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Mn3O4 for supercapacitors was prepared by hydrothermal method at different reaction temperature and certain reaction time. Y doped and composite graphene were realized. The morph-ology, structure and electrochemical properties of the samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical workstation. The standard PDF cards 89-4837 are identical and the single phase Mn3O4 belongs to tetragonal system. The space group is I41/amd (No. 141). The prepared Mn3O4 is rod like particle. The specific capacitance of Y-Mn3O4 and Y-Mn3O4/graphene composites can reach 89 F·g-1 and 267 F·g-1 when Y content is 5%. The cyclic voltammetry curves of Y-Mn3O4/graphene composites are rectangular, indicating that Y doped and graphene loading synergistically improve the electrochemical performance of Mn3O4.

In this work, Fe3O4 nanoparticles (NPs) loaded inside and outside halloysite nanotubes (HNTs) were prepared and developed as the heterogeneous Fenton-like catalysts for the removal of representative organic pollutants. Characterization results indicated that the samples with Fe3O4 NPs loaded outside the HNTs lumen (Fe3O4/HNTs) and inside the HNTs lumen (Fe3O4@HNTs) were successfully prepared. Both samples had typical magnetic hysteresis loops, while Fe3O4@HNTs exhibited higher magnetization intensity. The comparative experiments showed that Fe3O4@HNTs had better Fenton-like catalytic ability than that of Fe3O4/HNTs in the degradation of various organic pollutants. Taking Rhodamine B (RhB) as an example, the adsorption thermodynamics and kinetics of RhB onto Fe3O4/HNTs and Fe3O4@HNTs were also investigated. The comparative results demonstrated that the adsorption ability of Fe3O4/HNTs was better than that of Fe3O4@HNTs. Moreover, the dissolved concentration of Fe2+ and production amount of hydroxyl radical (·OH) in the Fe3O4@HNTs-H2O2 system were significantly higher than those in the Fe3O4/HNTs-H2O2 system. Based on aforementioned comparison, the nano-confinement effect in the Fe3O4@HNTs-H2O2 system was verified. This work provides meaningful guidance for the cheap and convenient design of nanoreactors for Fenton-like applications. [ABSTRACT FROM AUTHOR]

A facile one-pot hydrothermal route was selected for the synthesis of ZnCo2O4 and ZnCo2O4/rGO composite electrode materials. The structure, morphology and electrochemical properties of the as-perpared materials were characterized by XRD, SEM and RST5000 electrochemical workstation. ZnCo2O4 electrode materials with a group of radial structure, folding lamellar structure and the spherical structure were obtained by changing the hydrothermal temperature. Results show that after the addition of graphene, ZnCo2O4 exhibits regular polygonal structure and is attached to graphene sheets. Their synergistic effect can effectively improve the electrochemical performance of electrode materials. When the mass ratio of zinc cobaltate to graphene oxide is 6:1, the specific capacitance of ZnCo2O4/rGO composite material is 205F/g, which is 114% higher than that of pure ZnCo2O4.

Mn3O4 for supercapacitors was prepared by hydrothermal method at different reaction temperature and certain reaction time. Y doped and composite graphene were realized. The morph-ology, structure and electrochemical properties of the samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical workstation. The standard PDF cards 89-4837 are identical and the single phase Mn3O4 belongs to tetragonal system. The space group is I41/amd (No. 141). The prepared Mn3O4 is rod like particle. The specific capacitance of Y-Mn3O4 and Y-Mn3O4/graphene composites can reach 89 F·g-1 and 267 F·g-1 when Y content is 5%. The cyclic voltammetry curves of Y-Mn3O4/graphene composites are rectangular, indicating that Y doped and graphene loading synergistically improve the electrochemical performance of Mn3O4.

The effect of heat treatment on microstructure and mechanical properties of Ti-5553 alloy was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that when the alloy is treated in α+β phase zone, tensile strength decreases with raising solution temperature due to decreasing the content of primary α-phase and increasing the size and volume fraction of β phase. A lot of secondary α-phase precipitates from grain boundary and intragranular with β phase transformation during aging treatment. The size of secondary α-phase has significant influence on tensile strength, secondary α-phase coarsens gradually with the increase of aging temperature, resulting in the decrease of tensile strength. It is suggested that for 1240MPa aerospace fasteners the solution temperature of Ti-5553 should be under Tβ, thus adequate β phase, where a lot of secondary α phase precipitates from, is good for the required high strength. Meanwhile, a certain percentage of primary α-phase is kept for acquiring good ductility and toughness. After solution treatment at 810-820℃ for 1.5h, water quenching plus aging at 510℃ for 10h, Ti-5553 shows a better mechanical property with tensile strength 1500MPa, elongation 14.8% and reduction of cross-section area 38.6%. Lots of dimples can be found in tensile fracture after solution treatment and solution+aging treatment, which demonstrate Ti-5553 with good ductility and toughness.