In this paper, porous zinc oxide (ZnO) nanosheets were successfully prepared by a simple low-temperature hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) tests showed that the synthesized product was ZnO with porous sheet structure. The diameter of porous nanosheets was about 100 nm and the thickness was about 8 nm. As a photocatalyst, the degradation efficiencies of porous ZnO nanosheets for methyl orange (MO), methylene blue (MB) and Rhodamine B (RhB) were 97.5%, 99% and 96.8%, respectively. In addition, the degradation efficiency of ZnO for mixed dyes (Mo, MB and RhB) was satisfactory, reaching 97.7%. The photocatalytic stability of MB was further tested and remained at 99% after 20 cycles. In the experiment, ZnO/FTO (fluorine-doped tin oxide) composites were prepared by using ZnO as the conductive layer. Titanium dioxide (TiO₂) was deposited on the surface of ZnO/FTO by electrodeposition, so as to obtain a TiO₂/ZnO/FTO composite. By studying the electrochromic properties of this composite, it was found that the TiO₂/ZnO/FTO composite shows a large light modulation range (55% at 1000 nm) and excellent cycle stability (96.6% at 200 cycles). The main reason for the excellent electrochromic properties may be the synergistic effect between the porous structure and the polymetallic oxides. This study is helpful to improve the photocatalytic efficiency and cycling stability of metal oxides, improve the transmittance of thin films and provide a new strategy for the preparation of ZnO composite materials with excellent photocatalytic and electrochromic properties.

A novel strategy that utilizes rare earth element doping and structure-directing agents was employed to synthesize oxygen-deficient 0.8% Nd–CoMoO₄@NiMoO₄ nanoflowers. The product has excellent electrochemical and photocatalytic properties.

In this paper, Co₃O₄ nanosheets were prepared by the hydrothermal method. The structure of the material was analyzed by morphological characterization and physical phase analysis, which confirmed the preparation of the product, Co₃O₄, showing a nanosheet structure. By studying the electrochromic properties of the prepared products, the results show that the transmittance modulation range of the Co₃O₄ nanosheet is 75% at 780 nm. The coloring response time and bleaching response time is about 3.8 s and 3.4 s, respectively. Electrochemical tests show that the Co₃O₄ nanosheets have good capacitive properties. Their specific capacitance reaches 1850 F/g when the current density is 1 A/g. When the current density is 5 A/g, the specific capacitance can still maintain 99.6% after 5000 cycles. In addition, Co₃O₄//CNTs devices can provide a maximum energy density of 79.52 Wh/kg (1 A/g) and a maximum power density of 11,000 W/kg (15 A/g), showing good energy storage capacity. The above data results indicate that the prepared Co₃O₄ nanosheets can be used as good candidates for supercapacitors. This paper provides a new idea and method for preparing Co₃O₄ materials.

In this paper, we propose for the first time the synthesis of α-MoO₃ nanorods in a one-step procedure at mild temperatures. By changing the growth parameters, the microstructure and controllable morphology of the resulting products can be customized. The average diameter of the as-prepared nanorods is about 200 nm. The electrochromic and capacitance properties of the synthesized products were studied. The results show that the electrochromic properties of α-MoO₃ nanorods at 550 nm have 67% high transmission contrast, good cycle stability and fast response time. The MoO₃ nanorods also exhibit a stable supercapacitor performance with 98.5% capacitance retention after 10,000 cycles. Although current density varies sequentially, the nanostructure always exhibits a stable capacitor to maintain 100%. These results indicate the as-prepared MoO₃ nanorods may be good candidates for applications in electrochromic devices and supercapacitors.