Three-dimensional (3D) yttrium iodate (YIO3) hollow microspheres consisting of nanotube arrays are synthesized via a one-step hydrothermal process without any surfactants. In the hollow microspheres approximately 5 μm thick and 15–45 μm in diameter, the nanotubes in the arrays radiate outward from the center to the edges and are approximately 5 μm long and 100–200 nm in diameter. The formation of the 3D hollow microspheres can be easily controlled by changing the experimental conditions. The growth mechanisms of the 3D hollow microspheres are discussed in detail, and their optical properties are investigated.Three-dimensional (3D) yttrium iodate (YIO3) hollow microspheres consisting of nanotube arrays are synthesized via a one-step hydrothermal process without any surfactants.Highlights► The 3D YIO3 hollow microspheres have been prepared successfully. ► The 3D YIO3 hollow microspheres consist of nanotube arrays. ► The growth mechanisms of the nanostructures are also surveyed.

We herein report a direct growth of novel three-dimensional (3D) Mg3P2 dendritic microstructure by the direct reaction between metal Mg and red phosphorus (P4). The 3D pine-like Mg3P2 dendritic microstructures comprise many dendrites with sharp tips, the lengths and the widths are tens of micrometers and hundreds of nanometers. The morphologies of Mg3P2 can also be tuned by adjusting the reaction temperature. The shapes of Mg3P2 vary from cross, grass to dendrite with increasing reaction temperature. A growth mechanism of Mg3P2 microstructures with tunable shapes was proposed and explained in detail.Highlights► Novel 3D Mg3P2 dendritic microstructures have been prepared successfully. ► Mg3P2 with various structures can be obtained by changed reaction temperature. ► A growth mechanism of Mg3P2 microstructures with tunable shapes was explained.

Porous and trigonal TiO2 nanoflakes (p-TiO2) have been synthesized via a simple hydrothermal calcination process, and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV–vis absorption/reflection spectroscopy (UV–vis). The X-ray diffraction patterns of the as-prepared samples show that p-TiO2 has an anatase structure. Transmission electron microscopy images indicate that p-TiO2 consists of sheet-like particles with numerous pores about 100 nm in diameter. Ultraviolet–visible reflection spectroscopy exhibits that the absorption edge acquires a blue shift with increased calcination temperature. The effects of the calcination temperature, catalyst dosage, and initial rhodamine B (RhB) concentration on the sonocatalytic activity for removing RhB are investigated in detail. The results show that the as-prepared p-TiO2 obtained at the optimal calcination temperature of 600 °C exhibits a higher sonocatalytic activity than commercial P25. Based on the effects of the initial RhB concentration on sonocatalytic activity, the sonocatalytic degradation kinetics of RhB is also investigated.Highlights► Porous TiO2 nanoflakes have been synthesized by a simple process. ► The porous TiO2 nanoflakes possess relatively better sonocatalytic activity. ► RhB degradation on porous TiO2 can be described by Langmuir–Hinshelwood model.

Magnesium phosphide (Mg3P2) microstructures having microwire shapes with ultrahigh-aspect-ratio and three-dimensional (3D) urchin, flower, and branched shapes (myriapod or leaf) are synthesized using a one-step reaction without any catalysts or templates. The microstructures with different shapes are easily controlled through various temperatures. With increasing reaction temperature, the morphology of Mg3P2 microstructures changes from microwires with ultrahigh-aspect-ratio to branched shapes similar to myriapods or leaves. The growth mechanisms of these microstructures are discussed in detail.Magnesium phosphide microstructures having microwire shapes with ultrahigh-aspect-ratio and three-dimensional (3D) urchin, flower, and branched shapes (myriopod or leaf) are synthesized using a one-step gas–solid reaction method without any catalysts or templates.Highlights► The novel Mg3P2 microstructure has been prepared successfully by a simple method. ► The microwires with tunable shapes have also been prepared. ► The growth mechanisms of these microstructures are also surveyed.

Hexagonal, bullet-like ZnO microstructures and nanorod arrays have been prepared successfully by a simple hydrothermal method without surfactants. The structure and composition of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrum (EDS), infrared spectrum (IR), and UV–vis diffusive reflectance spectrum (UV–vis). The as-synthesized bullet-like ZnO has hexagonal microstructures with an average diameter of about 10 μm and a length of 30 μm. The obtained ZnO nanorod arrays are highly oriented. Their average diameter is around 50–100 nm, and their length is about 1 μm. In the present work, the effect of concentration, heating temperature, and time on the morphology of ZnO structures was studied experimentally, and their formation was discussed in detail. The photocatalytic degradation of methylene blue (MB) was also investigated.

The reaction of alcohols and carboxylic acids catalyzed by acids is the traditional method used to prepare esters in the chemical industry. In this study, we report the synthesis of active graphitic carbon nitride (g-C3N4) that may be used in the one-step reaction between benzaldehyde and alcohol to promote the selective formation of esters under visible light irradiation. Compared with the reaction carried out without illumination, g-C3N4 showed obvious improvements in ester formation. The presence of tin dioxide can also contribute to the formation of esters under visible light irradiation. The use of g-C3N4 for the esterification of various alcohols was explored, and the catalyst showed promising results.