. The electrons in the lowest unoccupied molecular orbital of g-C₃N₄ and the holes in the valence band of WO₃ can participate in the photocatalytic reaction to reduce CO₂ into CO. New energy levels of oxygen vacancies are formed in the band gap of WO₃, further extending the visible-light response, separating the charge carriers in Z-scheme and prolonging the lifetime of electrons. Therefore, the WO_3-x /g-C₃N₄ heterostructures exhibit much higher photocatalytic activity than the pristine g-C₃N₄.

FeSe2/carbon nanotube hybrid lithium-ion battery for harvesting energy from triboelectric nanogenerators

FeSe2-carbon nanotube (FeSe2-CNT) hybrid microspheres are investigated as anode materials for lithium ion batteries (LIBs), exhibiting a high specific capacity of 571.2 mA h g-1 at 0.5 A g-1 with excellent rate performance and cycling stability. The FeSe2-CNT hybrid LIBs could withstand the high-voltage pulse of triboelectric nanogenerators (TENGs) and be charged by TENGs directly for harvesting energy with high stability.

Intrinsic Van Der Waals Magnetic Materials from Bulk to the 2D Limit: New Frontiers of Spintronics

2D van der Waals (vdW) magnets, which present intrinsic ferromagnetic/antiferromagnetic ground states at finite temperatures down to atomic-layer thicknesses, open a new horizon in materials science and enable the potential development of new spin-related applications. The layered structure of vdW magnets facilitates their atomic-layer cleavability and magnetic anisotropy, which counteracts spin fluctuations, thereby providing an ideal platform for theoretically and experimentally exploring magnetic phase transitions in the 2D limit. With reduced dimensions, the susceptibility of 2D magnets to a large variety of external stimuli also makes them more promising than their bulk counterpart in various device applications. Here, the current status of characterization and tuning of the magnetic properties of 2D vdW magnets, particularly the atomic-layer thickness, is presented. Various state-of-the-art optical and electrical techniques have been applied to reveal the magnetic states of 2D vdW magnets. Other emerging 2D vdW magnets and future perspectives on the stacking strategy are also given; it is believed that they will excite more intensive research and provide unprecedented opportunities in the field of spintronics.

Integrated System of Solar Cells with Hierarchical NiCo2O4 Battery-Supercapacitor Hybrid Devices for Self-Driving Light-Emitting Diodes

An integrated system has been provided with a-Si/H solar cells as energy conversion device, NiCo₂O₄ battery-supercapacitor hybrid (BSH) as energy storage device, and light emitting diodes (LEDs) as energy utilization device. By designing three-dimensional hierarchical NiCo₂O₄ arrays as faradic electrode, with capacitive electrode of active carbon (AC), BSHs were assembled with energy density of 16.6 Wh kg^-1, power density of 7285 W kg^-1, long-term stability with 100% retention after 15,000 cycles, and rather low self-discharge. The NiCo₂O₄//AC BSH was charged to 1.6 V in 1 s by solar cells and acted as reliable sources for powering LEDs. The integrated system is rational for operation, having an overall efficiency of 8.1% with storage efficiency of 74.24%. The integrated system demonstrates a stable solar power conversion, outstanding energy storage behavior, and reliable light emitting. Our study offers a precious strategy to design a self-driven integrated system for highly efficient energy utilization.

[Risk factors and prognoses analysis of new-onset atrial fibrillation in patients with acute myocardial infarction]

Objective: To explore the risk factors and prognoses of new-onset atrial fibrillation (NOAF) in patients with acute myocardial infarction (AMI). Methods: A total of 468 patients with AMI were admitted into Beijing Anzhen Hospital for emergency pereutaneous coronary intervention (PCI). According to the NOAF occurred during hospitalization, the patients were divided into two groups: the NOAF (n=37) group and the non-NOAF (n=431) group. Parameters including general clinical conditions, coronary lesions, echocardiography, biochemical markers, C-reactive protein (CRP) , N-terminal pro-brain natriuretic peptide (NT-pro-BNP), and myocardial markers were collected. In-hospital mortality and incidence of in-hospital main adverse cardiovascular and cerebrovascular events (MACCE) were compared between the two groups. Logistic multivariate regression analyses were performed for the association between the risk factors and NOAF. Results: The incidence of NOAF was 7.9% in AMI patients undergoing emergency PCI. There were no significant differences in door-to-balloon time, weight, platelet counts, baseline serum creatinine (SCr), postoperative SCr, triglyceride, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, uric acid, glycosylated hemoglobin A1c, preoperative medication, number of lesions, thrombus aspiration, location of myocardial infarction, and history of hypertension, diabetes, peripheral vascular disease and old myocardial infarction between the two groups. The percentage of women was in the NOAF group (32.4% vs. 16.7%, P<0.05) and subjects in this group were significantly elder than those in the non-NOAF groups [(66±10) years vs. (571±11) years, P<0.001]. Moreover, the levels of no-reflow rate (40.5% vs. 12.6%, P<0.001) , CRP [25.2 (15.43, 29.97) mg/L vs.5.21 (2.33, 16.98) mg/L, P<0.001], white blood cell counts [(11.19±3.44)×10(9) vs. (9.91±3.23)×10(9), P=0.022], NT-pro-BNP [(652.6±108.8) ng/L vs. (258.3±105.9) ng/L, P<0.001], and troponin I (TnI) [20.41(1.78, 87.89) μg/L vs.7.72(1.29, 36.39) μg/L, P=0.006] were significantly higher in the NOAF group than in the non-NOAF group, while left ventricular ejection fraction [(47.70±7.34)% vs. (53.35±8.05)%, P<0.001], and hemoglobin [137.0(125.5, 146.0) g/L vs.144.0(133.0,156.0) g/L, P=0.042] were significantly lower in the NOAF group than the non-NOAF group. Patients in the NOAF group had significantly longer hospital stay than those in the non-NOAF group [(8.7±5.6) d vs. (6.0±2.3) d, P=0.007]. The in-hospital mortality (8.1% vs 1.4% P=0.004) and the incidence of in-hospital MACCE (37.8% vs. 7.7%, P<0.001) in the NOAF group were significantly higher than those in the non-NOAF group. Logistic multivariate regression analyses showed that age (HR 1.083, 95%CI 1.028-1.141, P=0.003), CRP (HR 1.116, 95%CI 1.049-1.187, P=0.001), NT-pro-BNP (HR 1.463, 95%CI 1.001-4.064, P=0.001) and no-reflow (HR 4.388, 95%CI 1.006-19.144, P=0.049) were independent predictors of NOAF after AMI. Conclusions: Age, elevated levels of CRP, NT-pro-BNP, and the absence of no-reflow are risk factors for incident NOAF in patients with AMI in hospital.

Magnetic orders and origin of exchange bias in Co clusters embedded oxide nanocomposite films

Magnetic nanoparticles embedded oxide semiconductors are interesting candidates for spintronics in view of combining ferromagnetic (FM) and semiconducting properties. In this work, Co-ZnO and Co-V₂O₃ nanocomposite thin films are synthesized by Co ion implantation in crystalline thin films. Magnetic orders vary with the implantation fluence in Co-ZnO, where superparamagnetic (SPM) order appears in the low-fluence films (2  ×  10¹⁶ and 4  ×  10¹⁶ ions cm^-2) and FM order co-exists with the SPM phase in high-fluence films (1  ×  10¹⁷ ions cm^-2). Exchange bias (EB) appears in the high-fluence films, with an EB field of about 100 Oe at 2 K and a blocking temperature of around 100 K. On the other hand, Co-V₂O₃ thin films with an implantation fluence of 3.5  ×  10¹⁶ ions cm^-2 exhibit a clear antiferromagnetic (AFM) coupling at low temperatures without the EB effect. The different magnetic behavior of the Co-implanted films with different Co content leads us to conclude that the observed EB effect in the Co-ZnO films results from the FM/AFM coupling between sizable Co nanoparticles and their CoO/Co₃O₄ surroundings in the (Zn,Co)O matrix. On the other hand, the absence of EB effect in Co-V₂O₃ appears to be due to the small size of the FM Co nanoparticles in spite of an AFM magnetic order. Detailed studies of magnetic orders and EB effect in magnetic nanocomposite semiconductors can pave the way for their application in spintronics.

Cytological mechanism of astragaloside IV in promoting repair of bone defects

To explore the possible cytological mechanism underlying the role of Astragaloside IV in promoting the repair of bone defects, osteoblasts were cultured in vitro and identified using inverted phase contrast microscopy, alkaline phosphatase (ALP) staining and alizarin red staining.

Multifunctional Zn-Al layered double hydroxides for surface-enhanced Raman scattering and surface-enhanced infrared absorption

Surface-enhanced Raman scattering (SERS) and surface-enhanced infrared absorption (SEIRA) are complementary techniques, and both provide fingerprint structural information on various materials with a high sensitivity. Herein, Zn-Al layered double hydroxides (LDHs) are proposed for the first time as highly sensitive and uniform substrates for both SERS and SEIRA. Zn-Al LDHs show a remarkable SERS effect with an enhancement factor (EF) as high as 1.637 × 104 by using 4-mercaptobenzoic acid (4-MBA) as the probe molecule, where the charge transfer and hydrogen bonds are believed to result in the SERS effect. Interestingly, Zn-Al LDHs also exhibit SEIRA by using 4-methoxybenzenethiol (4-MTP), where the resultant substrates possess excellent long-term stability. This study not only presents a facile route to fabricate LDH materials, but also provides a novel substrate that can be used in both SERS and SEIRA.

Ferrocenecarboxylic acid: a functional modulator for UiO-66 synthesis and incorporation of Pd nanoparticles

FcCOOH was found to be an efficient modulator for UiO-66 synthesis and a functional group for incorporation of Pd nanoparticles.

Ferrocenyl metal–organic framework hollow microspheres for in situ loading palladium nanoparticles as a heterogeneous catalyst

Zn–Fc MOF hollow microspheres were prepared for the in situ reduction of Pd²⁺ into Pd nanoparticles as a highly efficient heterogeneous catalyst.

Improving the Visible-Light Photocatalytic Activity of Graphitic Carbon Nitride by Carbon Black Doping

Hydrogen production by water splitting and the removal of aqueous dyes by using a catalyst and solar energy are an ideal future energy source and useful for environmental protection. Graphitic carbon nitride can be used as the photocatalyst with visible light irradiation. However, it typically suffers from the high recombination of carriers and low electrical conductivity. Here, we have developed a facile mix-thermal strategy to prepare carbon black-modified graphitic carbon nitrides, which possess high electrical conductivity, a wide adsorption range of visible light, and a low recombination rate of carriers. With the help of carbon black, highly crystallized graphitic carbon nitrides with built-in triazine and heptazine heterojunctions are obtained. Improved photocatalytic activities have been achieved in carbon black-modified graphitic carbon nitride. The dye removal rate can be three times faster than that of pristine graphitic carbon nitride and the photocatalytic H₂ generation is 234 μmol h^-1 g^-1 under visible light irradiation.

Fabrication of ZnO/Red Phosphorus Heterostructure for Effective Photocatalytic H₂ Evolution from Water Splitting

Photocatalysis is a green technique that can convert solar energy to chemical energy, especially in H₂ production from water splitting. In this study, ZnO and red phosphorus (ZnO/RP) heterostructures were fabricated through a facile calcination method for the first time, which showed the considerable photocatalytic activity of H₂ evolution. The photocatalytic activities of heterostructures with different ratios of RP have been investigated in detail. Compared to bare ZnO, ZnO/RP heterostructures exhibit a 20.8-fold enhancement for H₂ production and furthermore overcome the photocorrosion issue of ZnO. The improved photocatalytic activities highly depend on the synergistic effect of the high migration efficiency of photo-induced electron–hole pairs with the inhibited charge carrier recombination on the surface. The presented strategy can also be applied to other semiconductors for various optoelectronics applications.

Stannous oxide promoted charge separation in rationally designed heterojunction photocatalysts with a controllable mechanism

Due to the sluggish mobility of holes, the low charge-separation rate remains an intrinsic issue that limits further increase of the photocatalytic conversion efficiency. Herein, we proposed an in situ hydrothermal method to expedite the charge transfer with enhanced photocatalytic H2 evolution rate and photodegradation activities via introducing SnO microplates into TiO2. As compared to bare TiO2, the SnO/TiO2 heterojunction achieves remarkable 470% and 150% higher efficiency for the photocatalytic H2 evolution rate and photodegradation of rhodamine B, respectively. In particular, it is demonstrated that the charge transfer mechanism of SnO/TiO2 can be switched from the Z-scheme to type II by Pt loading, leading to a significant enhancement of photocatalytic performances. Furthermore, the photocatalytic H2 evolution activities of ZnO and C3N4 can also be improved by introducing SnO via simple mechanical mixing. This work provides not only a new versatile stimulant for enhancing photocatalytic activities but also in-depth understanding of the charge transfer mechanism of heterointerfaces of semiconductors.

Defect-Induced Exchange Bias in a Single SrRuO3 Layer

Exchange bias stems from the interaction between different magnetic phases, and therefore, it generally occurs in magnetic multilayers. Here, we present a large exchange bias in a single SrRuO₃ layer induced by helium ion irradiation. When the fluence increases, the induced defects not only suppress the magnetization and the Curie temperature but also drive a metal-insulator transition at a low temperature. In particular, a large exchange bias field up to ∼0.36 T can be created by the irradiation. This large exchange bias is related to the coexistence of different magnetic and structural phases that are introduced by embedded defects. Our work demonstrates that spintronic properties in complex oxides can be created and enhanced by applying ion irradiation.