As anode materials for lithium ion batteries, two three dimensionally ordered macroporous TiO 2 , one with disordered inter-particle mesopores formed by the aggregation of nanoparticles (3DOM) and another with inner-particle mesopores generated by a surfactant templating strategy (3DOMM), have been synthesized using poly(styrene-methyl methacrylate-3-sulfopropyl methacrylate potassium) (P(St-MMA-SPMAP)) spheres as a hard template and their electrochemical properties are compared. SEM and TEM observations reveal that both 3DOM TiO 2 and 3DOMM TiO 2 have well-ordered macropores and interconnected macropore walls with a regular periodicity. 3DOMM TiO 2 demonstrates a specific surface area of 139 m 2 g À1 , which is higher than that of 3DOM TiO 2 (99 m 2 g À1 ) due to the smaller crystallite size and inner-particle mesopores. The electrolyte adsorption results show that both 3DOM TiO 2 and 3DOMM TiO 2 have similar adsorption capacities despite a difference in the surface area. Electrochemical impendence spectroscopy analysis shows that 3DOMM TiO 2 has a lower charge transfer resistance and faster Li + diffusion coefficient than 3DOM TiO 2 . Moreover, both 3DOM TiO 2 and 3DOMM TiO 2 possess excellent initial capacity of 248 mA h g À1 and 235 mA h g À1 at 0.2 C and 208 mA h g À1 and 202 mA h g À1 at 1 C, respectively. The reversibility study demonstrates that the 3DOMM TiO 2 displays higher cycling capacity, superior rate behavior and higher Coulombic efficiency because the higher surface area provides more active sites and the presence of the inner-particle mesopores in the walls of macropores serve as a bicontinuous transport path and affords a shorter path length for diffusion of Li ions compared with the 3DOM TiO 2 and its crystallite aggregated mesopores. The reversible capacity of 106 mA h g À1 observed for the 3DOMM TiO 2 can be retained after 200 charge-discharge cycles at a relatively high current rate of 4 C. This cycle stability performance can be equally attributed to the crystallite size and inner-particle mesopores in the 3DOMM TiO 2 . Moreover, the existence of a bicontinuous porous structure in the 3DOMM TiO 2 can further enhance the lithium insertion/extraction capacity at high rates. We believe that this study can shed light on the 3DOMM structure as a promising material for highly enhanced performance in lithium ion batteries.

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We demonstrate an alkali modification process to produce highly dispersed ultrafine Pt nanoclusters with metallic Pt 0 and oxidized Pt 2+ species as co-catalyst anchored on nanosheet-constructed yolk-shell TiO 2 (NYTiO 2-Pt) acting as light harvesting reactor for highly efficient photocatalytic H 2 production. Benefiting from the high surface area, highly dispersed ultrafine Pt nanoclusters (~0.6 nm) with Pt 0 and Pt 2+ species and special nanosheet-constructed yolk-shell structure, this novel light harvesting reactor exhibits excellent performance for photocatalytic H 2 production. The NYTiO 2-Pt-0.5 (0.188 wt% Pt) demonstrates an unprecedentedly high H 2 evolution rate of 20.88 mmol h-1 g-1 with excellent photocatalytic stability, which is 87 times than that of NYTiO 2-Pt-3.0 (0.24 mmol h-1 g-1 , 1.88 wt% Pt), and also much higher than those of other TiO 2 nanostructures with the same Pt content. Such H 2 evolution rate is the highest reported for photocatalytic H 2 production with such a low Pt content under simulated solar light. Our strategy here suggests that via alkali modifying the photocatalysts, we can not only enhance the H 2 production for solar energy conversion but also significantly decrease the noble metal content for cost saving.

Unique walnut-shaped porous MnO2/carbon nanospheres via in situ carbonization of amorphous MnO2 nanospheres demonstrate enhanced reaction kinetics for lithium storage.

Hierarchically structured porous TiO2-B spheres have been synthesized via a hydrothermal process using amorphous titania/oleylamine composites as a self-sacrificing template. The TiO2-B spheres are constructed by interconnected nanotubes and possess a high specific surface area of 295 m2 g-1. When evaluated as an anode material in lithium-half cells, the as-obtained TiO2-B material exhibits high and reversible lithium storage capacity of 270 mA h g-1 at 1 C (340 mA g-1), excellent rate capability of 221 mA h g-1 at 10 C, and long cycle life with over 70% capacity retention after 1000 cycles at 10 C. The superior electrochemical performance of TiO2-B material strongly correlates to the synergetic superiorities with a combination of TiO2-B polymorph, hierarchically porous structure, interconnected nanotubes and spherical morphology. Post-mortem structural analyses reveal some discrete cubic LiTiO2 nanodots formed on the outer surfaces of TiO2-B nanotubes, which might account for the slight capacity loss upon prolonged electrochemical cycling.