AbstractSmart surface coatings of silicon (Si) nanoparticles are shown to be good examples for dramatically improving the cyclability of lithium-ion batteries. Most coating materials, however, face significant challenges, including a low initial Coulombic efficiency, tedious processing, and safety assessment. In this study, a facile sol–gel strategy is demonstrated to synthesize commercial Si nanoparticles encapsulated by amorphous titanium oxide (TiO2), with core–shell structures, which show greatly superior electrochemical performance and high-safety lithium storage. The amorphous TiO2 shell (≈3 nm) shows elastic behavior during lithium discharging and charging processes, maintaining high structural integrity. Interestingly, it is found that the amorphous TiO2 shells offer superior buffering properties compared to crystalline TiO2 layers for unprecedented cycling stability. Moreover, accelerating rate calorimetry testing reveals that the TiO2-encapsulated Si nanoparticles are safer than conventional carbon-coated Si-based anodes.

•Monodisperse ordered mesoporous TiO2 microspheres with large mesopores, high surface areas and highly crystallized framework were synthesized through a novel confinement synthesis method.•The morphology of the mesoporous TiO2 materials can be well tuned from solid mesoporous microspheres to hemi-microspheres and even to hollow mesoporous microspheres.•High photoconversion efficiencies up to 8.5% have been achieved by using the obtained mesoporous titania microspheres.Uniform discrete mesoporous titania microspheres have been synthesized via a facile and controllable interface-directed co-assembly approach by using 3-dimensional macroporous carbon (3DOMC) as the nanoreactor for the confined co-assembly of template molecules and titania source. By adjusting the synthesis parameters, hollow mesoporous microspheres and hemi-microspheres can also be synthesized. The obtained mesoporous TiO2 microspheres possess a large pore size (4.7 nm), high accessible surface area (145 m2/g), large pore volume (0.26 cm3/g) and highly crystallized anatase pore walls. The dye-sensitized solar cell based on the mesoporous TiO2 microspheres exhibits high photoconversion efficiencies up to 8.5%, which are largely attributed to their intrinsic high surface area, high porosity and well-connected crystalline framework.Monodisperse mesoporous TiO2 microspheres: uniform discrete mesoporous titania microspheres with high surface area and high crystalline framework have been synthesized via a facile and controllable interface-directed coassembly (IDCA) approach for dye sensitized solar cells with a high photoconversion efficiency of 8.5%.

In this study, a 3-dimensional interconnected hierarchical ordered macro/mesoporous titania (HOPT) with thin walls, crystalline framework, large cavities (∼420 nm), uniform mesopores (3.7 nm) and high surface area (177 m2 g−1) was synthesized through a facile bi-template interface-directed deposition method using poly(propylene oxide)-block-poly(ethylene oxide)-block-poly(propylene oxide) (Pluronic P123) triblock polymer as a soft template and structure directing agent, titanium isopropoxide (TIPO) as a titania source and 3-dimensional ordered macroporous carbon (3DOMC) as the hard template and the nanoreactor. This was followed with a two-step thermal treatment in nitrogen and air. Under simulated sunlight irradiation at room temperature, the HOPT shows an ultrahigh photocatalytic activity for the degradation of Rhodamine B (RhB) with a fast reaction rate that is three times higher than commercial titania nanoparticles (P25).