The flowerlike ZnO nanostructures, which consisted of swordlike ZnO nanorods, have been prepared by a cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal process at low temperature (120 °C). The XRD pattern indicated that the flowerlike ZnO nanostructures were hexagonal. Furthermore, the SAED and HRTEM revealed that the swordlike ZnO nanorods were single crystal in nature and preferentially grew up along [001]. Finally, the mechanism for the CTAB-assisted hydrothermal synthesis of flowerlike ZnO nanostructures has been preliminarily explained by polar crystal growth theory and surfactant action theory.

A thin Fe2TiO5 layer was produced on hematite either by evaporating a TiCl4 solution on FeOOH or by a simple HF-assisted Ti treatment of FeOOH, both followed by annealing. The prepared Fe2TiO5-hematite heterostructure showed a significant enhancement in photocurrent density compared to that of the pristine hematite. For example, the sample after HF-assisted Ti treatment exhibited a significantly enhanced photocurrent of 2.0 mA/cm(2) at 1.23 V vs RHE. Moreover, the performance of the Fe2TiO5-hematite heterostructure can be further improved by coupling with Co-Pi catalysts, achieving a higher photocurrent of 2.6 mA/cm(2) at 1.23 V vs RHE. Synchrotron-based soft X-ray absorption spectroscopy analyses clearly revealed the existence of an Fe2TiO5 structure on hematite forming a heterojunction, which reduced the photogenerated hole accumulation and then improved the performance.

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This work presents the synthesis of 1D aligned Pt–Ni nanostructures with ultrahigh aspect ratio (>1000) based on the anodic aluminum oxide (AAO) template and their composition- and aspect-ratio-dependent catalytic performances to methanol oxidation reaction (MOR). The 1D aligned Pt–Ni nanostructures were electrochemically deposited in the pores of the AAO template, and the diameter and length of the synthesized nanostructures are comparable with the diameter of pores and thickness of the used AAO. The aspect ratio of the 1D aligned nanostructures can be tuned merely by altering AAO templates with the appropriate aspect ratios. Voltammetric results show that the catalytic activities (both mass activities and specific activities) of the 1D aligned Pt–Ni nanostructures for MOR are composition dependent, and the highest electrocatalytic activity exhibits at a Pt/Ni molar ratio of 1:1 (PtNi). The mechanism of the promoting effect of Ni on Pt is explained based on modification of the electronic characteristics of the surface Pt atoms (Pt 4f) by Ni atoms due to the shift in electron transfer from Ni to Pt. Moreover, the catalytic activities of the 1D aligned PtNi nanostructures are in an aspect-ratio-dependent manner and increase in the order 0D PtNi nanoparticles, 1D aligned PtNi nanostructures at aspect ratios of ∼200, 500, and 1300 due to the preferential exposure of certain crystal facets and less surface defects of the 1D aligned nanostructures. This work is believed to open new and exciting possibilities for enhancing the performance of fuel cell catalysts. Our synthesized high-aspect-ratio 1D aligned nanostructures may also be useful as sensors and in other electrochemical applications.