Microstructure control and multiple compounding methods in the synthesis stage can enhance microwave absorption performance of microwave absorbents. In this work, we successfully synthesized binary TiB 2 –SiC (TsBC) powders with hexagonal sheet (TiB 2 ) and particle (SiC) interlocking structures by sol-gel carbothermal reduction method. We investigated the effect of raw material ratio and synthesis temperature on the synthesized powders and evaluated the microwave absorption properties of the synthesized TsBC powders. It was found that the TsBC absorber exhibited excellent microwave adsorption properties with the minimum Reflection Loss ( R L ) reached −21.8 dB at 17.4 GHz corresponding to the thickness of 4 mm. This excellent performance was attributed to the interfacial polarization between TiB 2 –SiC interfaces and the multiple reflections between the sheet-particle interlocking structures.
Catalytic conversion and application of bio-based platform chemicals is of great significance. Itaconic acid, one of the abundant and renewable bio-based platform chemicals, could be hydrogenated to produce methylsuccinic acid, which has important applications in pharmaceutical synthesis. Traditional catalysts can be corroded, leached and deactivated in an acid reaction environment, and the stability of the catalysts is a great challenge. Carbothermal reduction was employed to prepare stable ruthenium-based catalysts, and the results confirmed that CO generated in situ functioned as an efficient reducing species in the carbothermal reduction process. The catalysts were applied for the hydrogenation of itaconic acid, and showed good stability and resistance to acid with no obvious loss of activity and less leaching in recycling tests compared to hydrogen reduced samples which exhibited an apparent decrease of 22% for the conversion of itaconic acid. The carbothermal reduced catalysts could maintain 99% conversion and 99% selectivity for methylsuccinic acid, and maintained good stability and acid-resistance under a higher temperature and longer reaction time.
To realize the high value–added utilization of acid-washed iron red, in this paper, acid-washed iron red is used as raw material. Aiming at the problem of low conductivity of iron-based lithium ion batteries (LIBs) LiFePO 4 /C materials, different metal ions are doped in the iron position, and the microstructure and electrochemical properties of the obtained material are systematically studied. Here, LiFePO 4 /C is synthesized through simple carbothermal reduction method using acid-washed iron red as the iron source. On this basis, La (1%, 2%, 3%) doping modification is carried out. Then doped modification is performed on this basis, preferably 2% La-doped LiFePO 4 /C materials. The XRD patterns show that the diffraction peaks of the samples prepared at all doping amounts can be perfectly matched with the standard card ( PDF # 40–1499), and there is no impurity peak, all of which are pure phases. According to the refined data, it is clear that minor amount of La has successfully replaced the position of Fe and incorporated into the lattice. Electrochemical tests show that LiFe 0.98 La 0.02 PO 4 /C has the highest charge and discharge capacity of 146.5/138.2 mAh·g −1 in the first cycle at 0.5C, and the reversible specific capacity of 136.5 mAh·g −1 remains after 50 cycles. Furthermore, the first-principles calculations more strongly confirm that La doping can significantly improve the defects of low electronic conductivity of LiFePO 4 .