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The interface characteristics of electrode materials are of tremendous value for supercapacitors, however, poor conductivity, instability in harsh reaction conditions and limited ion mobility in oxide materials are identified as immense challenges for generating high energy density without renouncing the power capability. Herein, a peculiar catalytic chemical vapour deposition (CCVD) approach is employed to decorate a very thin carbon capsules (CCs) on the surface of LiMn2O4 nanorods to synthesize a very active and uniformly distributed LiMn2O4/CCs nano-hybrid material with modified interface characteristics. The CCs not only provide the physicochemical protection as well as improve the electrical conductivity. As an electrode material, LiMn2O4/CCs possess the specific discharge capacitance of 451 F/g which is far superior to LiMn2O4 (304 F/g) at the current density of 0.5 A/g in 0.5 M Li2SO4 aqueous solution. In addition, the LiMn2O4/CCs exhibit an outstanding specific capacitance of 380 F/g even at a much higher current density of 8 A/g. Moreover, after 3000 charge and discharge cycles, LiMn2O4/CCs electrode retains nearly 95% of initial capacity, higher than that of spinel LiMn2O4 electrode which retains only 93%. This innovative technique can be adopted to construct a large variety of other nano-hybrid materials for consumer utilization in the field of supercapacitors.

The inevitable corrosion of magnetic microwave absorber (MA) remains a great challenge to adapt oxygen-containing environment. Herein we developed a plasma-induced approach for protecting the magnetic MA by anchoring robust SiO2 layers on their surface. Keeping the original flaky shape of FeSiAl (FSA) led to breaking the Snoek limit, which brought excellent ultra-low-frequency absorption. In detail, the ultrathin amorphous silica layer (5 nm) grew on FSA surface by the facile Stober method at low cost firstly. Plasma technology was introduced to make these SiO2 layers dense and attain the integrated P-FSA@SiO2. SiO2 layer protected FSA from the corrosive medium, which increased polarization resistance to 186.9 kΩ·cm2 of P-FSA@SiO2 (from 97.46 kΩ·cm2 of pure FSA) and decreased the corrosion current to 18.45 μA/cm2 (from 63.35 μA/cm2). The corrosion of the samples in acid solution also verified the electrochemical characterizations. Meanwhile, rich interface and sheet ordered structure enable P-FSA@SiO2 exhibit enhanced microwave absorption in ultra-low-frequency through multiple reflections, magnetic loss and the interface polarization between core and shell. The minimum reflection loss of P-FSA@SiO2 reduced from −8.0 dB (FSA) to −12.4 dB and the efficient absorption band (

Superior thermal quenching and degradation of phosphors are required for long lifetime lighting devices, such as light-emitting diodes, which can be realized through composition modification. Here, Al-N bonds in AlON: Eu 2+ phosphors are substituted by higher bond order of Si-C. Photoluminescence (PL) results show thermal quenching (at 150 °C) and thermal degradation (after 600 °C treatment in air) are improved by 5% and 8% with a small decrease of PL intensity in 5% SiC doped AlON: Eu 2+ phosphor. To explain these observations, first-principles computational study was performed to understand the Si and C configuration in AlON:Eu 2+ . The calculations reveal that Si and C elements are not randomly distributed in AlON lattice. It was found that Si prefers occupying tetrahedral sites (Td-Si) and the insertion of C in Td-Si is always energetically favorable, which results in the formation of SiC 4 and SiNC 3 clusters. Thus, the Al-N substitution by Si-C induces a stronger local structure, which accounts for the emission redshift and better thermal stability.

As a novel alternative biodegradable metal, magnesium possesses great potential and feasibility for bone fracture fixation due to its suitable mechanical properties, high degradability and biocompatibility. However, poor corrosion resistance in physiological fluids restricts their practical applications. In this study, HA contained coating on AZ31 Mg alloy substrate is prepared by MAO technique under various treatment times. The effect of treatment time on microstructure, composition, mechanical and corrosion properties is systematically investigated. The results indicate that MAO treatment is an effective route to improve the corrosion resistance. The enhanced corrosion is attributed to the barrier effect of the coatings. The failure mechanism of the MAO samples in Hank's solution is studied by long time immersion. A model for corrosion mechanism and corrosion process of the MAO coating on AZ31 Mg alloy in Hank's solution is proposed.

Generally speaking, thermal stability is the key factor for microwave absorbers (MAs) at high temperature. In this paper, we first propose to apply a novel material called Cr2AlC (CAC) in the high temperature field. The self-made high purity CAC powder prepared by salt bath exhibits good microwave absorption performance and outstanding. Thermogravimetric (TG) analysis indicates the CAC begins to oxidize significantly above 800 °C. Moreover, the effective medium theory is adopted to calculate the microwave absorption performance for the CAC/paraffin composite material. We found that the sample with 70 wt% CAC (CAC70) has a minimum reflection loss of −25.09 dB at 11.08 GHz and its effective absorption bandwidth (below −10 dB) is 2.2 GHz (10.2–12.4 GHz) at the thickness of 2.00 mm, which indicates a thin layer of Al2O3 at room temperature will not affect the entry of electromagnetic waves and internal electrical losses. The high anti-oxidation layered structure CAC provides an opportunity to expand microwave absorption in high temperature applications.

As a promising material for electromagnetic microwave absorption, FeSiAl (FSA) alloy always suffers from inadequate corrosion resistance in the marine environment. Herein, the Raman and X-ray photoelectron spectroscopy (XPS) depth profiling techniques are adopted to investigate the basic corrosion behavior of FSA in salt spray environment. The Raman analysis contributes to the understanding of the composition change at various corrosive periods while the XPS depth profiling reveals the corrosion process of Fe0→Fe2+→Fe3+ in a sequence. The observed corrosion rates (CRs) of FSA immersed in 5 wt% NaCl solution for 1, 24 and 48 h are 2.99 × 10−12, 4.90 × 10−12 and 5.85 × 10−12 m/s, respectively. The increasing value of CRs as a function of time demonstrates the accelerated corrosion tendency. Moreover, to suppress the corrosive behavior of FSA alloy, carbon is decorated on its surface by catalytic chemical vapor deposition method using acetylene as the carbon source. The carbon coating restrains the corrosion process by impermeability and hydrophobicity of carbon materials in corrosive mediums. This study will help in the designing of microwave absorbers which can resist corrosion in harsh reaction conditions as well as available at commercial level to save the economy.

Designing of materials which can resist aging and corrosion in harsh reaction conditions is required to mitigate the omnipresent issue of electromagnetic interference pollution. Particularly, FeSiAl alloy is a relevant composite material, however, it always suffers aging and corrosion when exposed to crude saline environment. Herein, Carbon-encapsulated FeSiAl (FeSiAl@C) hybrid flakes are developed by catalytic chemical vapor deposition (CCVD) technique through the reaction of FeSiAl precursor with acetylene (C2H2) gas at 300 °C for 5 min. The carbon coating efficiently improves the impedance matching characteristics of FeSiAl powder leading to enhance microwave absorption. Not only that, the carbon capsule also plays an effective shielding function to prevent the alloy from corroding. Specifically, the FeSiAl@C-300 °C delivers increased complex permeability and permittivity in the frequency range of 7–14 GHz, as well as improved impedance matching. In addition, the corrosion resistance is measured using linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in 5 wt% NaCl solution. The results indicate that the synthesized hybrid exhibits excellent corrosion resistance capability. So, the composite synthesis is a worthy approach to design hybrid materials for effective microwave absorption and corrosion resistance properties for practical applications.