•Flower-like ZnO/α-Fe2O3 NSs were prepared via a two-step synthesis method.•The samples exhibits the flower-like microstructure assembled with sheets.•Flower-like ZnO/α-Fe2O3 NSs exhibit good gas sensing performance.This paper reports a facile two-step synthesis route for the preparation of flower-like ZnO/α-Fe2O3 nanosheets (NSs). The resulting nanocomposites consist of many irregular sheets with average thickness of 0.30 μm which closely packed at one end. And the surfaces of sheets appear smooth on the side and rough on the other side. The formation of unique structure can be attributed to corrosion of aqueous alkali to ZnO inner core. The gas-sensing testing results show that the ZnO/α-Fe2O3 composites exhibit excellent gas-sensing properties to ethanol vapor at low optimum work temperature of 240 °C, such as the great response and recovery capacity, high response, and good linearity in the gas concentration range of 50–400 ppm, suggesting its potential applications in detecting ethanol at low concentrations.

•Flower-like CuO/ZnO NRs were prepared via a two-step synthesis method.•The samples exhibits the flower-like microstructure assembled with rods.•Flower-like CuO-decorated ZnO NRs exhibit great gas sensing performance.Flower-like CuO/ZnO hierarchical structures were prepared via a flexible two-step synthesis method, in which nanorods-assembled flower-like ZnO microstructures with the diameter about 430–1680 nm and the length about 3.6–8.8 μm were prepared in advance through a chemical solution method, and then a frost-like layer of CuO nanoparticles (NPs) decorated on the surface of ZnO nanorods (NRs) via an ionic-layer adsorption and reaction method. Compared with pure ZnO NRs, the flower-like CuO-decorated ZnO NRs show an obvious improvement in gas sensing performance. The gas sensing mechanism of the CuO-decorated ZnO NRs was discussed in relation to the catalytic effect of CuO and the introduction of the p-n junction between CuO and ZnO.

•The composite thin film electrodes (CTFEs) were prepared with nanotubes and nanoparticles.•The CTFEs possess the rapid electron transport and high surface area.•The CTFEs exhibit lower recombination rate and longer electron life time.•The CTFEs have great applied potential in the field of photovoltaic devices.The composite thin film electrodes were prepared with one-dimensional (1D) TiO2-B nanotubes (NTs) and zero-dimensional TiO2 nanoparticles (NPs) based on different weight ratios. The electron transport properties of the NTs/NPs composite thin film electrodes applied for dye-sensitized solar cells had been investigated systematically. The results indicated that although the amount of dye adsorption decreased slightly, the devices with the NTs/NPs composite thin film electrodes could obtain higher open-circuit voltage and overall conversion efficiency compared to devices with pure TiO2 NPs electrodes by rational tuning the weight ratio of TiO2-B NTs and TiO2 NPs. When the weight ratio of TiO2-B NTs in the NTs/NPs composite thin film electrodes increased, the density of states and recombination rate decreased. The 1D structure of TiO2-B NTs can provide direct paths for electron transport, resulting in higher electron lifetime, electron diffusion coefficient and electron diffusion length. The composite thin film electrodes possess the merits of the rapid electron transport of TiO2-B NTs and the high surface area of TiO2 NPs, which has great applied potential in the field of photovoltaic devices.

•The composited film was constructed by TiO2 nanocrystals and nanorods.•The TiO2 nanorods in composited film electrodes provide a direct electron transport path.•DSCs based on the composited film electrodes have much lower Kr, longer τn and Ln.The TiO2 thin film (CTTF) composed of nanocrystals (NCs) and one-dimensional (1D) single crystalline nanorods (NRs) was prepared and then used as electrode to fabricate dye sensitized solar cells (DSCs). The kinetic parameters of electron transport in CTTF were investigated. Results indicated that due to the direct path for fast electron transport in NRs, the fabricated CTTF electrodes-based DSCs have much lower recombination rate, longer electron life time and electron diffusion length than that based on the pure TiO2 NCs electrodes.

Anatase titania (TiO2) nanocrystals with an average size of 12 nm were synthesized by combining sol–gel method and hydrothermal crystallization technology. Mesoporous TiO2 thin film electrodes (MTTFEs) were prepared by variations in layer of screen-printed TiO2 nanocrystals pastes, and dye-sensitized solar cells (DSCs) based on different thickness of MTTFEs were fabricated with dye C106. Under the irradiation of 100 mW cm−2 air mass 1.5 global (AM1.5G) sunlight, the short-circuit photocurrent density (Jsc) and overall conversion efficiency (η) was improved when the thickness of MTTFEs increased from 2.1 μm to 9.8 μm, and obvious decreases of the Jsc and η were found when the film thickness was further increased over 9.8 μm. The kinetic parameters of electron transport were investigated by the transient photoelectrical and electrical impedance measurements, and then the influence of MTTFEs thickness on electron transport performance in DSCs were further discussed. The results showed that the density of states (DOS) and recombination rate (Kr) increased with the MTTFEs thickness increasing. Furthermore, when the thickness of MTTFEs was in the range of 2.1–9.8 μm, the electron lifetime (τn), the electron diffusion coefficient (Dn), and the electron diffusion length (Ln) of devices increased, but these parameters decreased gradually with the further increased thickness of MTTFEs, which influenced the electronic transport performance of DSCs.

The hollow spheres of anatase TiO2 with higher photocatalytic activity have been fabricated by spherical CaCO3 nanoparticles as a template, and titanium sulfate (Ti(SO4)2) as a precursor, and the CaCO3 templates were dissolved subsequently in dilute HNO3 solution. The TiO2 hollow spheres samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and N2 adsorption–desorption isotherms. The characterization results indicate that as prepared TiO2 hollow spheres sample was transformed to anatase phase in calcined at 400 °C, and the anatase TiO2 hollow spheres have a higher specific surface area and show much better photocatalytic activity than commercial P25 in the photodegradation of Rhodamine B under the UV irradiation.

Nickel nanoparticles coated with zinc sulphide can form complex spherical with a core–shell structure. This coating process was based on mercaptoacetic acid (HSCH2COOH) as a primer to render the nickel surface vitreophilic, thus it renders nickel surface compatible with ZnS. The morphology, structure, chemical composition, optical properties and magnetic properties of the product were investigated by using various techniques, including transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), photoluminescence (PL) spectroscope and vibrating sample magnetometer (VSM). It was found that the Ni/ZnS nanocomposites exhibited both magnetic and photoluminescent properties.