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Abstract Recently, global-scale efforts have been devoted to development of eco-friendly and green technologies to remediate pollution of water resources. In line with global efforts, this study prepared visible light active bismuth molybdate hollow microspheres (Bi 2 MoO 6 HMSs) using carbon microspheres, as the synthesis template. The utilized carbon microspheres were synthesized from fructose through a simple one-step hydrothermal process. The structural and spectrophotometric results indicated that the prepared HMSs have an orthorhombic crystal structure with the Brunauer–Emmett–Teller (BET) surface area of 117.8 m2 g−1 and the band gap energy of 2.45 eV. The Bi 2 MoO 6 HMSs were then applied to lab-scale photodegradation of two anionic and cationic dyes under visible light. The photocatalytic studies declared that the HMSs are highly efficient in photodegradation of the methyl orange (MO; cationic) and methylene blue (MB; anionic) dyes under ultraviolet and visible light irradiations in aqueous solutions. The photocatalytic performance of the HMSs was also compared with the activity of the P25 photocatalyst. The results demonstrated that the Bi 2 MoO 6 HMSs are five times more active than the P25 particles under visible light. Finally, with respect to the impact of various scavengers, •O 2 −, h+ and •OH were found to play key roles in the photodegradation process. Graphical abstract Image 104716 Highlights • Bi 2 MoO 6 HMSs was prepared for the first time through application of carbon spheres. • The HMSs mesoporous structure exhibited high specific surface area. • Bi 2 MoO 6 HMSs showed excellent visible-light-driven photocatalytic activity. • Mesoporous Bi 2 MoO 6 HMSs were chemically stable and recycled easily. • Effects of various scavengers and the reaction mechanism were investigated. [ABSTRACT FROM AUTHOR]

In this letter, we establish some exact solutions for complex nonlinear Klein–Gordon equation u tt − p 2 u xx + qu + r | u | 2 u = 0 , where pqr ≠ 0 . The ( G ′/ G )-expansion method is used to construct exact periodic and soliton solutions of this equation. Our work is motivated by the fact that the ( G ′/ G )-expansion method provides not only more general forms of solutions but also periodic and solitary waves. As a result, hyperbolic function solutions, trigonometric function solutions and rational function solutions with parameters are obtained and shown in some figures. These solutions may be important for the explanation of some practical physical and engineering problems. [ABSTRACT FROM AUTHOR]

In the present paper a pure phase of the copper chromite spinel nanoparticles (CuCr 2 O 4 SNPs) were synthesized via the sol–gel route using citric acid as a complexing agent. Then, the CuCr 2 O 4 SNPs has been characterized by field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). In the next step, with the addition of Cu–Cr–O nanoparticles (NPs), the effects of different parameters such as Cu–Cr–O particle size and the Cu/Cr molar ratios on the thermal behavior of Cu–Cr–O NPs + AP (ammonium perchlorate) mixtures were investigated. As such, the catalytic effect of the Cu–Cr–O NPs for thermal decomposition of AP was evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA/DSC results showed that the samples with different morphologies exhibited different catalytic activity in different stages of thermal decomposition of AP. Also, in the presence of Cu–Cr–O nanocatalysts, all of the exothermic peaks of AP shifted to a lower temperature, indicating the thermal decomposition of AP was enhanced. Moreover, the heat released (Δ H ) in the presence of Cu–Cr–O nanocatalysts was increased to 1490 J g −1 . [ABSTRACT FROM AUTHOR]

Abstract: Lanthanum ferrite nanoparticles (LaFeO3 NPs) with light absorption properties in the visible region were successfully synthesized in CTAB (cetyltrimethyl ammonium bromide) emulsion nanoreactors at room temperature. The morphology, size, structure, elemental composition, and optical properties of these particles were characterized by field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence (XRF), and ultraviolet–visible absorption (UV–Vis) spectroscopy. Through this method, highly crystalline and well-dispersed perovskite LaFeO3 NPs with a phase-pure were successfully obtained. The band gap energy (E g) of the LaFeO3 NPs was calculated by UV-Vis spectroscopy at the wavelength of about 517nm and is observed to have a value of 2.43eV. The photocatalytic activities of LaFeO3 NPs were evaluated by the degradation of toluidine blue O (TBO, used as a probe) dye under visible light irradiation, which exhibits a high photocatalytic TBO dye degradation activity as compared to the commercial P-25 titania powder. This phenomenon is due to smaller band gap energy and changing from bulk to nanostructure. The higher photocatalytic activity is also related to the photo absorption. [Copyright &y& Elsevier]

Abstract: The metal nanoparticles (NPs) have been prepared using a water-in-oil microemulsion system of water/dioctyl sulfosuccinate sodium salt (aerosol-OT, AOT)/isooctane at 25 °C. Since the NPs produced in this system can endure forcing conditions (100 °C), this system has been used for the synthesis of nano-catalysts in the Heck reactions. FE-SEM, DLS, and UV/vis analyses have been used to characterize the surface morphology, size, and proof of the formation of all the prepared metal NPs, respectively. In addition, the effects of some reaction parameters (here, bases and solvents) were optimized. Differences in the catalytic properties of the synthesized NPs have also been investigated. Consequently, the Pd/Cu (4:1) bimetallic NP showed the highest activity in the C–C coupling reaction of the iodobenzene with the styrene, thus it is employed as the superior catalyst in this study. Therefore, the Pd/Cu (4:1) bimetallic NPs were further investigated using TEM and XRD analyses. This catalyst system is also reusable for six runs with very negligible reduction in the efficiency. [Copyright &y& Elsevier]

Abstract: In this work, the (G′/G)-expansion method with the aid of Maple is applied to construct more general exact solutions of the coupled Boussinesq equations, where the French scientist Joseph Valentin Boussinesq (1842-1929) described in the 1870s model equations for the propagation of long waves on the surface of water with a small amplitude. Each of the obtained solutions, namely hyperbolic function solutions, trigonometric function solutions and rational function solutions contain an explicit linear function of the variables in the considered equation. It is shown that the proposed method provides a powerful mathematical tool for solving nonlinear wave equations in mathematical physics and engineering problems. [Copyright &y& Elsevier]

Abstract: In this work, the -expansion method is applied for constructing more general exact solutions of the three nonlinear evolution equations with physical interest namely, the Tzitzéica equation, the Dodd–Bullough–Mikhailov (DBM) equation and the Tzitzéica–Dodd–Bullough (TDB) equation. Our work is motivated by the fact that the -expansion method provides not only more general forms of solutions but also periodic and solitary waves. If we set the parameters in the obtained wider set of solutions as special values, then some previously known solutions can be recovered. The method appears to be easier and faster by means of a symbolic computation system. [Copyright &y& Elsevier]

Abstract: In this paper, the Differential Transformation Method (DTM) is employed to obtain the numerical/analytical solutions of the Burgers and coupled Burgers equations. We begin by showing how the differential transformation method applies to the linear and nonlinear parts of any PDE and give some examples to illustrate the sufficiency of the method for solving such nonlinear partial differential equations. We also compare it against three famous methods, namely the homotopy perturbation method, the homotopy analysis method and the variational iteration method. These results show that the technique introduced here is accurate and easy to apply. [Copyright &y& Elsevier]

Abstract: Recently, in the paper [Manlin Xie, Xuanhao Ding, A new method for a generalized Hirota–Satsuma coupled KdV equation, Appl. Math. Comput. 217 (17) (2011) 7117–7125], the authors have applied the two–dimensional differential transform method to approximate the travelling-wave solutions of generalized Hirota–Satsuma coupled KdV equation subject to two different initial conditions. We checked the second initial condition and related exact solution and found that it does not satisfy the original equation. It seems that a typographical error in the initial condition has caused a mistake in the related exact travelling wave solution. The correct solutions have been studied by DTM and RDTM in Abazari and Abazari (2012) [Reza Abazari, Malek Abazari, Numerical simulation of generalized Hirota–Satsuma coupled KdV equation by RDTM and comparison with DTM, Commun. Nonlin. Sci. Numer. Simulat. 17 (2) (2012) 619–629]. [Copyright &y& Elsevier]

This study has sought to draw a comparison among the nickel oxide nanostructures (NSs) with multiple shapes in terms of their photocatalytic properties. These NSs have been synthesized using a set of wet chemical methods (thermal-decomposition, sol–gel, hydrothermal, and emulsion nano-reactors), for which a similar precursor has been considered. For evaluation of the photocatalytic properties of the suggested NSs, methyl orange (MeO) solution photocatalytic degradation has been estimated based on UV–Vis spectroscopy. As shown by our results, the photocatalytic efficiency of the prepared NSs is highly dependent upon the shape of the corresponding structures. In this context, the emulsion nano-reactors (ENRs) method has been developed for the synthesis of pure nickel oxide nanoparticles (NPs) with unaggregated, quite spherical, and homogeneous NPs at environmental conditions. Compared with the other methods in this work, ENRs method shows high photocatalytic efficiency in the MeO dye decomposition. [ABSTRACT FROM AUTHOR]