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Morphology evolution of inorganic/organic crystals during crystallization is a universal growth phenomenon. In this work, we have developed a capping agent-assisted strategy to clearly identify the whole process of morphology evolution in solution growth system. One kind of morphology evolution trend with three types of morphologies of cuprous oxide (Cu₂O) was kinetically observed at varying the molar ratio of EDTA/Cu(II) under three different pH values. Two kinds of morphology evolution trends of zinc oxide (ZnO) were also kinetically observed in the presence of H₂O₂ and CH₃COOH (HAc), respectively. Simulation results show that the morphology evolution of nano- to micro-scale crystals is strongly dependent on the bonding characteristics of a growth system. The present strategy positively explores the interesting principles of morphology evolution of functional materials, and can be widely extended to nano- to micro-scale devices research.

A combination of the remarkably simple technique of electrospinning, developed to fabricate polymer nanofibers, and sol–gel processing has been utilized to produce fine zinc oxide nanofibers with an average diameter of 70 nm. A non-toxic precursor solution of polyvinyl alcohol and zinc acetate was electrospun and the resulting fibers were then calcined at a relatively low temperature to produce ZnO nanofibers. Simultaneous thermal analyses were used to study the formation of ZnO nanofibers from the precursor material. X-ray diffraction was employed to analyze the phases and different microscopy techniques, such as scanning electron microscopy, transmission electron microscopy and atomic force microscopy were used to study the morphology and size of the fibers. Fourier transform infrared spectroscopy was employed to investigate the composition of the precursor and ZnO fibers. The specific surface area of the electrospun nanofibers was determined using the Brunauer–Emmett–Teller method and optical properties were measured by UV-Vis and PL spectroscopy. The very high specific surface area of the ZnO fibers makes them potential candidates for nanodevice applications in gas sensing, dye-sensitized solar cells, and UV/blue emission devices.

Zinc oxide film has been fabricated by converting flower-like structure of zinc carbonate hydroxide made by chemical bath deposition technique. Flower-like structure is employed as charge transport network of dye-sensitized photoanode. Analysis of current density–voltage characteristic shows deposition temperature and deposition time of chemical bath deposition influence photovoltaic performance. Analysis of electrochemical impedance spectroscopy reveals short electron lifetime and high effective electron diffusion coefficient of zinc oxide-based dye-sensitized solar cell.

The degraded performance of annealed ZnO-based photodetector can be improved by embedding an Ag interlayer. The Ag interlay converted to Ag₂O during ZnO deposition. After Ag₂O nanoparticles formed, the interface between ZnO and Ag₂O produced band-bending to redistribute charges and increase the Schottky barrier between the electrical contact and ZnO. The excess Ag interlayer created lattice defects, causing the dark current to increase slightly. The increasing visible PL intensity of annealed ZnO, with the increasing Ag interlayer, clarified the transfer of the photo-generated electron.

A facile and green method was utilized to synthesize core-shelled Zn/ZnO microspheres by boiling Zn microparticles in water for improving the photocatalytic activity of ZnO. The synthesized Zn/ZnO core-shells were investigated by means of scanning electron microscope, X-ray diffractometer and photoluminescence spectrometer, respectively. The morphology analysis showed that the metallic Zn core was about 6 μm in diameter while the ZnO shell was about 600 nm in thickness. Compared to ZnO nanoparticles, the core-shelled Zn/ZnO microspheres exhibited improved photocatalytic activity in degrading methyl orange in water. Our results suggest that the metal–semiconductor junction formed at the Zn/ZnO interface is responsible for the enhanced photocatalytic activity of ZnO.

F, C-codoped ZnO nanoparticles were synthesized by the precipitation method. X-ray photoelectron spectroscopy spectra (XPS) measurements confirmed the existence of F–Zn, C–F, –CF₂– and O–C–O bonds in the lattices of ZnO nanoparticles. The band gap of ZnO was narrowed due to F and C dopants, which should be beneficial for the improvement of the photocatalytic activity. However, our experiments demonstrated that F, C-codoping restrained the photocatalytic activity of ZnO nanoparticles. To detect the possible microstructural defects, the analysis of electron paramagnetic resonance (EPR) was performed. It was suggested that the positive-charged defects were formed by the substitution of F ions for O lattice sites. defects are deep donors and act as recombination centers for photo-generated electrons and holes, which could result in the decrease of the photocatalytic activity. Although the photocatalytic activity of F, C-codoped ZnO is depressed, the antibacterial activity still keeps a comparable level in comparison with that of pure ZnO. Therefore, this material has a potential application in textiles.

Zinc oxide (ZnO) nanorods (ZNRs) and hierarchical ZnO nanosheet–spheres (ZNSs) were prepared through a simple aqueous chemical growth process and a low-temperature solid-phase method, respectively. The prepared ZNRs and ZNSs were mixed to obtain a composite structure by using a circumference oscillator. After structure and morphology characterizations via X-ray diffraction and scanning electron microscopy, the mixture of ZNRs and ZNSs was used as a photoanode in dye-sensitized solar cells (DSSCs). Photovoltaic performance and optimal mixture ratio were investigated. The results indicated that the photovoltaic properties of DSSCs depended on the microstructures, morphologies and mixture ratios of the electrodes. In addition, the mixture of ZNRs and ZNSs (molar ratio of 1:12) yielded an overall light conversion efficiency of 6.02%, with a fill factor of 65.0%, a short-circuit current of 13.49 mA/cm², and an open-circuit voltage of 0.69 V. These values are higher than those of pure ZNRs or pure ZNSs.

Sn–ZnO nanorod array coatings with a low concentration of tin dioxide (0, 0.5, 1, 5 mol.%) were obtained by hydrothermal method on glass or polycore substrates. The synthesized materials are crystallized in the wurtzite structure, which was confirmed by X-ray diffraction analysis. According to scanning electron microscopy arrays of nanorods have an average length 120–180 nm and a diameter of 57–77 nm. It was established that an increase in the temperature of hydrothermal synthesis (from 95${}^{\circ }$C to 200${}^{\circ }$C) leads to a decrease in particle sizes of pure ZnO. All obtained materials have photocatalytic activity in the visible light range. The best photocatalytic activity — 82% degradation of methylene blue in 3 h of visible light irradiation — was shown for material containing 1 mol.% of tin dioxide. This hydrothermal method opens a new pathway for developing new nanostructured photocatalysts.