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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.

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.

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.

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.

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.

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.

Process design and techno-economic evaluation of glucose isomerization on Sn-Beta require reliable catalytic reaction rate expressions and kinetic constants. Here, the isomerization of sugars (glucose, fructose and mannose) in water using Sn-Beta is investigated at various temperatures ranging from 70 to 130 °C. It is shown that the catalyst deactivates during the course of the reaction. A phenomenological model that describes the isomerization reaction in the presence of deactivation is developed and the corresponding kinetic constants are estimated from experimental data.

The consequences of meso-/microporous zeolite structures on distribution and activity of active sites (Bronsted acid and metal sites) in molybdenum (Mo) impregnated lamellar MFI and lamellar MWW zeolites were investigated in direct methane aromatization (DMA) reactions. In comparison with their microporous analogies (Mo/MFI and Mo/MWW), the mesopores in the Mo/lamellar MFI and Mo/lamellar MWW zeolites facilitated the dispersion of Mo in zeolite micro-channels. The catalytic DMA reactions showed that the Mo loaded lamellar MFI and lamellar MWW zeolites enabled efficient methane conversion, aromatic product formation, and coke accumulation in the initial stage of reaction, while their performances were similar to those of Mo/MFI and Mo/MWW catalysts in the long term run. A plausible explanation to this scenario is that active sites in Mo/lamellar MFI and Mo/lamellar MWW can be accessed by reactants through both micropores and mesopores. The facilitated transport and accessibility to active sites by mesopores accounted for initial fast reaction and deactivation rates of Mo loaded lamellar zeolites. After mesopores were clogged by deposited coke in DMA reactions, micropores of zeolites were responsible for the long term catalyst performances, which were similar to Mo loaded microporous zeolites.

Three dimensionally ordered mesoporous-imprinted (3DOm-i) zeolites with well-controlled mesoporosity and Si/Al ratio were synthesized within the confined space of three dimensionally ordered mesoporous (3DOm) carbon by conventional hydrothermal synthesis method. It was found that the incipient wetness technique used to prepare the 3DOm carbon can significantly affect the mesoporous structure of the resulting carbon template. 3DOm carbon with a nearly complete replication from silica colloidal crystals can be used to control the mesoporosity of 3DOm-i zeolites. Confined synthesis of hierarchical zeolites under conventional hydrothermal synthesis conditions offers a large variety of synthesis recipes for controlling the framework, morphology and composition of 3DOm-i zeolites. It shows that a dilute initial synthesis solution favors the formation of single crystalline 3DOm-i silicalite-1, while a higher starting silica concentration results in polycrystalline 3DOm-i silicalite-1. The polycrystalline feature might benefit the disassembly of the resulting 3DOm-i zeolites for the preparation of highly monodisperse zeolite nanocrystals. 3DOm-i ZSM-5 with tunable acid site concentrations was also achieved by varying Si/Al ratios in initial synthesis solutions. The catalytic performance of 3DOm-i ZSM-5 was tested with the self-etherification of benzyl alcohol, a reaction severely limited by the mass transport of reactants and products in the micropores of ZSM-5 catalysts. It was revealed that for this reaction 3DOm-i structure can significantly improve the reaction rate by alleviating diffusion limitation, and the Si/Al ratio of 3DOm-i ZSM-5 also plays an important role in the effective utilization of the zeolite catalysts.

To reduce the incidence of peri-implant infections, zeolite coatings on titanium alloy surface have been prepared and their antibacterial as well as anti-adhesive properties were studied. Continuous zeolite A thin films of 1–4 μm thickness were coated onto titanium alloy surface through in situ crystallization method under hydrothermal conditions. Small amount of silver ions (ca. 2 wt.%) was incorporated into the zeolite layer by an ion-exchange process to provide antibacterial activity. X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), contact angle measurement and scratch test were employed to characterize the coating surfaces. The antibacterial activity of silver incorporated zeolite coatings against methicillin-resistant Staphylococcus aureus (MRSA) evaluated in vitro showed that bacterial proliferation was significantly inhibited both in the culture medium surrounding the material and on the material surface. Moreover, the superhydrophilic nature of zeolite coating provides additional anti-adhesive property to the material surface. The results of in vitro cytotoxic assessment showed that both the zeolite coatings and silver-containing zeolite coatings have good biocompatibility. The antibacterial and anti-adhesive zeolite coatings will have potential application in orthopedic implants.

A benign and facile process for forming monodisperse, hollow porous silica shells of a novel cubic morphology is identified. Templated on monodisperse crystalline germania cores that can be removed via aqueous dissolution, the hollow shells and their core–shell precursors are amenable to assembly into highly porous, gap-free near-monolayer films through manual and evaporative assembly techniques.