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Tetragonal-phase BaTiO3 powders of particle size 370 nm were synthesized by microwave sintering at 850 °C. The raw materials were BaCO3, TiO2, and alanine. SiC microspheres were used as microwave conductors. The effects of the holding time, sintering aids, and SiC addition on the preparation of BaTiO3 were investigated. The results indicate that the addition of SiC as a microwave acceptor leads to formation of microwave micro-regions. This enables uniform heating of the raw materials and decreases the calcination temperature needed to obtain BaTiO3. Alanine coordinates with Ba, and this loosens the metal–CO3 bond and promotes separation of CO2, decreases the BaCO3 decomposition temperature, and provides a higher nucleation site density. It gives an idea about the microwave solid-state synthesis of BaTiO3 powder. [ABSTRACT FROM AUTHOR]

Honeycomb nitrogen-doped porous carbon (NPC) was prepared for supercapacitor applications by hydrothermal carbonization and KOH activation process. This process used glucose as the carbon source and trans-1, 2-cyclohexane diamine tetraacetic acid as the nitrogen source. It can both control the morphology and improve the electrical performances of the as-achieved NPC. The porous carbon electrode offers improved electrochemical properties with a capacitance as high as 423 F/g at 0.5 A/g. There was excellent cycling stability with 92.5% capacitance retention after 5000 cycles at 10 A/g current density as well as good rate performance with 300 F/g even at 20 A/g. This is due to the hierarchical porous structure, high specific surface area, numerous nitrogen groups, and good electrical conductivity. Moreover, the symmetric supercapacitor based on the porous carbon materials in neat DLC301 electrolyte delivers a high energy density of 58.75 Wh/kg and an excellent power density of 250 W/kg. Two assembled supercapacitors were connected and utilized for the driving recorder to work normally for 15 s. These satisfactory electrochemical properties indicate that the honeycomb 3D porous carbon has good prospects as an electrode for supercapacitors. [ABSTRACT FROM AUTHOR]