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Two 3d transition metal mononuclear complexes, [(Fe L 2)(ClO4)2]2·CH3CN (1) and (Co L 2)(ClO4)2·2CH3CN (2), have been prepared from a rigid tetradentate bpybox (L = 6,6′-bis(2,5-dihydrooxazol-4-yl)-2,2′-bipyridine) ligand. Single crystal X-ray diffraction analyses together with the help of calculations show that both compounds are octa-coordinate. Direct current magnetic studies reveal their significant magnetic anisotropy. Impressively, field-induced relaxation of magnetism is observed in the two complexes and the apparent anisotropy barriers are 14.1 K for 1 and 21.6 K for 2, respectively. Theoretical calculations reveal that two Fe(II) centers in 1 have small negative D values of −4.897 and −4.825 cm−1 and relatively small E values of 0.646 and 0.830 cm−1, indicating a uniaxial magnetic anisotropy. In contrast, the D and E values in the Co(II) center of 2 are 46.42 cm−1 and 11.51 cm−1, featuring a rhombic anisotropy. This work demonstrates that field-induced slow magnetic relaxation in 3d transition metal complexes with high coordination numbers can be manipulated through rigid ligand design. [ABSTRACT FROM AUTHOR]

Abstract: This study demonstrated a new approach of odorous gas treatment in a wet scrubbing-oxidation system with in situ generation of ferrate(VI), in which gaseous CH3SH can be quickly absorbed by aqueous alkaline solution and rapidly oxidized by liquid ferrate(VI) generated through electrochemical synthesis in situ. In this study, the electrochemical generation of ferrate(VI) in aqueous NaOH solution was studied and the experiments demonstrated that a maximum current efficiency to generate ferrate(VI) occurred at 14M NaOH concentration, while an applied current density of 14.06mAcm−2 was applied. Then the self-decomposition of ferrate(VI) in such strong alkaline solutions was studied, and the results showed that ferrate(VI) behaved more stable in the stronger alkaline solution. Furthermore, the reactivity of ferrate(VI) with CH3SH in this highly-concentrated NaOH solution was investigated under different reaction conditions as the first time. The experimental results confirmed that CH3SH can be fully oxidized by ferrate(VI) to sulphate ion as a final product. The second-order reaction model is suitable to describe the kinetics of CH3SH reaction with ferrate(VI) in the strong alkaline solution. Meanwhile, stoichiometry of ferrate(VI) reaction with CH3SH in aqueous solution was determined with a minimum molar ratio of 2.20:1 (Fe(VI):CH3SH) to destruct CH3SH effectively and a higher molar ratio of 4.53:1 to convert CH3SH to sulphate ion completely. The experiments also demonstrated that the NaOH concentration in aqueous solution would be a key parameter and the best performance of CH3SH removal was achieved at the optimum NaOH concentration of 6M under our experimental conditions due to an optimum balance between the oxidation potential of ferrate(VI) and its generation rate in this wet scrubbing-oxidation system. [Copyright &y& Elsevier]

Abstract: In this work, the homogeneous and heterogeneous degradations of diphenamid (DPA) in aqueous solution were conducted by direct photolysis with UVC (254nm) and by photocatalysis with TiO2/UVA (350nm), and the experimental results were compared. It was found that the homogeneous photolysis by UVC irradiation alone was quite efficient to degrade DPA up to 100% after 360min, but was very inefficient to mineralize its intermediates in terms of dissolved organic carbon reduction of only 8%. In contrast, the heterogeneous photocatalysis with TiO2/UVA showed relatively a lower degree of DPA degradation (51%), but a higher degree of its mineralization (11%) after 360min. These results reveal that the photocatalysis process has relatively poor selectivity to degrade different compounds including various intermediates from the DPA degradation, which is beneficial to its mineralization. In addition, over 20 intermediates were identified by LC–MS and 1H NMR analyses. Based on the identified intermediates, the reaction mechanisms and the detailed pathways of the DPA degradation by photolysis and photocatalysis were proposed, and are presented in this paper. [Copyright &y& Elsevier]

In this study titanium dioxide nanotube (TNT) arrays were prepared by an anodic oxidation process with post-calcination. The morphology and structure of the TNT films were studied by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Photocatalytic activity of the TNT films was evaluated in terms of the degradation of 2,3-dichlorophenol in aqueous solution under UV light irradiation. The effects of the nanotube structure including tube length and tube wall thickness, and crystallinity on the photocatalytic activity were investigated in detail. The results showed that the large specific surface area, high pore volume, thin tube wall, and optimal tube length would be important factors to achieve the good performance of TNT films. Moreover, the TNT films calcined at 500°C for 1h with the higher degree of crystallinity exhibited the higher photocatalytic activity than other TNT films calcined at 300 and 800°C. Consequently, these results indicate that the optimization of TiO2 nanotube structures is critical to achieve the high performance of photocatalytic reaction. [Copyright &y& Elsevier]

In this study, the highly-ordered TiO2 nanotube (TNT) arrays on titanium sheets were prepared by an anodic oxidation method. Under UV illumination, the TNT films demonstrated the higher photocatalytic activity in terms of 2,3-dichlorophenol (2,3-DCP) degradation in aqueous solution than the conventional TiO2 thin films prepared by a sol–gel method. The effects of dissolved oxygen (DO) and pH on the photocatalytic degradation of 2,3-DCP were investigated. The results showed that the role of DO in the 2,3-DCP degradation with the TNT film was significant. It was found that 2,3-DCP in alkaline solution was degraded and dechlorinated faster than that in acidic solution whereas dissolved organic carbon removal presented an opposite order in dependence of pH. In the meantime, some main intermediate products from 2,3-DCP degradation were identified by a 1H NMR technique to explore a possible degradation pathway. A major intermediate, 2-chlororesorcinol, was identified from the 2,3-DCP decomposition as a new species compared to the findings in previous reports. Photocatalytic deactivation was also evaluated in the presence of individual anions (, Cl−, , and ). The inhibition degree of photocatalytic degradation of 2,3-DCP caused by these anions can be ranked from high to low as >Cl− > > . The observed inhibition effect can be attributed to the competitive adsorption and the formation of less reactive radicals during the photocatalytic reaction. [Copyright &y& Elsevier]

Abstract: It is well known that the structural disorder of photocatalyst nanopowder usually leads to the enhanced scattering of free electrons, and thus reduces the electron mobility; in contrast, an ordered and interconnected nanostructure favors to improve electron transport, then achieving the higher photocatalytic efficiency. Therefore, in this study, a highly ordered and coaxial WO3/TiO2 nanostructure, consisting of nanotubes and nanorods, was prepared by a sol–gel template technique. The obtained photocatalysts were characterized by FE-SEM, XRD, UV–vis DRS and PL measurement. These photocatalysts exhibited a strong photoresponse in the visible region and a low PL emission. Their photoactivity was evaluated by means of the degradation of 2,3-dichlorophenol (2,3-DCP) under visible light irradiation. Experimental results show that while there was no obvious degradation of 2,3-DCP with the TiO2 nanotubes as photocatalysts, ∼53% of degradation degree in 300min was obtained with the WO3/TiO2 nanocomposites. This significant activity should be attributed to the role of WO3 loaded in TiO2 nanotubes. The WO3 loading not only facilitates the effective separation of photogenerated carriers occurring on the TiO2 surface, but also enhances the surface hydroxyl groups and surface acidity, thus improving the overall photocatalytic performance. [Copyright &y& Elsevier]

Two 3d transition metal mononuclear complexes, [(FeL 2 )(ClO 4 ) 2 ] 2 ·CH 3 CN (1) and (CoL 2 )(ClO 4 ) 2 ·2CH 3 CN (2), have been prepared from a rigid tetradentate bpybox (L = 6,6'-bis(2,5-dihydrooxazol-4-yl)-2,2'-bipyridine) ligand. Single crystal X-ray diffraction analyses together with the help of calculations show that both compounds are octa-coordinate. Direct current magnetic studies reveal their significant magnetic anisotropy. Impressively, field-induced relaxation of magnetism is observed in the two complexes and the apparent anisotropy barriers are 14.1 K for 1 and 21.6 K for 2, respectively. Theoretical calculations reveal that two Fe(II) centers in 1 have small negative D values of -4.897 and -4.825 cm -1 and relatively small E values of 0.646 and 0.830 cm -1 , indicating a uniaxial magnetic anisotropy. In contrast, the D and E values in the Co(II) center of 2 are 46.42 cm -1 and 11.51 cm -1 , featuring a rhombic anisotropy. This work demonstrates that field-induced slow magnetic relaxation in 3d transition metal complexes with high coordination numbers can be manipulated through rigid ligand design.