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[Display omitted] • MoS 2 /TiO 2 /Ti 3 C 2 T x composites with Ti-S-Mo covalent bond were synthesized. • Doping Ni element could regulate electronic structure of MoS 2 /TiO 2 /Ti 3 C 2 T x. • Ni-MoS 2 /TiO 2 /Ti 3 C 2 T x composites have an enhanced EMA performance. Two-dimensional MXene and its composites are among the most attractive electromagnetic wave absorption (EMA) materials due to their unique structure. While previous studies have investigated 2D/2D MoS 2 /Ti 3 C 2 T x heterojunctions for EMA, there is still a need for further adjustments to interface structure to enhance polarized electron density and electron transfer capacity. In this study, Cl-Ti 3 C 2 T x was prepared by Lewis acid molten salt etching of Ti 3 AlC 2 , and S-Ti 3 C 2 T x was prepared by replacing Cl with S. MoS 2 nanosheets were grown on the surface of S-Ti 3 C 2 T x by a simple hydrothermal method, forming a Ti-S-Mo covalent interface. The EMA properties of the composites were further optimized by adjusting the interface oriented polarization and electronic structure through Ni doping. Compared to MoS 2 /TiO 2 /Ti 3 C 2 T x , the electromagnetic wave absorption performance of Ni-MoS 2 /TiO 2 /Ti 3 C 2 T x had been significantly improved. When the Ni doping amount was 0.086 mmol, the minimum reflection loss of Ni-MoS 2 /TiO 2 /Ti 3 C 2 T x could reach −48.04 dB at 8.64 GHz, with an effective absorption bandwidth of 3.28 GHz. This study provides theoretical basis and experimental evidence for the follow-up research of MXene-based composite EMA materials. [ABSTRACT FROM AUTHOR]

Abstract: Nearly monodisperse nanoparticles were synthesized by an environmentally benign low-temperature (140–180°C) method involving pressure-induced decomposition of metal oleates in alcohol. XRD and TEM were employed in the characterization of the samples. In this study, Fe3O4, CoO, MnO, CoFe2O4, MnFe2O4, and a mixture of Ni, NiO, Ni2O3 nanoparticles, exhibiting various shapes and assemblies, were obtained. [Copyright &y& Elsevier]

Abstract: The synthesis of nanoparticles via the decomposition of organometallic compounds has been studied extensively, but the effect of pressure has received little attention. Here we firstly focus on the pressure effect, and utilize it as well as the solvent and temperature effects to develop a “green” cheap low-temperature (140–200°C) strategy via the decomposition of iron oleate in alcohol (or other alkanols) using oleic acid as the protecting reagent. The obtained monodisperse Fe3O4 nanocrystals (NCs) exhibit satisfying superparamagnetism. The mechanism of the process has been investigated and it was shown both high pressure and alkanol as the solvent can facilitate the formation of magnetite NCs. Furthermore, the solvent used in the preparation can control the shape, size and dispersion of NCs. In addition, the effects of reactant concentration, reaction time, temperature, and the mol ratio of oleic acid on the Fe3O4 NCs have also been discussed. [Copyright &y& Elsevier]