Metal oxide-based materials with yolk-shell morphology have been intensively investigated as important anodes for Li-ion batteries due to their large ion storage ability, high safety, and excellent cycling stability. In this work, in situ carbon-coated yolk-shell V2O3 microspheres were synthesized via a template-free polyol solvothermal method. The growth of yolk-shell microspheres underwent coordination and polymerization, followed by an inside-out Ostwald-ripening process and further calcination in N2 atmosphere. The thin amorphous carbon layers coating on the microspheres' surface came from polyol frameworks which could protect V2O3 during the charge-discharge process and led to a better stability in Li-ion batteries. The in situ carbon-coated yolk-shell V2O3 microspheres showed a capacity of 437.5 mAh·g(-1) after 100 cycles at a current density of 0.1 A·g(-1), which was 92.6% of its initial capability (472.5 mAh·g(-1)). They were regarded as excellent electrode materials for lithium-ion batteries and exhibit good electrochemistry performance and stability.

Mixed-phase MgTiO3/MgTi2O5 microspheres were prepared through a salicylic acid precursor method and further calcined in air. The microspheres were formed through coordination, polymerization, and aggregation processes. Salicylic acid acted as a ligand in coordinating with metal ions, in addition to acting as a structure-directing agent in the polymerization and aggregation of the titanate precursor microspheres via chemical bonds and electrostatic attraction. The mixed-phase MgTiO3/MgTi2O5 microspheres prepared by this method showed excellent photocatalytic hydrogen production efficiencies that were two and four times higher than mixed-phase nanoparticles and pure-phase nanoparticles, respectively, owing to their closed phase junctions and sphere-like morphologies. This versatile and facile salicylic acid precursor method was also used to prepare a number of other bivalent metal-based titanate microspheres, including BaTiO3, ZnTiO3, CoTiO3, NiTiO3, and CdTiO3.

CdTiO3 nanorods with different length were prepared from titanium glycolate nanorod template, combined with wet impregnation method and further calcination. The samples were characteried by scanning electron microscope (SEM), transmission electron microscope (TEM), wide-angle X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), thermogravimetric analyser (TG) and ultravioletvisible spectrometer(UV-Vis). The prepared CdTiO3 nanorods are uniform with high crystallinity and high purity, and are about 50, 20, 10 mu m in length, respectively. After loaded 1% (mass fraction) platinum as co-catalyst, their photocatalytic properties for H-2 production were studied. Compared with CdTiO3 nanoparticles, the CdTiO3 nanorods show higher photocatalytic activity. The H-2 producton performance for the longest nanorods is up to 52.9 mu mol/h.

A phase-mixed MgTiO3-MgTi2O5 heterogeneous nanorod is fabricated via an ethylene glycol-mediated route to promote the photocatalytic hydrogen production activity significantly. The excellent charge separation and fast electron transport are the main reasons for the high efficiency due to the formation of phase-mixed heterogeneous junctions.

Herein, with the purpose of improving the efficiency of p-type dye-sensitized solar cells (DSSCs), a new layered photocathode (LP) is fabricated from irregular overlapping wrinkled porous NiO nanosheets. The LP was sensitized by using a commonly used dye, coumarin 343(C343), and then assembled into p-type DSSCs through coupling with a platinum photoanode. Photoelectochemical characterization showed that the LP cell exhibited a clearly enhanced power-conversion efficiency (by a factor of 4) compared with a cell with a NiO-nanoparticle photocathode (NP). This excellent performance could be attributed to the overlapping layered structure, which favored hole transport, as confirmed by electrochemical impedance spectroscopy, and to the large surface area of the porous NiO nanosheets, which were favorable for dye adsorption.

The narrow-narrow band gap semiconductor consisting of heterogeneous CdS nanoparticles/NiTiO3 nanorods was fabricated by firstly synthesizing NiTiO3 nanorods via an ethylene glycol-mediated route and then growing CdS nanoparticles on their surface through a chemical bath deposition method. The CdS nanoparticles and NiTiO3 nanorods were in good contact and formed a heterogeneous composite as seen from SEM and TEM images. The heterogeneous CdS nanoparticles/NiTiO3 nanorods possessed enhanced visible-light-driven photocatalytic activity in the photocatalytic reduction of highly toxic hexavalent chromium, compared to CdS nanoparticles and NiTiO3 nanorods. The excellent photocatalytic performance was attributed to the large electric potential difference between the conduction bands of CdS and NiTiO3, which was favorable for the photogenerated electron transport from CdS to NiTiO3 and efficient photogenerated charge separation at the heterogeneous interface. Moreover, the heterogeneous composites were very stable because the photocatalytic activity remained nearly constant after five cycles, which was favorable for practical applications.