We report a new type of core-shell heterostructure consisting of a rod-like NiCo2S4 (NCS) core and an urchin-like Ni(1-x)Co x (OH)2 (NCOH) shell via a simple hydrothermal route coupled with a facile electrodeposition. NCS nanorod arrays (NRAs) can not only act as excellent electrochemically active materials by themselves, but they can also serve as hierarchical porous scaffolds capable of fast electron conduction and ion diffusion for loading a large amount of additional active materials. Moreover, it is observed that the urchin-like NCOH nanosheets coating could bind the inner NCS nanorods together and thereby reinforce the whole structure mechanically. Meanwhile, more effective pathways for electrons are available in the NCS@NCOH hybrids than an individual NCS nanorod. Benefiting from both structural and compositional features, the NCS@NCOH electrode exhibits greatly improved electrochemical performance with high capacity (3.54 C cm(-2) at 1 mA cm(-2)) and excellent cycling stability (78% capacity retention after 4000 cycles). Moreover, a battery-type device is also fabricated by using NCS@NCOH as a positive electrode and activated carbon (AC) as a negative electrode, displaying high capacity (2.51 C cm(-2) at 2 mA cm(-2)) and good durability (88.8% capacity retention after 4000 cycles) as well.

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Layered and rod‐like K3Ti5NbO14 was synthesized via the solid‐state chemistry, and it was exfoliated into nanosheets through a novel mechanical cleavage technology. X‐ray diffraction was utilized to determine the phase changes of all the specimen during the total process, and the microstructure of the samples was analyzed by scanning electron microscope and transmission electron microscope. The formation mechanism was also discussed in detail, the results indicated that the compression and shearing should play a main function in the crack and the cleavage of the aggregated layered compound. UV–vis absorption spectroscopy was used to monitor the consecutive buildup of the (PEI/Ti5NbO14)n film. The resulting quasi‐linear increase at the top absorbance as a function of the sequential assembly number for the multilayer film indicated that the nanosheet had deposited uniformly in each dipping cycle. The photocatalytic activity of K3Ti5NbO14‐related products was examined. Compared with original layered compound, nanosheet precipitate had good property under irradiation of ultraviolet light.

TiO2/Multi-walled carbon nanotubes (MWNTs) were prepared via a wet chemical route with hydrolysis of titanium salts. The purification and oxidation treatment of MWNTs in concentrated HNO3 solution were conducted to modify the nanotubes. Then the pre-treated carbon nanotubes were added into the titanium salt and in the end the composites were formed. The microstructure of as-prepared TiO2/MWNTs composite was studied by TEM. The samples were calcined at different temperature. By X-ray diffraction (XRD), the phase transformation of nano-structured TiO2 in composites was determined. The photocatalytic activity of samples being calcined at different temperature was studied by using the conversion of methyl orange in aqueous solutions as probe reaction. The influence of the structure on photocatalysis efficiency was discussed. By contrast with that of pure TiO2 nanoparticles, the special structure of TiO2/MWNT composite could remarkably improve the efficiency of the photocatalytic reaction. The results indicated that the excited e- in conduction band of TiO2 might transfer into MWNTs and the possibility of the recombination of e-/h+ pairs decreased.

In order to reduce the silicon content to the maximum allowed value for the production of high-purity titanium dioxide, a hydrometallurgical process on the desiliconization during alkaline leaching of titanium slag under atmospheric pressure was studied. The effect of leaching temperature, initial NaOH concentration, leaching time and mass ratio of alkali to slag, on the efficiency of silicon removal were investigated. The results show that when the mass concentration of NaOH is 30%, mass ratio of alkali to slag 3:1, the leaching temperature 120°C and the retention time about 120min, the content of silicon in solid is reduced to 0.45%. Simultaneously, the content of aluminum is reduced to 1.62%, without affecting the content of titanium. The kinetics on the desiliconization during alkaline leaching of titanium slag was carried out. The results show that under the leaching parameters mentioned above, the apparent activation energy is calculated to be 45.43kJ/mol.