We show an effective experimental method to prepare hierarchically porous zinc oxide (ZnO) spherical nanoparticles through a self-assembly pathway using surface-modified colloidal ZnO nanocrystallites as the building blocks and P-123 copolymers as the template in aqueous solution. Copolymers are thoroughly removed by Soxhlet extraction with ethanol and calcination at 400 °C. The final products have been characterized by X-ray powder diffraction (XRD) pattern, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and photoluminescence (PL) spectroscopy. On the basis of calorimetric measurements reported separately, the surface enthalpy (γ) of the hydrated porous ZnO is 1.42 ( 0.21 J/m 2 , in good agreement with that of ZnO nanoparticles. The calorimetric results support the presence of self-assembled ZnO nanocrystallites in the nanoporous ZnO. Photocatalytic activitiy of porous ZnO nanoparticles has been tested on the photodegradation of phenol under ambient condition, indicating that porous ZnO nanoparticles show superior activity to TiO 2 nanoparticles (PC-500).

TiO is a promising and safe anode material for lithium ion batteries (LIBs). However, its practical application has been plagued by its poor rate capability and cycling properties. Herein, we successfully demonstrate a novel structured TiO anode with excellent rate capability and ultralong cycle life. The TiO material reported here shows a walnut-like porous core/shell structure with hybridized anatase/amorphous phases. The effective synergy of the unique walnut-like porous core/shell structure, the phase hybridization with nanoscale coherent heterointerfaces, and the presence of minor carbon species endows the TiO material with superior lithium storage properties in terms of high capacity (∼177 mA h g at 1 C, 1 C = 170 mA g), good rate capability (62 mA h g at 100 C), and excellent cycling stability (∼83 mA h g was retained over 10 000 cycles at 10 C with a capacity decay of 0.002% per cycle).

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