Monodisperse AgCl nanospheres were synthesized by a simply designed method. This study aims to prepare AgCl with superior photocatalytic activity. For comparison, AgCl samples were also prepared by modified and conventional methods. Rhodamine B (RhB) was photodegraded differently by the samples utilizing three methods. RhB was photodegraded by the monodisperse AgCl nanospheres at the highest photodegradation rate, which is approximately 8.6 and 43times higher than those of the conventional AgCl and N-doped TiO2 (N-TiO2). Besides, the underlying reasons accounting for the distinct differences were studied in detail. The results show that the monodisperse AgCl nanospheres with an optimum size will contributes to the outstanding photocatalytic activity.

AgPO3 microspheres were prepared by a simple hydrothermal method. The AgPO3 microspheres were characterized by X-ray powder diffraction (XRD), scanning electronic microscopy (SEM), Brunauer-Emmett-Teller (BET), UV-vis absorption spectroscopy (UV-vis), and photoluminescence (PL) measurement. SEM reveals that the AgPO3 microspheres were constructed by the accumulation of small particles. The as-prepared AgPO3 microspheres sonocatalytically degraded Rhodamine B (RhB) excellently under ultrasonic irradiation. The sonocatalytic ability results from the (OH)-O-center dot radicals induced by AgPO3 microspheres under ultrasonic irradiation. The effects of other conditions on ultrasonic activity were also investigated. The content of (OH)-O-center dot radicals in the reaction system was determined to further verify the above conclusions. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.

g-C3N4/Ag3PO4 heterojunction photocatalyst with visible-light response was prepared by a facile coprecipitation method. The photocatalysts were characterized by X-ray powder diffraction, transmission electron microscopy, UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy. The photocatalytic activities of the obtained samples were tested by using Rhodamine B (RhB) as the degradation target under visible light irradiation. g-C3N4/Ag3PO4 decomposed RhB, more effectively than the pure Ag3PO4 particles did, and 2 wt.% g-C3N4 had the highest activity. Furthermore, 2 wt.% g-C3N4/Ag3PO4 degraded high-concentration RhB more potently than unmodified Ag3PO4 did, probably because g-C3N4/Ag3PO4 heterojunction photocatalyst enhanced the photocatalytic activity by efficiently separating the photogenerated electron-hole pairs. (C) 2014 Published by Elsevier Ltd.

A simple and efficient approach to the preparation of hollow or porous metal phosphide nanoparticles was presented. Bulk and supported Ni2P, CoP, FeP, and Cu3P were successfully synthesized by reducing metal pyrophosphate precursors in flowing hydrogen. The structural properties of these samples are investigated using X-ray powder diffraction, transmission electron microscopy, inductively coupled plasma and X-ray photoemission spectroscopy. The Ni2P/SiO2 catalysts were used for the gas phase catalytic hydrodesulfurization of dibenzothiophene. The hydrodesulfurization activity of the catalyst reached 99% when the reaction temperature was 340°C. In the paper, a possible reaction mechanism was discussed to form Ni2P, CoP, FeP, and Cu3P. The route and mechanism could also be applied to the preparation of other metal phosphides.

The Ag3PO4 and Ag3PO4 sonocatalysts with surface enrichment of Br− anions (Br–Ag3PO4) were synthesized using a facile precipitate process. Various analysis, including X‐ray diffraction, transmission electron microscopy, scanning electron microscope, Brunauer–Emmett–Teller, photoluminescence (PL) spectra, and UV–Vis absorption spectra were carried out to investigate the property and structure. The effect of a variety of changing conditions on ultrasonic degradation of organic dye has been investigated. Both of them exhibited obvious activity for sonocatalytic degradation of organic dyes. However, Br–Ag3PO4 sonocatalysts showed much higher activity than that of Ag3PO4. By XRD analysis, the Br− anions of the surface of Ag3PO4 has been transformed into AgBr in the preparation process. The high activity could be attributed to AgBr for modifying Ag3PO4. By detecting hydroxyl radicals (·OH) in the reactive solution, we found that AgBr on the surface of Ag3PO4 can help to produce a lot of additional ·OH radicals. These ·OH radicals may be significant reason to improve Ag3PO4 activity, which further proved the ·OH radical mechanism of Ag3PO4 degradation of dyes under ultrasonic radiation. In addition, kinetic analysis and sonocatalytic mechanism were discussed in detail.

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.

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 5μm thick and 15–45μm in diameter, the nanotubes in the arrays radiate outward from the center to the edges and are approximately 5μm long and 100–200nm 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.

Perfect, sectorial, and branched Sb2O3 microstructures (st-Sb2O3) were synthesized using a hydrothermal method based on a seeded growth procedure. The structure and composition of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), UV-vis diffusive reflectance spectroscopy (UV-vis), and photoluminescence (PL) spectroscopy. SEM images show that the st-Sb2O3 microstructures consist of several prolate microtubes, and the perimeter of the sectors are around 10-40 mu m. The prolate microtubes are approximately 30 mu m long and 10 mu m wide. The growth of st-Sb2O3 may be controlled by changing the different experimental conditions. The introduction of the seed during the growth process plays an important role in the formation of the microstructures. In addition, the PL spectrum of the st-Sb2O3 microstructures shows a strong fluorescence. The formation mechanism of the st-Sb2O3 microstructures is discussed in detail.

The one-dimensional (1D) frog egg-like Mn(IO3)2/MnO2 nanostructures with ultra-high aspect ratio are prepared by reaction of MnCl2·4H2O with KIO3 using a mild hydrothermal method. Tunable shapes, including several three-dimensional structures (grass-, leaf-, and rose-like), can also be obtained by altering experimental conditions. The X-ray powder diffraction (XRD) and energy-dispersive X-ray (EDS) analysis indicate that the products are under a mixed Mn(IO3)2/MnO2 phase. The morphology of the products can be controlled by altering the concentration, reaction time, and temperature. The growth mechanism of the nanostructures is proposed and discussed in detail. The optical properties of the 1D frog egg-like nanostructures are also examined using UV–Vis and photoluminescence (PL) spectrum.

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.

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 mu m and a length of 30 mu m. The obtained ZnO nanorod arrays are highly oriented. Their average diameter is around 50-100 nm, and their length is about 1 mu m. 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.

Porous and trigonal TiO(2) nanoflakes (p-TiO(2)) 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-TiO(2) has an anatase structure. Transmission electron microscopy images indicate that p-TiO(2) consists of sheet-like particles with numerous pores about 100nm 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-TiO(2) 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.

Graphitic C3N4 (g-C3N4) nanoparticles were prepared via a simple chemical synthesis route. The obtained g-C3N4 nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, and ultraviolet–visible diffusive reflectance spectroscopy. The g-C3N4 nanoparticles showed a strong absorbance within visible light. The sonocatalytic performance of the g-C3N4 nanoparticles in degrading methylene blue (MB) was also investigated. Compared with commercial P25 nanoparticles, the g-C3N4 nanoparticles possessed a relatively better sonocatalytic activity.

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.

We synthesized complex 3D CdCO3 pyramids consisting of arrays of oriented CdCO3 parallel tetrahedrons using controlled seeded growth and Cd2+ cations that selectively adsorb onto CdCO3 basal planes as the structure-directing agent. A growth mechanism of 3D CdCO3 pyramids was suggested and explained in detail. The optical properties of some of these 3D CdCO3 pyramids were demonstrated by infrared (IR), UV–vis diffuse reflectance (UV–vis), and photoluminescence (PL) spectra, suggesting potential applications in electronic and optoelectronic devices.

A visible-light S-doped BiSe photocatalyst was prepared by the solvothermal method in ethanediamine solvent. The photocatalyst was characterized by X-ray diffraction, UV–vis diffusive reflectance spectroscopy, and X-ray photoemission spectroscopy. Its activity was evaluated by photocatalytic oxidation of methylene blue under visible-light irradiation (λ>400nm). The reaction time and temperatures, as well as the precursor composition of S-doped BiSe, were found to exert great influence on photocatalytic activity.

A new method for the preparation of bimetal phosphides was reported. Bulk and SiO2-supported porous NiCoP were obtained from the direct thermal treatment of precursors containing nickel, cobalt salts, and sodium hypophosphite mixed mechanically under flowing nitrogen. Compared with traditional H2-temperature-programmed reduction method, the method developed provided a simple one-step way to produce bimetal phosphides with a relatively low temperature. In the report, a possible preparation mechanism was discussed to form NiCoP. The route and mechanism could also be applied to the preparation of other bimetal phosphides. In comparison with the Ni2P/SiO2 catalyst, the NiCoP/SiO2 showed a higher hydrodesulfurization activity for dibenzothiophene.

Antimony trioxide (Sb2O3) micro and nanostructures with various shapes have shown novel physical and chemical properties essential for technological applications. In the present study, we report the hydrothermal growth of a novel three-dimensional (3D) Sb2O3 grass-like microstructure by the direct reaction between SbCl3 and NaOH in a solution. The as-prepared 3D Sb2O3 microstructures consist of numerous microbelts with sharp tips and lengths of up to approximately 10μm, as well as widths of around 1.0μm. Other tunable architectures, including rose-like, cubic, belt-like, and bundle-like units, have also been prepared by changing the experimental conditions. The growth mechanism of Sb2O3 microstructures with grass shapes is speculated and analyzed in detail. Their optical properties are also surveyed using photoluminescence (PL) spectroscopy. A broad PL emission is revealed, suggesting potential applications in electronics and optoelectronics.

Bulk and supported Ni2P catalysts were prepared through a novel method using a solid mechanical mixture of Na(H2PO3)2 and NiCl2·6H2O in definite molar ratio as a precursor. The precursor was heated at 200–300°C for 1h in flowing N2 to form Ni2P catalysts. X-ray diffraction and X-ray photoelectron spectroscopy were used to study the formation of the phase. The mechanistic progress of Ni2P was studied using thermo gravimetry and the results indicate that NiCl2 is reduced by PH3 produced from decomposition of NaH2PO3 at 250°C. The dibenzothiophene (DBT) hydrodesulfurization (HDS) activity of the Ni2P/SiO2 catalysts was measured, and good activities were observed at different temperatures.