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Four nanostructural nickel(II) coordination polymers {[Ni(ttpa)(1,4-ndc)(H 2 O) 2 ]·2H 2 O} n (1), {[Ni(ttpa)(1,3-bda)]·2H 2 O·DMF} n (2·2H 2 O·DMF), {[Ni(ttpa)(1,4-bdc)]·H 2 O} n (3) and {[Ni(ttpa)(aip)(H 2 O)]·3H 2 O} n (4·3H 2 O) were synthesized using hydrothermal and sonochemical methods (ttpa = tris(4-(1,2,4-triazol-1-yl)phenyl)amine, 1,4-ndc = 1,4-naphthalenedicarboxylate, 1,3-bda = 1,3-benzenediacetate, 1,4-bdc = 1,4-benzenedicarboxylate, aip = 5-aminoisophthalate), and characterized by elemental analysis, IR spectra, scanning electron microscopy, single-crystal and powder X-ray diffraction analysis, optical band gaps, VB XPS spectra and luminescence. The effects of sonication power, time and frequency on the size and morphology of nano-sized 1-4 have been studied. 1 exhibits an unusual 2D + 2D → 3D inclined polycatenated motif based on the (3,3)-coordinated 6 3 -hcb topology. 2 shows a (3,4)-coordinated 2D network of the bey topology. 3 presents a rare example of the 4-fold interpenetrating array of (3,5)-coordinated 3D network belonging to the 35T1 topology type. 4 displays an unusual 2D → 3D polythreaded network based on 2D sql networks. 1-4 exhibit luminescent emissions at 409, 399, 413 and 402 nm, respectively. 1-4 are semiconducting in nature, with E g of 2.12 eV (1), 2.34 eV (2), 2.32 eV (3), and 2.47 eV (4). 1-4 are good catalysts for the degradation of MB under visible light irradiation. The effects of the size and morphology of nano-sized 1-4 on the photocatalytic efficiencies were studied. The higher sonication frequency obtains uniform and smaller nano-sized coordination polymers which have higher catalytic efficiencies., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Bismuth selenide (Bi2Se3) has attracted great attention as one of typical topological insulator materials. In this work, size-controllable Bi2Se3 nanoflowers (NFs) composed of numerous thin nanosheets are successfully synthesized by a hot-solution injection method under mild conditions. The structure and morphology of the obtained Bi2Se3 NFs are characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopic (EDS), and selected area electron diffraction (SAED) techniques. The reaction temperature, time, and surfactant ratio (oleylamine/oleic acid) affect the phase purity and morphology of Bi2Se3 samples. Based on the experimental results, the formation mechanism of Bi2Se3 nanoflowers is proposed. Meanwhile, the photocatalytic behavior of the as-prepared Bi2Se3 nanoflowers in the presence of H2O2 is explored and it is found that the degrading rate of RhB can reach 93% after 2 h visible light irradiation. [ABSTRACT FROM AUTHOR]

Bismuth selenide (Bi2Se3) has attracted great attention as one of typical topological insulator materials. In this work, size-controllable Bi2Se3 nanoflowers (NFs) composed of numerous thin nanosheets are successfully synthesized by a hot-solution injection method under mild conditions. The structure and morphology of the obtained Bi2Se3 NFs are characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopic (EDS), and selected area electron diffraction (SAED) techniques. The reaction temperature, time, and surfactant ratio (oleylamine/oleic acid) affect the phase purity and morphology of Bi2Se3 samples. Based on the experimental results, the formation mechanism of Bi2Se3 nanoflowers is proposed. Meanwhile, the photocatalytic behavior of the as-prepared Bi2Se3 nanoflowers in the presence of H2O2 is explored and it is found that the degrading rate of RhB can reach 93% after 2 h visible light irradiation. [ABSTRACT FROM AUTHOR]

By using ginkgo leaves (GL) as template and Zn(CH₃COO)₂∙2H₂O as Zn source, a series of ZnO samples with special morphology were prepared via a template-assisted two-steps method without adding any other additives. The degradation of the dye MB was used to evaluate the photocatalytic property of the as-prepared samples. The results showed that when a proper amount of the template was used, a 3D nanoarchitectural ZnO hollow sphere with porous sphere shell assembled by well-distributed nanoparticles was obtained and its photocatalytic activity was much higher than that of ZnO nanoparticles. The special morphology of the sample was herein considered to be very helpful for highly efficient adsorption and activation of reactant molecules by multi-times adsorption-desorption-adsorption, efficient absorption of irradiation light by repeated absorption-reflection-absorption, and efficient separation of the photogenerated e - - h ⁺ pairs. In addition, the formation of 3D structure of sample ZnO was also discussed.

A new coordination polymer (CP), formulated as [Cd(L)(DCTP)] n (1) (L=1,1'-(1,4-butanediyl)bis(2-methylbenzimidazole), H 2 DCTP=2,5-dichloroterephthalic acid), was synthesized under hydrothermal conditions and the performance as luminescent probe was also investigated. Single-crystal X-ray diffraction reveals CP 1 is a 3D 3-fold interpenetrated dia network with large well-defined pores. It is found that CP 1 revealed highly sensitive luminescence sensing for Fe 3+ ions in acetonitrile solution with a high quenching efficiency of K SV =2541.238L·mol -1 and a low detection limit of 3.2μM (S/N=3). Moreover, the photocatalytic efficiency of 1 for degradation of methylene blue could reach 82.8% after 135min. Therefore, this coordination polymer could be viewed as multifunctional material for selectively sensing Fe 3+ ions and effectively degrading dyes., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A nanoparticle of cobalt(II) coordination polymer (CP), [Co(L)(npht)] n (1) (H 2 npht=4-nitrophthalic acid, L=1,3-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene) and its nanocomposite (Ag/CP 1) were obtained by the sonochemical approach and characterized by IR, elemental analysis, thermogravimetric analyses (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRPD). CP 1 shows a 1D double chain containing two different helical chains, which is further extended into a two-dimensional supramolecular framework by C-H⋯O hydrogen bonding interactions. The photoluminescence properties and photocatalytic properties of the nanoparticles of CP 1 and Ag/CP 1 on the degradation of methylene blue (MB) were investigated, Ag/CP 1 exhibited excellent photocatalytic activity under UV and visible light, which can be attributed to the strong interactions between Ag nanorods and CP 1, which lead to electron-hole pair separation between Ag nanorods and CP 1. In addition, the photocatalytic mechanism is also carried out by introducing t-butyl alcohol (TBA) as a widely used ·OH scavenger. The influence of ultrasound irradiation time and power on the morphology and size of the nanostructure CP 1 were studied. The results indicated that a decrease in time and an increase in power led to a decrease of particle size., (Copyright © 2017 Elsevier B.V. All rights reserved.)

TiO2 films doped with ZnFe2O4 were prepared by a sol–gel method. The crystalline structure, photocatalytic efficiency and optical absorption band were investigated using X-ray diffraction and Ultraviolet-Visible spectrometer. The doping of ZnFe2O4 improves the photocatalytic efficiency and broadens the optical absorption band of TiO2 films. The photocatalytic efficiency of TiO2 films increases from 12 to 32% with the presence of ZnFe2O4. The exciting wavelength of TiO2 films shifts about 20 nm to the visible light regions when the molar ratio of ZnFe2O4 is 2%. [ABSTRACT FROM AUTHOR]

Nanostructures of a new Co(II) coordination polymer (CP), [Co(Hbibp)(nbta)] n (1), (bibp=4,4'-bis(1-imidazolyl)biphenyl, H 3 nbta=5-nitro-1,2,3-benzenetricarboxylic acid) was synthesized by a sonochemical method. The nano-sized CP 1 was characterized by elemental analysis, IR spectroscopy, X-ray powder diffraction and scanning electron microscopy (SEM). Structural analysis show that CP 1 exhibits a 1D chain structure with a 3-connected SP 1-periodic net (4,4)(0,2) topology, which can be further extended into a 2D supramolecular layer by the NH⋯O hydrogen bond interactions. The thermal stability for CP 1 as bulk and nanoparticles were investigated. The photoluminescence properties and electrochemical behavior for nano-sized CP 1 have also been explored. Moreover, nano-sized CP 1 shows high photocatalytic activities for the degradation of MB under UV irradiation and the photodegradation process is mainly caused by OH radicals. Effects of the sonication time and ultrasonic power on the morphology and size of nanoparticles were studied., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Nanoparticles of two silver(I) coordination polymers (CPs), [Ag 2 (L1) 2 (DCTP)] n (1) and [Ag 2 (L2)(DCTP)] n (2) (L1=1,3-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene, L2=1,4-bis(benzimidazol-1-yl)-2-butene, H 2 DCTP=2,5-dichloroterephthalic acid), were synthesized by the sonochemical approach and hydrothermal method. Both CPs were characterized by elemental analysis, IR spectra, single-crystal X-ray diffraction, scanning electron microscopy (SEM), and thermogravimetric analyses (TGA). CP 1 exhibits a 2D 4-connected sql net with the point symbol {4 4 .6 2 }. While CP 2 displays a 2D 3,4-connected 3,4L13 net with the point symbol {4.6 2 } 2 {4 2 .6 2 .8 2 }. The structural diversity indicates that semi-rigid bis(benzimidazole) co-ligands play important roles in tuning the structures of the mixed Ag(I) CPs. The ultrasound irradiation time, temperature, and power showed significant effects on the morphology and growth process of the nanoparticles of two silver(I) CPs. The luminescence and photocatalytic properties of the nanoparticles of CPs 1-2 on the degradation of methyl blue (MB) were also investigated in detail., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This study reported a novel approach to optimize the photocatalytic property of anatase TiO 2 particles by delaminating their outer surface into highly reactive nanosheets via the sono-assisted exfoliation method. To modify the surface, TiO 2 particles were dispersed in aqueous solution of 10M sodium hydroxide (NaOH) and tetrabutylammonium hydroxide (TBAOH), followed by irradiation with high intensity ultrasonic wave (20kHz, 150W/cm 2 ) for 60min. The intercalation and exfoliation processes were accelerated with the driving force of the extreme acoustic cavitation leading to the delamination of TiO 2 nanosheets with highly reactive exposed {001} facets from the mother TiO 2 crystals. The presence of TBAOH increased yield of nanosheets formation and stabilized the nanosheet structure. The unique morphology of the surface modified TiO 2 particles provided benefits in increasing the specific surface area and lowering the optical band gap energy (E g ) and electron-hole recombination rate resulting in an enhancement of methylene blue dye degradation efficiency. The surface modification of TiO 2 particles by the sono-assisted exfoliation method can optimize the photocatalytic activity by yielding synergetic effects of the high surface reactive sites of the nanosheets and the high degree of crystallinity of the bulk structure., (Copyright © 2017 Elsevier B.V. All rights reserved.)

More recently, the biological colonization of stone heritage and consequently its biodeterioration has become the focus of numerous studies. Among all microorganisms, fungi are considered to be one of the most important colonizers and biodegraders on stone materials. This is why the development of new antifungal materials requires immediate action. ZnMgO nanoparticles (NPs) have several exciting applications in different areas, highlighting as an efficient antimicrobial agent for medical application. In this research, the application of Zn-doped MgO (Mg 1-x Zn x O, x = 0.096) NPs obtained by sol-gel method as antifungal coatings on dolomitic and calcitic stones has been explored as a means to develop effective protective coatings for stone heritage. Moreover, the photocatalytic and antifungal activity of Mg 1-x Zn x O NPs were comparatively studied with single ZnO and MgO NPs. Thus, compared to the MgO and ZnO nanomaterials, the Mg 1-x Zn x O NPs exhibited an enhanced photocatalytic activity. After UV irradiation for 60 min, 87% methylene blue was degraded over Zn-doped MgO NPs, whereas only 58% and 38% of MB was degraded over ZnO and MgO NPs, respectively. These nanoparticles also displayed a better antifungal activity than that of single pure MgO or ZnO NPs, inhibiting the growth of fungi Aspergillus niger, Penicillium oxalicum, Paraconiothyrium sp., and Pestalotiopsis maculans, which are especially active in the bioweathering of stone. The improved photocatalytic and antifungal properties detected in the Mg 1-x Zn x O NPs was attributed to the formation of crystal defects by the incorporation of Zn into MgO. The application of the MgO- and Zn-doped MgO NPs as protective coatings on calcareous stones showed important antifungal properties, inhibiting successfully the epilithic and endolithic colonization of A. niger and P. oxalicum in both lithotypes, and indicating a greater antifungal effectiveness on Zn-doped MgO NPs. The use of Zn-doped MgO NPs may thus represent a highly efficient antifungal protection for calcareous stone heritage.

We report the facile synthesis of a well-organized meso-macroporous TiO2/SiO2 thin film with high porosity and good interconnectivity from a binary mixture (i.e., titania precursor and polymer template). Our process is based on self-assembly of the amphiphilic rubbery comb copolymer, poly(dimethylsiloxane)-g-poly(oxyethylene methacrylate) (PDMS-g-POEM) with titanium tetraisopropoxide (TTIP). SiO2 is self-provided by thermal oxidation of PDMS chains during calcination under air. The selective, preferential interaction between TTIP and the hydrophilic POEM chains was responsible for the formation of well-organized TiO2/SiO2 films, as supported by transmission electron microscopy, scanning electron microscopy, X-ray photospectroscopy, and X-ray diffraction analyses. We investigated in detail the effect of precursor content, solvent type, and polymer concentration on thin film morphology. Photodegradation of methyl orange by the well-organized meso-macroporous TiO2/SiO2 film was greater than that of a dense TiO2 film prepared without PDMS-g-POEM as well as a SiO2-etched TiO2 film. These results indicate that the well-organized structure and SiO2 doping of the TiO2 film play a pivotal role in enhancing its photocatalytic properties.

Novel photocatalysts Gd₂FeSbO₇, Gd₂InSbO₇ and Gd₂YSbO₇ were synthesized by the solid state reaction method for the first time. A comparative study about the structural and photocatalytic properties of Gd₂MSbO₇ (M = Fe, In, Y) was reported. The results showed that Gd₂FeSbO₇, Gd₂InSbO₇ and Gd₂YSbO₇ crystallized with the pyrochlore-type structure, cubic crystal system and space group Fd3m. The lattice parameter a for Gd₂FeSbO₇, Gd₂InSbO₇ or Gd₂YSbO₇ was 10.276026 Å, 10.449546 Å or 10.653651 Å. The band gap of Gd₂FeSbO₇, Gd₂InSbO₇ or Gd₂YSbO₇ was estimated to be 2.151 eV, 2.897 eV or 2.396 eV. For the photocatalytic water-splitting reaction, H₂ or O₂ evolution was observed from pure water with Gd₂FeSbO₇, Gd₂InSbO₇ or Gd₂YSbO₇ as catalyst under visible light irradiation (wavelength > 420 nm). Moreover, H₂ or O₂ also spilt by using Gd₂FeSbO₇, Gd₂InSbO₇ or Gd₂YSbO₇ as catalyst from CH₃OH/H₂O or AgNO₃/H₂O solutions under visible light irradiation (λ > 420 nm). Gd₂FeSbO₇ showed the highest activity compared with Gd₂InSbO₇ or Gd₂YSbO₇. At the same time, Gd₂InSbO₇ showed higher activity compared with Gd₂YSbO₇. The photocatalytic activities were further improved under visible light irradiation with Gd₂FeSbO₇, Gd₂InSbO₇ or Gd₂YSbO₇ being loaded by Pt, NiO or RuO₂. The effect of Pt was better than that of NiO or RuO₂ for improving the photocatalytic activity of Gd₂FeSbO₇, Gd₂InSbO₇ or Gd₂YSbO₇.

We present a straightforward method for simultaneously enhancing the electrical conductivity, environmental stability, and photocatalytic properties of graphene films through one-step transfer of CVD graphene and integration by introducing TiO2/graphene oxide layer. A highly durable and flexible TiO2 layer is successfully used as a supporting layer for graphene transfer instead of the commonly used PMMA. Transferred graphene/TiO2 film is directly used for measuring the carrier transport and optoelectronic properties without an extra TiO2 removal and following deposition steps for multifunctional integration into devices because the thin TiO2 layer is optically transparent and electrically semiconducting. Moreover, the TiO2 layer induces charge screening by electrostatically interacting with the residual oxygen moieties on graphene, which are charge scattering centers, resulting in a reduced current hysteresis. Adsorption of water and other chemical molecules onto the graphene surface is also prevented by the passivating TiO2 layer, resulting in the long term environmental stability of the graphene under high temperature and humidity. In addition, the graphene/TiO2 film shows effectively enhanced photocatalytic properties because of the increase in the transport efficiency of the photogenerated electrons due to the decrease in the injection barrier formed at the interface between the F-doped tin oxide and TiO2 layers., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)