Search

One of the existing challenges while realizing miniaturization of the antenna is ensuring that the performance of the antenna without any negative effect has become the main focus of many researchers and pose challenges towards microstrip antenna research. In this paper, we focus on the study of miniaturization of microstrip antennas by designing miniaturized antennas, and carry out modeling and simulation. On basis of existing theory, the proposed method introduces the miniaturization technology of three mainstream microstrip antennas, namely meandering, loading, and bending slots. The electromagnetic simulation software HFSS is used to analyze the influence of the parameters of the three technologies on the antenna performance, and respectively propose a miniaturization scheme of the microstrip antenna.

Benefiting from the introduction of V and high-valency Mo for modulation of the electronic structure to obtain a Ni3+-rich microenvironment, a novel Ni3+-rich electrocatalyst achieves excellent OER performance.

Realizing precise temperature regulation under low constant near-infrared (NIR) laser density is of great significance for the clinical application of photothermal therapy. However, the photo-modulated photothermal conversion materials are still...

The rational design of high-efficiency electrocatalysts for application in water oxidation in alkaline media remains a great challenge. In this paper, Ni

Sodium-ion hybrid capacitors are emerging as promising energy storage and power output devices. However, they suffer from a sluggish faradaic reaction of the anode and low capacity of the cathode. Zeolite-templated carbons are a distinct class of ordered microporous carbon material, which have the characteristic properties related to electrochemical performance. Herein, we design two types of ordered microporous carbon (OMC) as the cathode and anode, which occupy different potential regions, through in situ heterostructure regulation for sodium-ion hybrid capacitors. The OMC has a relatively high graphite degree and expanded interlayer spacing, which can facilitate the storage of sodium ions as the anode. And nitrogen atoms are doped into the OMC framework to achieve nitrogen-doped ordered microporous carbon (N-OMC) as the cathode. The N-OMC not only has electric double layer capacity, but also has pseudocapacitive storage as a result of nitrogen doping. The resulting sodium-ion hybrid capacitor coupling two types of OMC achieves a high energy density of 119 W h kg−1, high power density of 5807 W kg−1, low capacity decay of 0.015% per cycle after 1800 cycles, and low self-discharge rate between 0.0 and 4.0 V. This result offers a feasible way to achieve electrodes derived from the same precursor and the fabrication of high-performance hybrid capacitors.

All-inorganic CsPbX3 (X = Cl, Br and I) nanocrystals (NCs) receive great attention for their multi-functional applications. Here, we propose a facile two-step in situ strategy to encapsulate CsPbX3 (X = Cl, Br and I) NCs in the interrupted structure of the hierarchical titanium silicate-1 (TS-1) molecular sieve, which involves the Cs+-TPA+ (tetrapropylammonium ion) ion exchange process and a subsequent solution reaction with a PbX2-containing organic solution to afford the formation of highly stable luminescent CsPbX3-TS nanocomposites. Interestingly, the as-obtained CsPbBr3-TS nanocomposite exhibits remarkable dual-mode temperature-readout optical thermometric properties involving a linear response in the fluorescence intensity and a blue-shift of the CsPbBr3 emission. The CsPbBr3-TS composite also demonstrates excellent luminescent stability in various polar solvents, while the fluorescence color of CsPbCl3-TS, CsPbCl1.5Br1.5-TS, CsPbBr1.5I1.5-TS, and CsPbBrI2-TS nanocomposites turn to blue (410–420 nm) when exposed to strongly polar molecules of acetone, ethanol, and water, ascribing to the hydrogen bonding effect between the surface –NH2 group in CsPbX3 and carbonyl (–CO) and hydroxyl (–OH) groups contained in solvents. The space confinement and various stabilities of CsPbX3 (X = Cl, Br and I)-TS nanocomposites afford them great potential in multi-functional application fields, including temperature sensing, fingerprint identification, anti-counterfeiting and security protection.

Despite the fact that electrocatalysis has made great achievement, it is a challenge to design/fabricate efficient and low-cost electrocatalysts for the generation of hydrogen and oxygen through overall water splitting. Here, flocculent VS nanoparticle aggregate-modified NiCo2S4 nanograss arrays grown on a nickel foam (denoted as VS/NiCo2S4/NF) were fabricated via a hydrothermal method, and were applied as electrodes for overall water splitting. Clearly, the introduction of VS nanoparticle aggregates could modify the electronic structure and offer rich active sites. Moreover, strong electronic interactions between the interfaces of the flocculent VS nanoparticle aggregates and NiCo2S4 nanograss arrays could improve the conductivity and charge transfer capability. Thus, the as-prepared VS/NiCo2S4/NF exhibits outstanding electrocatalytic activity with overpotentials of 332 mV for OER at the current density of 50 mA cm−2 and 187 mV for HER at the current density of 10 mA cm−2 in a 1 M KOH electrolyte, being superior to most of the previously reported Ni/Co-based sulfide electrocatalysts. Besides, the two-electrode system consists of VS/NiCo2S4/NF for overall water splitting under alkaline conditions, and it requires 1.87 V to attain 50 mA cm−2, and maintains this activity for at least 24 h. Our findings could provide an opportunity for the rational design of highly efficient bifunctional composite electrocatalysts towards water splitting.

The three-dimensional porous structure of a material can trap the propagating electromagnetic waves by multiple reflections and scatterings, thereby improving the microwave absorption properties. The highly ordered and interconnected porous NaY zeolites can serve as the templates to prepare the three-dimensional graphene (3DG). A high defect density of 13.4–23.7 × 1010 cm−2 was obtained in the 3DG due to the incomplete replication. Simultaneously, the broken asymmetry of space charges in the defect sites will lead to the separation of space charges and the formation of electric dipoles, which results in significantly enhanced dielectric performance and microwave absorption. Consequently, owing to the porous structure and high specific surface area, the effective absorption band of the 3DG attains a large width of 14.3 GHz (3.7–18 GHz) with the absorber thicknesses located in 2–5 mm. The microwave absorption performance of 3DG is much superior to that of multilayer graphene with a two-dimensional structure. Hence, this ultralight 3DG can act as a promising microwave absorption material and probably gifts other physical applications in the future.

Quantum teleportation is an important method for transmitting quantum states between two quantum communication nodes. In this paper, we propose a low-latency quantum communication scheme based on Greenberger-Horne-Zeilinger (GHZ) state. To implement two-qubit transmission, the source and all intermediate nodes perform quantum measurements simultaneously and the measurement results are transmitted to the destination node through classical channel independently. The destination node performs appropriate unitary operation on its particles to recover the original two-qubit state based on received measurement results. Our scheme effectively reduces the end-to-end quantum communication delay.

Controlled synthesis of rare-earth metal-organic frameworks (RE-MOFs) is of great significance to match their emerging multifunctional luminescence applications. Herein, we propose a green and general solvent-free synthetic strategy for the adjustment of morphology and dimension of various RE-MOFs (RE = Eu, Tb, Er, Dy, Y, Tm) by using a tetraethylammonium bromide-assisted thermal-heating method. These self-assembled RE-MOF materials possess controllable morphologies and hierarchical structures while retaining the structural topology of MIL-78, proving that the strategy is a feasible and effective way in opening up large-scale synthesis of RE-MOFs. It is further found that the tetraethylammonium could be carbonized into carbon dots and encapsulated in Eu/Tb-MIL-78 to enhance the fluorescence emission intensities significantly, making the hierarchical Eu/Tb-MIL-78 MOF materials good candidates for the latent fingerprints recognition application. This work provides a novel strategy for effectively controlling the morphology and dimension of RE-MOFs materials with enhanced photoluminescence and has great potential in their scaling-up syntheses and exploring the new luminescence applications.

In this paper, Ag-based g-C3N4 composites have been successfully fabricated through two deferent synthetic methods: (i) a facile and efficient precipitation-calcination strategy (denoted as D–CN–xAg, x represents the dosage of Ag2CO3, the same below), (ii) a calcination method (denoted as Z–CN–xAg). All Ag-based g-C3N4 composites exhibit the enhanced photocatalytic activities under visible-light irradiation. Moreover, the optimal dosage of Ag2CO3 in the D–CN–xAg composite is found to be 5%, the corresponding hydrogen production capacity is 153.33 μmol g−1 h−1, which is 4.6 times higher than that of Z–CN–5%Ag composite. This might be attributed to appropriate content of metallic Ag and more active sites exposed on the surface of D–CN–5%Ag composite. Meanwhile, combining with photoelectrochemical results, it could be inferred that LSPR effect and the intimate interfacial between metallic Ag and g-C3N4 in the system play also important role for the improvement of photocatalytic activity. These results demonstrate that the appropriate loading of metallic Ag originated from Ag2CO3 into g-C3N4 could accelerate the separation and transfer of photogenerated electron-hole pairs, leading to the improvement of photocatalytic activity for hydrogen production from water splitting. Finally, a possible photocatalytic mechanism is proposed.

MXene is a rising star of two-dimensional (2D) materials for energy relative applications, however, the traditional synthesis of MXene etched by hazard HF acid or LiF+HCl mixed solution is highly dangerous with the risk of splashing or pouring liquid solutions. In this work, we developed a water-free ionothermal synthesis of 2D Ti3C2 MXene via etching pristine Ti3AlC2 MAX in low-cost choline chloride and oxalic acid based deep eutectic solvents (DES) with the presence of NH4F, thus it was highly safe and convenient to operate solid precursor and product materials at room temperature. Benefited from the low vapor pressure and solvating properties of DES, the prepared Ti3C2 (denoted as DES-Ti3C2) possessed a high purity up to 98% compared with 95% for HF etched Ti3C2 (denoted as HF-Ti3C2). Notably, an expanded interlayer spacing of 1.35 nm could be achieved due to the intercalation of choline cations in DES-Ti3C2, larger than that of HF-Ti3C2 (0.98 nm). As a result, the DES-Ti3C2 anodes exhibited enhanced lithium storage performance, such as high reversible capacity of 208 mAh g−1 at 0.5 A g−1, and long cycle life over 400 times, outperforming most reported pure MXene anodes. The ionothermal synthesis of MXene developed here may pave a new way to safely prepare other MXene for various energy relating applications.

Multicomponent spinel ferrites are essential to be used in high-performance gas-sensing materials. Herein, multinary (Cu,Zn)Fe2O4 spinel nano-microspheres with tunable internal structures, including solid, core–shell, and yolk–shell, were successfully synthesized by a simple self-templated solvothermal method combined with a subsequent annealing strategy. The internal structures of the (Cu,Zn)Fe2O4 nano-microspheres significantly rely on the heating rates of the precursors, which show promising selective response towards trimethylamine gas. Among them, the as-formed yolk–shell (Cu,Zn)Fe2O4 nano-microspheres exhibited high response to triethylamine with excellent selectivity of STEA/SX = 1.86 at 160 °C, fast response–recovery rate (58 s/136 s), and long-term repeatability and stability of more than one month. The corresponding triethylamine gas-sensing mechanism with the special microstructures is discussed. This work provides new insights into the rational design of interior structure and the modulation of high gas response and selectivity of multinary spinel ferrites in gas-sensing applications.

Developing a highly reliable non-contact optical thermometer probe with excellent sensitivity and multi-mode temperature sensing behaviours is always a great challenge. Here, dual-emitting luminescent composites fabricated using a europium-based metal–organic framework (Eu-MOF) and surface-immobilized molecular dye (Coumarin 7) were successfully prepared by a simple solvothermal method, followed by a post-modification strategy. Benefiting from the linear response in fluorescence intensity ratios (FIRs) of Eu3+ to Coumarin 7 dye molecules in the temperature range from 10 °C to 90 °C, the composite demonstrated the maximum relative temperature sensitivity (Sr) of 0.50% °C−1 at 90 °C. Moreover, the observed red-shift of Coumarin 7 emission with the temperature readout suggests a dual-mode optical thermal sensing mechanism in the dye-immobilized MOF composite. Their excellent reusability and temperature sensing mechanisms have been also investigated. These results demonstrate the potential of the Coumarin 7 functionalized Eu-MOF composite as a dual-mode optical thermometer for temperature sensing applications.

Growing interest in photochromic materials has largely stimulated researchers in this field to synthesize inorganic–organic materials that are composed of photochromic molecules such as viologen derivatives, naphthalene diimide (NDI) derivatives, and diarylethene derivatives. However, the requirement of an elaborate structural design, complicated synthesis, and high cost remain the issues that need to be addressed before the photochromic materials can be accepted by the market. Their synthesis using low-cost deep-eutectic solvents (DESs) may offer new opportunities to provide cost-effective reaction routes for large-scale synthesis of photochromic materials. We present a multifunctional photochromic inorganic–organic complex |C10H10N2|[GaF(C2O4)2], which is constructed from a nonphotochromic 4,4′-bipyridine ligand and oxalate derived from low-cost DES components. The complex exhibits intriguing photochromic behavior with a wide range of photo-response from UV to visible light and an ultralong-lived charge-separated state. Moreover, it possesses unprecedented tunable photocurrent responses and photocatalytic properties.

Continuous monitoring of physical motion, which can be successfully achieved via a wireless flexible wearable electronic device, is essential for people to ensure the appropriate level of exercise. Currently, most of the flexible LC pressure sensors have low sensitivity because of the high Young’s modulus of the dielectric properties (such as PDMS) and the inflexible polymer films (as the substrate of the sensors), which don’t have excellent stretchability to conform to arbitrarily curved and moving surfaces such as joints. In the LC sensing system, the metal rings, as the traditional readout device, are difficult to meet the needs of the portable readout device for the integrated and planar readout antenna. In order to improve the pressure sensitivity of the sensor, the Ecoflex microcolumn used as the dielectric of the capacitive pressure sensor was prepared by using a metal mold copying method. The Ecoflex elastomer substrates enhanced the levels of conformability, which offered improved capabilities to establish intimate contact with the curved and moving surfaces of the skin. The pressure was applied to the sensor by weights, and the resonance frequency curves of the sensor under different pressures were obtained by the readout device connected to the vector network analyzer. The experimental results show that resonant frequency decreases linearly with the increase of applied pressure in a range of 0–23,760 Pa with a high sensitivity of −2.2 MHz/KPa. We designed a coplanar waveguide-fed monopole antenna used to read the information of the LC sensor, which has the potential to be integrated with RF signal processing circuits as a portable readout device and a higher vertical readout distance (up to 4 cm) than the copper ring. The flexible LC pressure sensor can be attached to the skin conformally and is sensitive to limb bending and facial muscle movements. Therefore, it has the potential to be integrated as a body sensor network that can be used to monitor physical motion.

The catalytic hydrogenation of CO2 to methane as a promising solution for the utilization of CO2 has aroused intensive attention based on the viewpoints of sustainable use of energy and environment...

A novel three-dimensional open-framework titanophosphite Ti(HPO3)2 (denoted as JIS-15) has been ionothermally synthesized. JIS-15 possesses photovoltaic properties as an n-type semiconductor and exhibits remarkable photocatalytic activity for the degradation of rhodamine B (RhB) under visible light irradiation.

Template-controlled syntheses via metal–organic frameworks (MOFs) have emerged as a general strategy to fabricate metal oxides with tailored porous structures. Here, novel hierarchical SnO2/α-Fe2O3 hollow microcubes have been obtained by post-loading of Sn2+ ions on the surface of Fe4(Fe(CN)6)3 microcubes and a subsequent thermolysis route. The as-formed hierarchical SnO2/α-Fe2O3 composites exhibit remarkable selective acetone-sensing properties, in which the optimum composition of SnO2/α-Fe2O3 with Sn : Fe = 1.5 exhibits the best response towards 200 ppm acetone gas under the operating temperature of 270 °C (with gas response Ra/Rg = 9.3), with a fast response/recovery speed (6 s/7 s), as well as excellent reproducibility for at least 15 days without a significant change in response. The applied strategy provides a general and controllable method to access other hierarchically structured multi-metal oxide architectures with intriguing morphologies and adjustable sensing properties.

Hierarchically spinel Ni x Co 1- x Fe 2 O 4 (0.0 ≤ x ≤ 0.5) microcubes were successfully prepared through a combined solvent evaporation strategy and morphology-inherited annealing treatment. By using the Fe-based metal-organic frameworks (MOFs), Fe 4 (Fe(CN) 6 ) 3 , and inorganic Ni 2+ and Co 2+ acetate salts as co-templated precursors, hierarchical Ni-doped spinel CoFe 2 O 4 architecture can be obtained, and the Ni/Co substitution ratios can be controlled systematically. The obtained cubic hierarchical Ni x Co 1- x Fe 2 O 4 , (0.0 ≤ x ≤ 0.5) composites presented highly acetone sensing properties, among which the Ni 0.1 Co 0.9 Fe 2 O 4 composite showed the strongest response performance (with gas response ( R g / R a ) of 1.67 at 240 °C) and excellent reproducibility (for at least 14 cycles), and the proposed acetone sensing mechanism was also discussed. The presented solvent evaporation and co-templated strategy may allow precisely access to fabricating other heteroatom doped inorganic materials with intriguing morphologies, architectures, chemical compositions and tunable sensing properties.

Multicomponent spinel ferrites are essential to be used in high-performance gas-sensing materials. Herein, multinary (Cu,Zn)Fe2O4 spinel nano-microspheres with tunable internal structures, including solid, core-shell, and yolk-shell, were successfully synthesized by a simple self-templated solvothermal method combined with a subsequent annealing strategy. The internal structures of the (Cu,Zn)Fe2O4 nano-microspheres significantly rely on the heating rates of the precursors, which show promising selective response towards trimethylamine gas. Among them, the as-formed yolk-shell (Cu,Zn)Fe2O4 nano-microspheres exhibited high response to triethylamine with excellent selectivity of STEA/SX = 1.86 at 160 °C, fast response-recovery rate (58 s/136 s), and long-term repeatability and stability of more than one month. The corresponding triethylamine gas-sensing mechanism with the special microstructures is discussed. This work provides new insights into the rational design of interior structure and the modulation of high gas response and selectivity of multinary spinel ferrites in gas-sensing applications.

Extended exposure to sunlight or artificial UV sources (particularly UVA and UVB) is a major cause of serious skin cancers and ocular diseases. A photochromic inorganic–organic complex was ionothermally synthesized via a decomposition-reassembly strategy, generated from a low-cost deep-eutectic solvent and a 4,4′-bipyridine system. Benefiting from the intrinsic synergy of the hydrogen bonding and π–π stacking interactions, the complex exhibited insensitivity towards visible light, outstanding color contrast from colorless to purple, rapid response time up to seconds, excellent reversibility and high thermal stability. UV index and UVB detection procedures indicated that the coloration performances of the complex exhibited a linear response towards UV index and UVB dose. Besides, the complex can be made to a portable test tablet, a freestanding mixed film with a cellulose paper and a mixed-matrix membrane with PVDF, which make it highly promising for portable and efficient visual UV index and detecting UVB dose.

Microwave absorbing materials are usually designed to solve electromagnetic impedance matching by compositing the magnetic and dielectric loss materials. Herein we demonstrated that the Mo@2D-MoS2 nanocomposites synthesized by arc-discharge method exhibit excellent microwave absorbility at gigahertz. Based on the transmission line theory, we prove quantitatively that more than 90% of the electromagnetic power can be attenuated at 5.6–18 GHz. The experimental results and theoretical analyses evidence that the heterogeneous interfaces and the few layers of the two-dimension graphene-like structures of Molybdenum disulfide (MoS2) contribute to the enhancement of the microwave absorption properties. The present study has important implications in understanding the microwave absorbing properties of the 2D materials and provides a new strategy for the design of variety microwave absorbers.

The rational design strategy to construct lanthanide ion functionalized metal organic frameworks (MOFs) has attracted tremendous attention as they are promising candidates for developing novel luminescence materials and optical sensors owing to their intense, long-lived and tunable luminescence performances. In this work, a series of Eu3+/Tb3+ singly doped or codoped bismuth-based MOFs were prepared under in situ facile solvothermal conditions using BiOBr nanoplates as bismuth resources. A red-green-blue-based trichromatic white-light emission can be finely achieved by modulating the doping ratio of Eu3+/Tb3+ in the blue-emitting Bi-MOF host material and such photoluminescence tuning can also be realized by controlling the excitation wavelength. In addition, the Eu3+/Tb3+ singly incorporated Bi-MOF can serve as a multifunctional fluorescent probe for sensing Fe3+ and Cr2O72- ions in aqueous solution, as well as small organic pollutants of acetone molecules, and their sensing mechanisms have also been analyzed. These lanthanide ion functionalized Bi-MOF materials exhibit great potential in exploring white-light emitting devices and construction of supersensitive multifunctional sensors.

Facile fabrication of new hybrids by post-modification approach is considered to be a straight forward strategy to develop new generation of chemosensor with high sensitivity and selectivity. In this work, a hybrid chemosensor prepared through surface modification of Zn2GeO4:Mn2+ nanorods by zeolitic imidazolate framework-8 (ZIF-8) is reported. Luminescent investigations revealed that the as-prepared Zn2GeO4:Mn2+@ZIF-8 heterostructure featured excellent sensing function with respect to temperature change from 298 K to 423 K, and Cu2+ ions concentration from 1 × 10−4 mol·L−1 to 1 × 10−1 mol·L−1. These results make Zn2GeO4:Mn2+@ZIF-8 composite superb candidate for luminescent applications in thermometers and metal ions detection.

We demonstrate a general strategy to design step by step the Ag nanoparticle-functionalized ZnO micro-flowers (Ag/ZnO composites). XRD patterns confirmed the presence of Ag nanoparticles in ZnO/Ag composites, and the SEM and TEM results further demonstrated that Ag nanoparticles were highly dispersed and anchored onto the surface of each ZnO nanosheets. By using the ZnO/Ag composites, the photodegradation of two herbicide derivatives, metamitron and metribuzin, were studied. The enhanced photocatalytic performance was ascribed to the fact that the Ag deposition could reduce the recombination probability of electron-hole pairs, and the photocatalytic mechanism were also investigated in this paper.

Herein, we present a facile strategy for the preparation of uniform ZnO/ZnFe2O4 hierarchical heterostructures using a Zn–Fe mixed metal–organic framework (Zn(Fe)-MOF) as a precursor via a calcination process. The phase structures, morphologies, and magnetic properties of the as-obtained ZnO/ZnFe2O4 heterostructures were characterized in detail by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM). The ZnO/ZnFe2O4 heterostructures obtained after calcination retained the special microsphere morphology of the Zn(Fe)-MOF, which was assembled from numerous flake-like nanosheets. When served as a photocatalyst for the degradation of rhodamine B (RhB) and methylene blue (MB) dyes in an aqueous solution, the ZnO/ZnFe2O4 heterostructures exhibited a relatively high catalytic performance and excellent resuability upon Xe lamp irradiation. Moreover, they can easily be seperated from the reaction system by an extra magnet; this suggests their potential application in water treatment. This study provides an effective route for the construction of novel multi-component photocatalysts with intriguing microstructures.

ZSM-5 catalysts with different morphologies were synthesized and evaluated for the catalytic conversion of furan in a fixed bed reactor to provide insights into the rational design of zeolite catalysts for catalytic fast pyrolysis (CFP). The effects of mesoporosity and morphology of ZSM-5 catalysts on the production of aromatics and olefins as well as catalyst deactivation were investigated. The results suggest that increasing mesoporosity and decreasing crystallite size can increase furan conversion and affect selectivity to products. Improved selectivities to benzene, toluene, xylene and olefins were achieved with mesoporous ZSM-5 and 100 nm ZSM-5 compared to 800 nm ZSM-5. Coke formation on zeolite catalysts during the reaction of furan was also largely reduced (up to 65%) by introducing mesoporosity. It was observed that coke is mainly formed and accumulated inside the micropores of ZSM-5 catalysts rather than on the external surface or within the mesopores. Characterization of mass transport in the coked zeolite samples using cyclohexane as a probe molecule suggested that coke blocks micropores, leading to a decrease in micropore volume during the catalyst deactivation process. However, due to the three-dimensional pore structure of ZSM-5, the mass transport properties of mesoporous ZSM-5 do not exhibit an apparent change. Catalyst deactivation was mainly due to the coverage of active sites by coke, rather than the blockage of the transport pathways by coke.

The rational design strategy to construct lanthanide ion functionalized metal organic frameworks (MOFs) has attracted tremendous attention as they are promising candidates for developing novel luminescence materials and optical sensors owing to their intense, long-lived and tunable luminescence performances. In this work, a series of Eu3+/Tb3+ singly doped or codoped bismuth-based MOFs were prepared under in situ facile solvothermal conditions using BiOBr nanoplates as bismuth resources. A red-green-blue-based trichromatic white-light emission can be finely achieved by modulating the doping ratio of Eu3+/Tb3+ in the blue-emitting Bi-MOF host material and such photoluminescence tuning can also be realized by controlling the excitation wavelength. In addition, the Eu3+/Tb3+ singly incorporated Bi-MOF can serve as a multifunctional fluorescent probe for sensing Fe3+ and Cr2O72- ions in aqueous solution, as well as small organic pollutants of acetone molecules, and their sensing mechanisms have also been analyzed. These lanthanide ion functionalized Bi-MOF materials exhibit great potential in exploring white-light emitting devices and construction of supersensitive multifunctional sensors.

Eu3+ doped β-NaGdF4 microcrystals were prepared by using an L-lysine-assisted hydrothermal synthetic method and the morphology evolution was successfully controlled. Hierarchical β-NaGdF4:Eu3+ microcrystals with different morphologies were obtained by changing the moles of L-lysine and the volume of H2O, respectively. The photoluminescence properties of the β-NaGdF4:Eu3+ samples with different morphology were comparatively discussed, in which the hollow hexagonal tube-like β-NaGdF4:Eu3+ exhibited the strongest fluorescence emission intensity owing to the high crystallinity. The characteristic luminescence properties of Tb3+-single doped, Yb3+/Er3+-, and Yb3+/Tm3+-codoped NaGdF4 microcrystals obtained in the presence of L-lysine under hydrothermal condition were also investigated. The superparamagnetic performance of β-NaGdF4:Eu3+ samples at 3 K were characterized in comparison to their paramagnetic property at 300 K, and the results indicated that all samples are paramagnetic at room temperature and the hollow tube-like β-NaGdF4:Eu3+ microcrystals exhibits best saturation magnetization values of 111.11 emu/g at 3 K. The results imply that the morphology-tunable β-NaGdF4:Eu3+ microcrystals are expected to have promising applications for micro/nano optical/magnetic functional devices.