Synthesis, characterization and crystal structure of a novel Sr (II)- Cu(II) complex, a precursor to produce catalyst of Cu-Sr/SiO2, applicable for hydrogen production

A new hetero-dinuclear complex [(Sr(OH2)6Cu(H2O)4 Sr2 (dipic)4(OH2)2]n.nH2O (CS) that dipic2- is pyridine-2,6-dicarboxylato has been synthesized under ultrasonic irradiation. The structure of the CS complex has been fully characterized by elemental analysis, Fourier transforms infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), differential thermal analysis (DTA) and single-crystal X-ray diffraction (SC-XRD). The results of crystallography analysis revealed that this complex crystallizes in a triclinic system with space group P -1. It also confirms the large number of H-O ... O hydrogen bonds play a key role in the creation of the 3D network. The Sr-Cu/SiO2 nano-catalyst was prepared by thermal decomposition of CS complex at 600ºC in the presence of silica support. In addition, reference catalysts of Cu-Sr/SiO2 were prepared by co-precipitation and impregnation methods and characterized by FT-IR spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and specific surface area (BET). The results of these studies show that the catalyst obtained by the thermal decomposition of the CS complex has smaller particle size and larger specific surface area than the two reference catalysts. In order to produce hydrogen gas, a water-gas shift reaction (WGS) was performed on the surface of Cu-Sr/SiO2 nanocatalysts in the temperature range of 300-420ºC. Examination of the effect of temperature shows that at 380ºC the catalytic activity of all three catalysts is at its highest. The highest catalytic performance was achieved by nanocatalyst that derived from CS complex. This high catalytic performance can be attributed to the physicochemical properties of this catalyst such as smaller particle size and higher specific surface area

Synthesis and molecular structure of a new metal-organic complex based on Zn(II) and quinoline, a precursor for fabrication of ZnO nanoparticles applicable in the photocatalytic reactions

A novel zinc-based pseudohalide metal–organic complex formulated as [Zn(NCS)4].2(C9H8N) (1) (C9H7N = quinoline) has been synthesized by a sonochemical process. The structure of 1 has been characterized by elemental analysis, atomic absorption spectroscopy (AAS), Fourier-transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), differential thermal analysis (DTA) and single-crystal X-ray diffraction (SC-XRD). Complex 1 crystallizes in a monoclinic system, space group P21/c with unit cell parameters a = 8.5406(6) Å, b = 35.6706(17) Å, c = 8.6418(6) Å, and β = 107.093(7)º. Its structure consists of a tetrahedral [Zn(NCS)4] complex and two molecules of quinoline. In the crystal lattice of complex 1, the [Zn(NCS)4]2- complex anion is stacked in hexagonal-like columns forming 2D layers, each column includes an organic chain formed from one of [C9H8N]+ organic cations where the other cation separates between layers. The hydrogen bonds and some weak interactions are responsible for linking and strengthening the whole structure. Magnetic measurements revealed that complex 1 is a weak ferromagnet at room temperature. Nanoparticles of ZnO have been successfully synthesized by thermal decomposition of 1 and characterized by FT-IR spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller N2 adsorption-desorption analysis. The photocatalytic activity of commercial ZnO and as-obtained ZnO was investigated for degradation of methyl orange (MO) and Bisphenol A (BPA) under UV irradiation. The results revealed that the synthetic ZnO had higher catalytic activity than the commercial ZnO and the highest degradation occurs at pH = 4 and pH = 8 for MO and BPA, respectively.The financial support from University of Zabol (Grant No-9618-39), Spanish Ministerio de Economía y Competitividad (MAT2016-78155-C2-1-R and FPI grant BES-2011-046948 to MSM.A.), Gobierno del Principado de Asturias (GRUPIN-IDI/2018/170) are acknowledged