Mesoporous TiO 2 has gained increasing interest because of its outstanding properties and promising applications in a wide range of fields. In this Perspective, we summarize the significant advances on the synthesis of mesoporous TiO 2 in terms of rationally controlling the hydrolysis and condensation rates of titanium precursors to enable the cooperative assembly and/or successful infiltration via the templating methods. The rational designs and fundamentals for preparing mesoporous TiO 2 are presented in the context of improving the conversion efficiencies of solar energy (e.g., maximizing the UV and/or visible light adsorption, minimizing the recombination of photogenerated electron−hole pairs, and optimizing the mass and charge transport) and enhancing the performances of lithium-ion batteries. New trends and ongoing challenges in this field are also highlighted and proposed.

A homologous Ni–Co based nanowire system, consisting of both nickel cobalt oxide and nickel cobalt sulfide nanowires, is developed for efficient, complementary water splitting. The spinel‐type nickel cobalt oxide (NiCo2O4) nanowires are hydrothermally synthesized and can serve as an excellent oxygen evolution reaction catalyst. Subsequent sulfurization of the NiCo2O4 nanowires leads to the formation of pyrite‐type nickel cobalt sulfide (Ni0.33Co0.67S2) nanowires. Due to the 1D nanowire morphology and enhanced charge transport capability, the Ni0.33Co0.67S2 nanowires function as an efficient, stable, and robust nonnoble metal electrocatalyst for hydrogen evolution reaction (HER), substantially exceeding CoS2 or NiS2 nanostructures synthesized under similar methods. The Ni0.33Co0.67S2 nanowires exhibit low onset potential of −65, −39, and −50 mV versus reversible hydrogen electrode, Tafel slopes of 44, 68, and 118 mV dec−1 at acidic, neutral, and basic conditions, respectively, and excellent stability, comparable to the best reported non‐noble metal‐based HER catalysts. Furthermore, the homologous Ni0.33Co0.67S2 nanowires and NiCo2O4 nanowires are assembled into an all‐nanowire based water splitting electrolyzer with a current density of 5 mA cm−2 at a voltage as 1.65 V, thus suggesting a unique homologous, earth abundant material system for water splitting.

The rational design and controllable synthesis of strongly coupled inorganic/graphene hybrids represents a long-standing challenge for developing advanced catalysts and energy-storage materials. Here, we report a simple sol-gel method toward creating ultradispersed TiO2 nanoparticles on graphene with an unprecedented degree of control based on the precise separation and manipulation of nanoparticles nucleated, grown, anchored, and crystallized and the reduction of graphene oxide (GO). The hybrid materials show ultradispersed anatase nanoparticles (~5 nm), ultrathin thickness (≤3 layers), and a high surface area of ~229 m(2)/g and exhibit a high specific capacity of ~94 mA h g(-1) at ~59 C, which is twice as that of mechanically mixed composites (~41 mA h g(-1)), demonstrating the potential of strongly synergistic coupling effects for advanced functional systems.

A magnesiothermic reduction approach is designed to synthesize mesoporous Si/C nanocomposites with ultrasmall, uniform silicon nanoparticles (ca. 3 nm) embedded in a rigid mesoporous carbon framework. The resultant mesoporous Si/C nanocomposites present excellent performance with high reversible capacity, good Coulombic efficiency and rate capability, and outstanding cycling stability in lithium-ion battery applications.

A sandwich-like 2D-mesoporous-carbon/MoS -nanosheet heterostructure is fabricated for the first time. The hybrid structure is composed of three well-stacked monolayers: an ordered-mesoporous-carbon monolayer, a MoS monolayer, and a further ordered-mesoporous-carbon monolayer. This unique heterostructure exhibits excellent electrochemical performance as an anode material for lithium-ion batteries.