•BiOCl micro-assembles consisting of ultrafine nanoplates.•Excellent oxygen reduction properties.•Novel catalyst for air electrode of aluminum air batteries.•The electro-catalytic activity is closely related to the density of oxygen vacancy on the surface of the BiOCl samples.•A higher ratio of the {001} facets in BiOCl crystals is favorable for the enhancement of the electrocatalytic activity.BiOCl micro-assembles appearing spherical and plate-like in shape consisting of ultrafine nanoplates were successfully synthesized by a simple hydrothermal method. The obtained BiOCl micro-assembles were characterized as oxygen reduction reaction (ORR) catalyst for air electrode of aluminum air batteries by using linear polarization and constant-current discharge techniques. The effect of precursor concentration on the electrochemical properties of the air electrodes based on the synthesized BiOCl micro-assembles was intensively investigated. The results demonstrated that the BiOCl catalyst exhibited promising ORR performance. Koutecky–Levich analysis indicated that a two-electron reaction was favored for the ORR mechanism of the BiOCl (0.18) sample.

ZnO:La3+,Li+ nanoparticles were successfully prepared by co-precipitation, citric acid-assisted co-precipitation, co-precipitation combined solid-state reaction and thermal decomposition method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and luminescence spectrophotometry were employed to characterize the crystal phases, particle sizes and luminescence properties of the as-prepared nanopowders. The results indicate that all the prepared samples crystallize in a hexagonal wurtzite structure. The ZnO:La3+,Li+ prepared by citric acid-assisted co-precipitation method has a particle size of about 80 nm, which is the smallest among all the samples. Fluorescence (FL) spectra of all samples exhibit three typical emissions: a violet one centered at around 400 nm, blue around 450 nm and 466 nm, and weak green near 520 nm. But the samples prepared by co-precipitation method show a strong and wide green light emission located at about 500 nm. The ZnO:La3+,Li+ nanoparticles synthesized by the co-precipitation method demonstrate relatively the strongest emission intensity.

A series of Li+ and Eu3+ co-doped double tungstate NaLa(WO4)2 (NLW) red phosphors have been successfully synthesized by an ion exchange method under a hydrothermal condition. The effects of Li+ doping concentration on the crystal structure, morphology and photoluminescence properties were investigated using the XRD, TEM and photoluminescence (PL) measurements. The results reveal that the samples have phase-pure scheelite structure and adopt spherical particle morphology. Furthermore, room temperature PL spectrum shows that the optical brightness is highly dependent on the concentration of doping Li+, which is determined by ion exchange duration and the precursor concentration of LiNO3. As 5% Li+ ions was introduced into the crystal lattice, the emission intensity was enhanced by more than 10-fold as compared with the pristine one. Moreover, the co-doping of Li+ can substantially improve the effective excitation of the NaLa(WO4)2:Eu3+ phosphors under near-UV region.Highlights► A simple hydrothermal-assisted ion exchange method to synthesize Li+ and Eu3+ co-doped NaLa(WO4)2. ► Considerable photoluminescence enhancement due to the Li+ doping. ► Potential application as red nanophosphors in near-UV type LEDs

Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template. The effects of amount of template, pH value of solution and hydrothermal temperature on mesostructure of samples were systematically investigated. The final products were characterized by XRD, TEM, FT-IR, and BET. The results indicate that all the cerium-zirconium mixed oxides present a meso-structure. At molar ratio of n(CTAB)/n((Ce)+(Zr))=0.15, pH value of 9, and hydrothermal temperature of 120 °C, the samples obtained possess a specific surface area of 207.9 m2/g with pore diameter of 3.70 nm and pore volume of 0.19 cm3/g.

Sn-doped In2O3 (ITO) nanopowders were prepared in ethanol solvent by solvothermal process. The effects of the solvothermal temperature, coprecipitation pH value and SnO2 content on the products phase and microwave absorption were investigated by X-ray diffractometry and microwave reflectance. ITO nanopowders with cubic structure can be respectively prepared at 250 and 270°C for 6 h. The prepared product is InOOH or the mixture of InOOH and In3Sn4O12 when the solvothermal temperature is below 250°C. With rising solvothermal temperature and prolonging time, the absorption of the ITO powders gradually decreases. The products are ITO nanopowders by coprecipitating at pH=9 or 11, but ITO powders with Sn3O4 at pH=6. The absorption of powders prepared at pH=6 is better than that at any other pH value. The products are all ITO nanopowders and crystal size reduces with increasing SnO2 content. The microwave absorption of ITO nanopowders with SnO2 content of 8% (mass fraction) is the best among samples with different SnO2 contents.

Sn-doped In2O3 (ITO) nanopowders in square shape were prepared in ethylene solvent by a solvothermal process, using In (4N) and SnCl45H2O as starting materials. The effects of solvothermal temperature and coprecipitation pH on the products were investigated using XRD, XPS, and TEM. Mixtures of InOOH crystals and In4Sn3O12 crystals were prepared at 210°C or 230°C and ITO nanopowders with cubic structure were obtained at 250°C or above 250°C. When the coprecipitation pH was 6, the product was ITO with impurity Sn3O4. When the pH was 9, the product was single phase ITO.