Highly-efficient photocatalyst based on Bi2WO6/SnS heterostructure was prepared via a surface functionalization method using 3-mercaptopropionic (MPA) as the surface functionalizing agent. Compared to bare Bi2WO6 and SnS nanoparticles, the as-formed Bi2WO6/SnS heterostructure exhibits enhanced photocatalytic activity for the degradation of Rhodamine B (Rh B). Photoluminescence and photocurrent measurements demonstrate that the enhanced photocatalytic activity during the photocatalytic process is closely related to the enhanced electron–hole separation efficiency. The photocatalytic activity of the as-formed Bi2WO6/SnS heterostructure can be perfectly remained even after being used for five times, showing excellent durability during the photocatalytic process. The influence of pH and inorganic ions are systematically investigated. And the optimum pH for the photocatalytic process is determined to be 6. The addition of chloride ion will exert negative effect on the photodegradation process of Rh B. The mechanism of photodegradation process was investigated by exploring the quenching effects of different scavengers and the results suggest that the reactive holes play the major role in the photodegradation process of Rh B.A type II heterostructre (Bi2WO6/SnS) is synthesized by a surface functionalization method. The as-obtained heterostructure exhibits enhanced photocatalytic activity toward the degradation of Rh B, which may result from the bigger surface area, broader light absorption region and higher charge separation efficiency.

The formation of type II heterostructures is proved to be an effective method to improve the photocatalytic performance of semiconductors. In this report, a surface functionalization method using 3-mercaptopropionic acid (MPA) as the surface functionalizing agent was adopted for the fabrication of Bi2WO6/MS (M = Cd and Zn) heterostructures. The composition and microstructures of the as-prepared heterostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and X-ray photoelectron spectroscopy (XPS). The as-prepared Bi2WO6/CdS and Bi2WO6/ZnS heterostructures exhibit enhanced photocatalytic activities for the degradation of Rhodamine B (Rh B) as compared to pure Bi2WO6, CdS, ZnS nanoparticles and Degussa P25. The enhanced photocatalytic activities of the as-prepared heterostructures may relate to the effective electron–hole separation during the photocatalytic process. A series of scavengers (benzoquinone for O2˙−, ammonium oxalate for h+, AgNO3 for e−, and t-BuOH for ˙OH) were employed to investigate the possible mechanism of the photocatalytic process. The results clearly indicate that the photogenerated holes are the main active species during the photocatalytic process.

•The adsorbent of Co0.6Fe2.4O4 micro-particles were synthesized by a simple method.•The adsorbent shows relatively high adsorption capacity for the removal of Pb(II).•The Pb(II) adsorbed Co0.6Fe2.4O4 micro-particles could be easily isolated by magnetic separation.•The adsorption kinetics could be fitted well by the pseudo-second-order model.•The Pb(II) adsorption onto Co0.6Fe2.4O4 micro-particles is endothermic and spontaneous.Magnetically separable adsorbent composed of Co0.6Fe2.4O4 micro-particles were successfully prepared by thermal decomposition of the Co0.6Fe2.4C2O4·2H2O. The as-prepared samples were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray energy dispersive spectroscopy (EDS). The specific surface area of the sample is determined to be 97.155 m2 g−1, with uniform pore size distribution centering at about 7.432 nm. The as-obtained Co0.6Fe2.4O4 micro-particles exhibits ferromagnetic behavior at room temperature, which makes it magnetically separable under external magnetic field. The as-obtained magnetic Co0.6Fe2.4O4 micro-particles exhibits excellent adsorption capacity and high adsorption rate for the removal of Pb(II) in aqueous solution. The maximum adsorption capacity of Pb(II) is up to 80.32 mg g−1 and 88% of the Pb(II) can be removed within the initial 30 min of contact time. The effects of contact time, initial pH, ionic strength and temperature on the adsorption behavior of Pb(II) were systematically investigated. The kinetics of the adsorption process follows the pseudo-second-order model and is controlled by the film diffusion process. The equilibrium data can be fitted well using the Langmuir isotherm model, suggesting that the uptake of Pb(II) ions is a mono-layer adsorption process. Meanwhile, the mean free energy E calculated by D-R isotherm model demonstrates that the adsorption process is implemented via the chemical ion-exchange mechanism. The thermodynamic studies illustrate that the adsorption process is endothermic and spontaneous in nature.

Two new coordination polymers, [Zn(mpba)2]n (1) and [Cd(H2O)(mpba)2]n (2), have been prepared by reactions of M(NO3)2·6H2O (M = Zn for 1, Cd for 2) with an unsymmetric 3-methyl-5-(pyridin-4-yl)benzoic acid (Hmpba) under hydrothermal condition. Both complexes 1 and 2 were characterized by elemental analyses, FT-IR spectra and single-crystal X-ray diffraction analyses. Structural analyses reveal that complex 1 displays a 2D network with sql topology, while complex 2 exhibits a 3D framework with 2-fold interpenetrated cds topology. Furthermore, the thermal and photoluminescent properties of complexes 1 and 2 have also been investigated in the solid state.Two new d10 metal (ZnII/CdII) coordination polymers with 3-methyl-5-(pyridin-4-yl)benzoic acid have been hydrothermally prepared and structurally characterized. Complexes 1 and 2 show sql and 2-fold interpenetrated cds topologies, respectively. The thermal and photoluminescent properties of complexes 1 and 2 have also been investigated in the solid state.Highlights► Complexes 1 and 2 have been hydrothermally assembled by the unsymmetric ligand 3-methyl-5-(pyridin-4-yl)benzoic acid. ► Complexes 1 and 2 show sql and 2-fold interpenetrated cds topologies, respectively. ► The high thermostability and intense photoluminescence for 1 and 2 have been observed in the solid state.

An aroyl acylamide compound, tetramethyl 5,5′-(terephthaloylbis(azanediyl))-diisophthalate (1), has been prepared by nucleophilic substitution reaction of dimethyl 5-aminoisophthalate and terephthaloyl chloride, and characterized by elemental analysis, FT-IR, 1H-NMR, ESI–MS and single-crystal X-ray diffraction. The crystal of 1·2DMF belongs to monoclinic space group P2/c with a = 21.609(2) Å, b = 4.060(1) Å, c = 21.606(2) Å, β = 112.805(1)°, V = 1747.4(3) Å3, Z = 2, Dc = 1.320 Mg m−3, μ = 0.101 mm−1, F(000) = 732, Mr = 694.68, the final R1 = 0.0879 and wR2 = 0.1872 for 8091 observed reflections with I > 2σ(I). The structural analysis reveals that compound 1·2DMF contains one tetramethyl 5,5′-(terephthaloylbis-(azanediyl))-diisophthalate and two N,N-dimethylformamide solvent molecules. A 3D supramolecular structure of 1·2DMF is constructed by multiply intermolecular C–H···O H-bonds and π–π stacking interactions. In addition, compound 1 exhibits a strong blue fluorescence at 413 nm in the solid state at room temperature.

The binding reaction of betaxolol (BET) with bovine serum albumin (BSA) in aqueous buffer solution has been investigated using isothermal titration calorimetry (ITC) and circular dichroism (CD) spectroscopy. The thermodynamic results indicate that there were two classes of binding sites on each BSA molecule for BET molecules. The changes of standard Gibbs free energy (ΔG1° and ΔG2°) are almost the same when the drug molecules bind to the first and the second classes of sites. However, the changes of standard enthalpy (ΔH1° and ΔH2°) are −38.35 ± 0.50 and 18.06 ± 0.03 kJ mol−1, respectively. The first class of binding is an enthalpy driven process while the second class of binding is an entropy driven one. The results of spectroscopic experiment were applied to investigate the structure of the BSA–BET complex and to understand the thermodynamic data.

The inclusion process of 2′-hydroxyl-5′-methoxyacetophone (Hma) with β-cyclodextrin (β-CD), as well as their other seven possible interaction types, was investigated theoretically. The data suggest that: (1) the inclusion complex formed by Hma entering into the cavity of β-CD from its wide side (the secondary hydroxyl group side) is more stable than that from its narrow side (the primary hydroxyl group side); (2) the formation of the inclusion complex is predicted to be an enthalpy-driven process in gas phase and an enthalpy–entropy co-driven process in aqueous solution, which is in accord with the experimental results; (3) other different interaction types between Hma and β-CD should be also possibly found experimentally due to their negative binding energy (ΔE) though their distributions differ greatly. At last, comparative study of the interactions of β-CD with Hma and its two isomers, paeonol (Pae) and acetovanillone (Ace), are investigated and their obvious differences in binding energy and enthalpy change suggest that the β-CD could identify the three isomers.

Thermodynamic parameters for formation of the inclusion complexes of α-, β- and γ-cyclodextrin (α-, β- and γ-CD) with ibuprofen (BF) in Tris-HCl buffer solutions (pH=7.0) have been determined by isothermal titration calorimetry (ITC) with nanowatt sensitivity, and the inclusion structures have been investigated by using 1H-NMR spectra at 298.15 K. A theoretical study on the inclusion processes between BF and CDs has been performed with the B3LYP/6-31G*//PM3 method in order to investigate the formation mechanism of the inclusion complexes. An analysis of the thermodynamic data indicates that the stoichiometries of α-, β- and γ-CD with BF are all 1:1 and formation of the inclusion complexes α-CD⋅BF and β-CD⋅BF are driven by enthalpy and entropy, whereas formation of γ-CD⋅BF is an entropy driven process. The 1H-NMR spectra provide clear evidence for the inclusion phenomenon, and show that the isobutyl group and aromatic ring of the guest molecule are trapped inside the cavity of the CDs. Theoretical calculations suggest that the complex formed by the BF molecule entering into the cavity of the CD molecule from the wide side is more stable than that from the narrow side.