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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.

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.

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.

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.

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.

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.

The catalytic performance of three-dimensionally ordered mesoporous imprinted (3DOm-i) zeolite catalysts with different frameworks (3DOm-i MFI, 3DOm-i BEA, and 3DOm-i LTA) were investigated by the liquid-phase catalytic conversion of benzyl alcohol in mesitylene and compared to that of other microporous and mesoporous catalysts with a high external surface area, which included MCM-22, 300 nm MFI, ITQ-2, and Al-MCM-41. The mesoporosity in MFI and BEA zeolites can effectively enhance the catalytic performance of the zeolite catalysts for benzyl alcohol self-etherification catalyzed by both the acid sites on the external and internal surface and the alkylation of mesitylene with benzyl alcohol catalyzed exclusively by the acid sites on the external surface. For 3DOm-i LTA, MCM-22, and Al-MCM-41, only the acid sites on the external surface can be utilized in the catalytic reactions. A distinct difference in the product selectivity was also observed for the microporous and mesoporous catalysts.

Hierarchical ZnxCd1-xS (x = 1, 0.85, 0.74, 0.64, 0.46 and 0.36) microclusters were successfully prepared by a secondary growth strategy using ethanol as solvent under solvothermal condition. Cluster-like ZIF-8 crystals derived from crystalline hierarchical zinc carbonate, CdCl2 inorganic salt and thiourea were used as the starting materials at stoichiometric ratios. The as-prepared hierarchical hierarchical Zn0.64Cd0.36S material exhibits excellent water splitting performance with a maximum H2 generation rate of 815 μmol g−1 h−1 under visible-light irradiation in the presence of sacrificial agent of 0.25 M Na2S and 0.35 M Na2SO3. This hydrogen generation efficiency is about 23 times higher than that of pure CdS (34.7 μmol g−1 h−1) and 14 times higher than Zn0.64Cd0.36S reference material (56.4 μmol g−1 h−1) prepared by one-pot hydrothermal method. The hierarchical Zn0.64Cd0.36S material exhibits a synergetic effect as a photocatalyst to enhance hydrogen generation and the corresponding photocatalytic mechanism is discussed in detail. This work demonstrates a feasible morphology preservation strategy to prepare novel hierarchical composites with specific chemical composition, high surface area, and abundant active sites, characterized by a rapid diffusion and separation of photogenerated charge carriers proving a visible-light driven photocatalytic hydrogen generation.

Dual-emitting hierarchical Bi4(GeO4)3/Zn2GeO4 hybrid microspheres have been prepared by a facile one-pot hydrothermal synthesis of Zn2GeO4 with the addition of pre-synthesized BiOBr nanoplates. The phase composition and morphology evolution of the Bi4(GeO4)3/Zn2GeO4 composites are investigated depending on the amounts of BiOBr precursor used in the hydrothermal process. The photoluminescence peaks at 412 and 532 nm for the as-prepared Bi4(GeO4)3/Zn2GeO4 are ascribed to Bi3+ emission and defect-related centers in the Zn2GeO4 component, respectively, and the features show a quenching response toward a temperature increase. The fluorescence intensity ratio (FIR) of Bi3+: 3P1–1S0 (412 nm) to the defect emission center of Zn2GeO4 (532 nm) can be exploited as a self-calibrated temperature index for potential thermometer applications. The maximum relative sensitivity (Sr) is 3.96% °C−1 in the temperature range of 20 °C to 100 °C. This work expands the rational design strategy for controllable particle morphology and structure modulation, and further explores their synergetic distinctive properties and potential optical sensor applications.

The adequate potassium resource on the earth has driven the researchers to explore new-concept potassium-ion batteries (KIBs) with high energy density. Graphite is a common anode for KIBs; however, the main challenge faced by KIBs is that K ions have the larger size than Li and Na ions, hindering the intercalation of K ions into electrodes and thus leading to poor rate performance, low capacity, and cycle stability during the potassiation and depotassiation process. Herein, an amorphous ordered mesoporous carbon (OMC) is reported as a new anode material for high-performance KIBs. Unlike the well-crystallized graphite, in which the K ions are squeezed into the restricted interlayer spacing, it is found that the amorphous OMC possesses larger interlayer spacing in short range and fewer carbon atoms in one carbon-layers cluster, making it more flexible to the deformation of carbon layers. The larger interlayer spacing and the unique layered structure in short range can intercalate more K ions into the carbon layer, accommodate the increase of the interlayer spacing, and tolerate the volume expansion, resulting in a battery behavior with high capacity, high rate capability, and long cycle life.