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We report a new facile route to synthesize the ZnO nanotubes by thermal annealing of solid nanorods in ambient NH3. The unique characteristic of this approach allows achievement of ultrathin nanotubes with well-organized hexagonal nanowalls and sealed layouts. On the basis of our experimental observations, we developed a nanotube formation mechanism illustrating the following: (i) energetically active nanorod surfaces could be readily passivated to form a few-atoms-thick Zn3N2layer and (ii) nanopores generated from the seed layer were extended to the inside of nanorod bottoms and then propagated upward until they reached the tops of the nanorods. On the basis of key features of these tubular structures, we assessed the electrochemical performance of the nanotubes as anode materials in lithium ion batteries, demonstrating significant improvements in cycling performance over counterparts made of solid nanostructures.

The TiO2/mica pearlescent pigments were prepared by the hydrolysis of TiOCl2 on the natural mica (muscovite) followed by a calcinations process. The phase transformation of anatase to rutile during calcination and their proportion in the TiO2 thin layer have been analyzed by XRD measurements. The pH controlling during the initial stage of hydrolysis of TiOCl2 showed a pronounced effect on the phase transformation of TiO2 on the substrate. This result may be due to the fact that the pH controlling during the hydrolysis affects the crystal structure and size of TiO2. The decrease in crystallinity and crystallite size of TiO2 resulted in lowering the temperature of phase transformation from anatase to rutile.