Journal of Inorganic Materials is supervised by Chinese Academy of Sciences and sponsored by Shanghai Institute of Ceramics and Chinese Academy of Sciences (CAS). Published by The Science Press and launched in 1986, it is a monthly journal with 112 pages per issue. It aims to report phased and final achievements of national key projects and the projects of National Natural Science Foundation of China. Its scope covers creative treaties on new inorganic non-metallic materials, including nano-inorganic materials, functional and structural ceramics, functional crystals, energy materials, biomaterials, solid thin film, special glass and inorganic composite. It aims at briefly reporting on achievement obtained at different stages, summarizing and reviewing on the progress of special areas or subjects of inorganic non-metallic materials, and new processes and new techniques.
The journal is included in CA, SCI, JST, EI, CSCD.
Cr
2AlC is a representative material in MAX phase family due to its combination of metallic and ceramic properties such as high electrical conductivity, high thermal conductivity, resistance to corrosion, good oxidation resistance. To further improve the performance of Cr
2AlC, ZrC as a reinforcement was selected to reinforce Cr
2AlC matrix composites by hot pressing technique. The influence of ZrC content on the mechanical property of ZrC/Cr
2AlC composites was investigated. The results showed that the 10 vol% ZrC/Cr
2AlC composite improved the flexural strength (715 MPa) and Vickers hardness (7 GPa) by 80% and 106%, respectively, as compared with those of the pure Cr
2AlC material. The data from this study indicate that Cr
2AlC MAX possesses broad application potential.
Equal channel angular pressing (ECAP) followed by heat treatment was carried out to prepare Ag/Ti
3AlC
2 composites. The effects of heat treatment on the resistivities and mechanical properties of the Ag/Ti
3AlC
2 composites were investigated. Results show that ECAP effectively densifies the Ag/Ti
3AlC
2 compacts, and the layered Ti
3AlC
2 particles are delaminated and aligned due to the shearing effect during ECAP. Alignment of Ti
3AlC
2 particles resulted in the anisotropy of electrical and mechanical properties of the composites. Perpendicular to the alignment of Ti
3AlC
2 particles displayed high resistivity and compressive strength. Moreover, the resistivity and compressive strength increased with following heat treatment, yielding the maximum at 800 ℃. These increments were attributed to the enhanced interfacial reactions between Ag and Ti
3AlC
2 at high temperatures. The findings in this study indicate that densification and microstructural control of Ag/MAX composites can be achieved simultaneously by ECAP, while the following heat treatment can tailor their properties.
Manganese-based oxides are promising cathode materials for zinc-ion batteries. However, these materials often suffer from rapid capacity fade due to structure collapse during charge–discharge processes. Here, we report that the core-shell structured Mn
3O
4@ZnO nanosheet arrays were synthesized on the carbon cloth, combining microwave–hydrothermal process with atomic layer deposition. With an optimized thickness of ZnO coating layer, the capacity retention of the as-formed Mn
3O
4@ZnO nanosheet arrays exhibits 60.3% over 100 discharge–charge cycles at a current density of 100 mA·g
−1. It is demonstrated that the introduction of ZnO layers is beneficial to maintaining the microstructure and improving the structural stability of the Mn
3O
4 electrode material during the charge–discharge process, benefiting from avoiding direct contact with the electrolyte. The design of the well-defined core-shell structure provides an effective way to develop high-performance manganese-based oxide cathode materials for zinc-ion batteries.
As newly-discovered member of the MAB phases, Cr
4AlB
4, has much potential for high-temperature structural applications due to possible formation of a protective oxide scale. By use of “linear optimization procedure” and theoretical model of “bond stiffness” based on first-principle calculations, the phase stability and mechanical behavior of Cr
4AlB
4 were investigated. No imaginary frequencies in phonon dispersion indicate the intrinsic stability. The lower energy as compared with the set of other competing phases also shows the thermodynamic stability. Based on the quantificationally calculated bond stiffness by use of the model of “bond stiffness”, strong covalent bonding is present between Cr and B atoms as well as between B and B atoms, while the Cr-Al (625 GPa) and B-Al (574 GPa) bonds are relatively weak. It follows that Cr
4AlB
4 can be described as the layered structure of strong covalently bonded Cr-B blocks interleaved by Al atomic planes where the bonding is relatively weak, similar to the well-known MAX phases. This demonstrates the similar damage tolerance and fracture toughness of Cr
4AlB
4 with the MAX phases.
Mo
2Ga
2C, a double-A-layer MAX, is reported to be films or powders. This paper researched the sintering properties of M
2Ga
2C powders to make dense bulk samples by vacuum hot-pressing sintering. It was found that 750 °C was a suitable sintering temperature, while higher temperature (850 °C) resulted in decomposition of Mo
2Ga
2C yielding to main product of Mo
2C. During sintering process at 750 °C, its grain size did not increase obviously with sintering time; meanwhile, the size of pores decreased markedly and the relative density increased significantly with the increasing sintering time. Additionally, the hot-pressed samples had obvious texture. Due to layering, some grains changed their orientations during sintering, of which most of the (00
l) planes in the hot-pressed samples preferred to be perpendicular to the direction of hot-pressing sintering. Almost fully dense Mo
2Ga
2C bulk (relative density: 98.8%) was obtained by hot-pressing sintering at 750 °C for 8 h. This advantage of the method suggests that it can serve as promising preparation for Mo
2Ga
2C, a double-A-layer MAX.
Direct methanol fuel cells have good application prospects due to their advantages of convenient operation, high conversion efficiency, low operating temperature, low pollution, and easy storage and transportation of liquid fuel. However, the existing anode catalysts have shortcomings such as low catalytic activity and poor resistance to CO toxicity which restrict their commercial applications. In this study, a series of PtRu/(Ti
3C
2T
x)
0.5-(MWCNTs)
0.5 anode catalyst materials with different ratios of Pt to Ru were prepared by three-step method. Ti
3C
2T
x was obtained by HF corrosion of Ti
3AlC
2. After the compounding of Ti
3C
2T
x and acidified multi-walled carbon nanotubes (MWCNTs), Pt and Ru particles were supported by a solvothermal method. The synergistic relationship of Ru and Pt atoms was analyzed by XRD, SEM, EDS, TEM, and XPS. The results showed that the Ru atoms were mixed with the Pt atoms to form PtRu bimetallic alloy with a particle size of about 3.6 nm. The electrochemical results showed that the Pt
1Ru
0.5/(Ti
3C
2T
x)
0.5-(MWCNTs)
0.5 catalyst had the best electrochemical performance. Its electrochemical active area (ECSA) was 139.5 m
2/g, and the forward peak current density was 36.4 mA/cm
2.
As a new class of two-dimensional transition metal carbon/nitride, MXenes have been proven to be a kind of pseudocapacitive supercapacitor electrode material with excellent electrochemical property, and hold promise in practical use in the near future. In practical applications, it is required to make the electrode materials into planar porous electrodes for capacitor assembly. Herein, a simultaneous ammonization/carbonization method is proposed for the preparation of MXene planar porous electrode. With filter paper as the planar porous template, MXene was coated on the fibers of the filter paper by means of dipping-drying, followed by heat-treatment in an ammonia atmosphere. Finally, the MXene/carbon planar porous composite electrodes were obtained. Analysis results show that the MXene nanosheets are uniformly coated on the carbonization-derived carbon fibers of the filter paper. When the filter paper is immersed 5 times, the areal capacitance reaches 403 mF/cm
2 at a scan rate of 2 mV/s. After the composite electrode is tested for 2 500 times in a galvanostatic charge–discharge cycle at a current density of 10 mA/cm
2, the capacitance is almost the same as the initial capacitance, showing good rate performance and cyclic stability. The MXene/carbon planar porous composite electrodes prepared by simultaneous ammonia/carbonization exhibit excellent electrochemical performance without using either polymer binders or metal current collectors.
Electromagnetic interference (EMI) shielding films with excellent mechanical properties are highly promising for applications in flexible devices, automotive electronics, and aerospace. Inspired by the excellent mechanical properties of nacre derived from its micro/nanoscale structure, we prepared high-performance MXene/cellulose nanocrystals (CNC) composite films by simple solution blending and followed vacuum-assisted filtration process. The presence of CNC significantly improves the mechanical properties with tensile strength increasing from 18 MPa to 57 MPa and toughness improving from 70 kJ/m
3 to 313 kJ/m
3. Meanwhile, the composite film still exhibits high electrical conductivity (up to 10
4 S/m) and excellent EMI shielding efficiency (over 40 dB) with a small thickness of 8 µm.
Ge nanoparticles were synthesized uniformly on MXene sheets via a one-step chemical solution method. The morphology of Ge/MXene was characterized by SEM and TEM. The formation process and optimized synthesis condition were analyzed carefully. Ge/MXene was used as anode for lithium-ion batteries. Their electrochemical performance, including capacity, rate and cycling stability, were tested and evaluated. Ge/MXene exhibited a greatly improved capacity of 1 200 mAh/g during the first hundred cycles at 0.2
C with a loading of 1 mg/cm
2. A capacity of 450 mAh/g at a higher loading of 2 mg/cm
2 was obtained after 100 cycles. The excellence in electrochemistry was attributed to the high conductivity of MXene and its accommodable interlayer space.
In order to rapidly remove Eu(Ⅲ) from aqueous solution, alkalized two-dimensional titanium carbide, Na-Ti
3C
2T
x, was successfully prepared by treating inorganic two-dimensional transition metal carbide (MXene) with NaOH. The adsorption behavior of Eu(Ⅲ) on Na-Ti
3C
2T
x was systematically investigated by batch experiments. The results showed that the adsorption process was greatly affected by the pH and ionic strength of the solution, and reached equilibrium within 5 min. Based on Langmuir model fitting results, the maximum adsorption capacity of Eu(Ⅲ) on Na-Ti
3C
2T
x was calculated to be 54.05 mg/g at pH 4.0 and 298 K. The thermodynamic results suggested that the adsorption process was a spontaneous and endothermic reaction. The adsorption mechanism was further analyzed by energy dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (XRD) and extended X-ray absorption fine structure spectroscopy (EXAFS). These data revealed that Na
+ ions inside MXene galleries were exchanged by Eu
3+ ions and Eu(Ⅲ) existed dominantly in outer-sphere surface complexation after adsorption under acidic pH conditions, but in inner-sphere surface complexation under near-neutral pH conditions. Due to its cost-effective preparation and excellent adsorption performance, Na-Ti
3C
2T
x may be a promising candidate for the efficient removal of trivalent minor actinides and lanthanides from radioactive wastewater.
