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MXenes, as a two-dimensional transition metal carbide or nitride based electrode material with excellent performance, shows excellent performance similar to graphene, which is considered as an ideal electrode material for supercapacitors. However, the application of two-dimensional lamellar Ti3C2Tx is limited by its low theoretical specific capacity and easy agglomeration between layers. Herein, through a simple hydrothermal synthesis strategy, we introduced three-dimensional (3D) Ni (OH)2–MnO2 nanoflowers between layered Ti3C2Tx sheets to form a unique 3D hierarchical pillared structure, which not only solves the problem of easy agglomeration between Ti3C2Tx layers, but also gives play to the advantage of Ni(OH)2 and MnO2 as the high specific capacitance of metal compounds, and this composite obtained shows the synergistic effect between components. In addition, due to its three-dimensional structure, Ni(OH)2–MnO2 nanoflowers can effectively hinder the accumulation of Ti3C2Tx nanosheets, thereby increasing their active electrochemical degree points and promoting the transport of electrolytes. Furthermore, the three-dimensional pillared Ni(OH)2–MnO2@Ti3C2Tx composite we prepared displays a large specific capacitance of 2523 F g−1 at 2 mV s−1. At the high current density of 10 A g−1, after 10,000 cycles, the electrode material finally maintained 88.1% of the initial specific capacitance, which proved its remarkable cycle stability. Moreover, the energy density and power density of the symmetrical supercapacitor (SSC) made of this composite materials are 36.3 Wh kg−1 and 421.5 W kg−1, respectively. All above results indicate that the easy preparation method, low cost, Ni(OH)2–MnO2@Ti3C2Tx composites with excellent performance will be suitable for different application scenarios of multifunctional and digital supercapacitors. [ABSTRACT FROM AUTHOR]

Thermoelectric materials convert thermal energy into electricity directly. Constructing nanostructured composite architectures can be an effective strategy to develop thermoelectric performance. SnSe/Ti3C2 composite materials were synthesized through the electrostatic self-assembly method followed by spark plasma sintering. The interfaces introduced by Ti3C2 can scatter carriers effectively, thus increasing the Seebeck coefficients (S), finally, a high absolute S value of ~ 296.2 µV K−1 was obtained at 773 K. At the same time, the high-density interfaces of SnSe/Ti3C2 composites enhance the phonon scattering, a low lattice thermal conductivity klat of 0.54 W m−1 K−1 was obtained. Benefit from the elevated Seebeck coefficient and decreased thermal conductivity, a ZT of 0.1 was obtained at 773 K along the pressing direction, compared with the pure SnSe, the thermoelectric performance improved by 68%. This research will provide a new way for the development of the thermoelectric properties of polycrystalline SnSe. [ABSTRACT FROM AUTHOR]

A new type of TiO2 nanowires/two-dimensional MXene composite (TiO2 nw/Ti3C2) was synthesized by oxidation of Ti3C2 MXene in potassium hydroxide (KOH) solution at low temperature. Using this approach, numerous TiO2 nanowires with the length of 20–100 nm uniformly grow on the Ti3C2 sheets surface, which increase the surface areas and prevent the restacking of Ti3C2 sheets. Electrochemical testing results revealed that the as-prepared TiO2 nw/Ti3C2 nanocomposite can drastically improve the reversible capacity compared with pure Ti3C2. Remarkably, TiO2 nw/Ti3C2 nanocomposite shows high initial capacity of 768.7 mAh g−1 at 100 mA g−1 and the capacity can remain about 216.4 mAh g−1 after 200 cycles, which is more than twice as much as that of Ti3C2 (98.3 mAh g−1). [ABSTRACT FROM AUTHOR]

ZnO-based linear resistance ceramics were synthesized from ZnO-MgO-NiO-AlO-SiO-SmO at 1320 °C for 3 h by the conventional ceramics method. The microstructure and electrical properties of the linear resistance ceramics have been systematically investigated in detail. The experimental result indicates that appropriate amounts of SmO addition can obviously improve the resistance temperature coefficient of ZnO-based linear resistance ceramics compared with the SmO-free samples. The samples with the SmO content of 0.5 mol% exhibit excellent electrical properties with the resistivity of 209.8 Ω cm and the resistance temperature coefficient of 2.38 × 10/°C, which is improved by 46 and 92 %, respectively. Moreover, the nonlinear coefficient of voltage decreases to 1.15, decreased by 4.30 % and the relative density reaches to 96.43 %, increased by 4.91 %. [ABSTRACT FROM AUTHOR]

A low loss high-frequency magnetic composite with Ni0.8Zn0.2Fe2O4 (NZO) ultrafine particles embedded in a high density polyethylene (HDPE) matrix was fabricated by using a simple low-temperature hot-pressing technique. The magnetic and dielectric properties of the as-prepared composites were investigated in details. The results indicate that as the volume of the ceramic fillers increase, the permittivity, permeability, dielectric and magnetic loss of the composite all increase. The cut-off frequencies of the composites are all above 1 GHz. Because of the low resistivity of NZO, the dielectric losses of the composites are big and decrease with frequency below 100 MHz. Good frequency stabilities of the permittivities and permeabilities, and low dielectric and magnetic losses within the measurement range have been observed. For the composite containing 30 vol% NZO, the permittivity, dielectric loss, permeability and magnetic loss are 3.7, 0.0025, 2.2 and 0.002 at 100 MHz, respectively. [ABSTRACT FROM AUTHOR]

Well-dispersed lithium niobate powders with an ideal stoichiometry were rapidly prepared at 650 °C by a molten salt method, with Li2CO3 and Nb2O5 as raw materials. The dwelling time was 5 min. Li2SO4–Na2SO4 was used as flux in the present work, which can lead to stoichiometric lithium niobate powders due to its very fast chemical reactions during the whole process. IR spectral characteristics strongly support the stoichiometric composition of our present powder samples. [ABSTRACT FROM AUTHOR]