A distinct hollow spindle-like CdIn2S4 photocatalyst for high-efficiency tetracycline removal

Due to the massive release of antibiotics into the environment, it is of great emergency to find an effective approach to deal with antibiotic-containing wastewater. Photocatalytic technology, benefiting from its low cost and high efficiency, is deemed to be an appealing strategy. Photocatalytic-induced production of reactive oxygen species (ROS) is a promising but challenging prospect in water purification and environmental remediation. Herein, we fabricated a spindle-like hollow CdIn₂S₄ (HCIS) photocatalytic system for high-efficiency tetracycline removal. Targeting MIL-88A (Fe) as a template, the obtained CdIn₂S₄ photocatalysts reserved intrinsic spindle-like morphology. Compared with Bulk CdIn₂S₄ (BCIS), this unique hollow structure enhanced light absorption capacity and boosted carriers separation. As a result, the photodegradation efficiency reached over 94.5% within 40 min under visible light illumination. The degradation rate constant was four times higher than that of pristine CdIn₂S₄. We believe this work will endow some lights for the design of hollow catalysts in other environmental applications.     

Reciprocal system 3Tl2S + Bi2Se3 ↔ 3Tl2Se + Bi2S3

The reciprocal system 3Tl₂S + Bi₂Se₃ ? 3Tl₂Se + Bi₂S₃ has been investigated by DTA, X-ray powder diffraction analysis, and emf measurements. Some polythermal sections and the isothermal section at 500 K of the phase diagram and the projection of the liquidus surface of this system have been constructed, and the types and coordinates of the invariant and univariant equilibria have been determined. The existence of wide regions of quaternary solid solutions based on the binary compounds Tl₂S, Tl₂Se, Bi₂S₃, and Bi₂Se₃, and solid solutions between the temary compounds TlBiS₂ and TlBiSe₂ have been established.     

A new perovskite-type compound: Ca4Fe2Ti2O11

A new perovskite-related oxide with a composition Ca₄Fe₂Ti₂O₁₁ has been found in the Ca₂Fe₂O₅-Ca TiO₃ system. Synthesis and characterization by X-ray diffraction and electron microscopy are reported. A model based on a stacking sequence of … OOOTOOOT′ … along theb axis of this material, corresponding to the structure of a compound withn = 4 in theA_nM_nO_3n−1 series, is proposed.     

Synthesis and structure determination of the new Sm2Ti2O5S2 compound

Sm₂Ti₂O₅S₂ was obtained in an attempt to prepare an oxysulfide of samarium and titanium in a way similar to the obtention of the quaternary Sm₃NbO₄Se₃ compound. The structure was determined by single-crystal X-ray diffraction. The following crystal data were obtained: M_r = 540.6 g mol⁻¹, tetragonal symmetry with unit cell parameters a = 3.819(1) A, c = 22.964(5) A, space group I4/mmm (139). Refinement for 127 unique reflections with I > 3σ(1), and 11 variables, converged to the reliability factor R = 1.77 %. The structure can be described as a stacking, along the c-direction, of [Sm₂S₂] slabs of a rock-salt type (two-atom-thick-layers) separated by a 2D network of corner-sharing octahedra [= Ti₂O₅] of a ReO₃ structure type.     

Darstellung und Kristallstruktur der Dialkalimetalltrichalkogenide Rb2S3, Rb2Se3, Cs2S3 und Cs2Se3

Preparation and Crystal Structure of the Dialkali Metal Trichalcogenides Rb₂S₃, Rb₂Se₃, Cs₂S₃, and Cs₂Se₃ Crystalline products were obtained by the reaction of the pure alkali metals with the chalcogens in the molar ratio 2:3 in liquid ammonia at pressures up to 3000 bar and temperatures around 600 K. The substances crystallize in the K₂S₃ type structure (space group Cmc2₁(NO. 36)). Unit cell constants see ?Inhaltsübersicht”?. The characteristic feature of this structure are bent polyanions X₃^2?:(X = S,Se). The new described compounds are compared with the other known alkali metal trichalcogenides.     

Photocatalytic Dye Methyl Orange Decomposition on Ternary Sulfide （CdIn2S4） under Visible-light

A novel and efficient photocatalyst, CdIn2S4, was simply prepared by a programmed temperature hydrothermal method. The product had a nanometer size （10-15 nm） and strong absorption in the range of 200 to 580 nm, and it exhibited visible-light photocatalytic activity to decompose dye methyl orange in aqueous system.     

具有分级纳米结构的In2S3/CdIn2S4在可见光下催化苯甲胺的氧化偶联反应

采用以太阳光为能源、半导体材料为催化剂的催化体系将胺类化合物转化为相应的亚胺类化合物的方法是一种理想的有机合成手段.为了探索这类反应更温和的反应条件及更清晰的反应机理,本工作以NH₂-MIL-68（In）和硫脲为前驱体制备了In₂S₃分级纳米管,并进一步采用热离子交换的方法制备了In₂S₃/CdIn₂S₄纳米管复合材料.采用粉末X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、高分辨透射电子显微镜（HRTEM）、紫外-可见漫反射光谱（UV-vis DRS）、荧光光谱（PL）和电化学阻抗谱（EIS）等分析手段对催化剂的结构、形貌、光电性质等进行了表征.实验结果显示,In₂S₃和CdIn₂S₄间有效异质结降低了In₂S₃/CdIn₂S₄复合材料的光生载流子的复合效率,使In₂S₃/CdIn₂S₄具有较高的催化活性.催化剂的活性测试实验结果证明,In₂S₃和CdIn₂S₄间有效异质结和分级结构间的协同作用使In₂S₃/CdIn₂S₄纳米复合材料可作为一种有效的光催化剂催化氧化苯甲胺的偶联反应.活性物种捕获实验证明该反应是由光生空穴（h⁺）引发的.此外,此研究发现苯甲胺的氧化偶联反应同时可以在氧气或氮气条件下发生,打破了该反应必须要有氧气参与的束缚,拓展了苯甲胺氧化偶联反应的适用范围.循环实验结果显示,催化剂可循环使用五次,证明该催化剂具有较好的稳定性.     

Structures and physical properties of new semiconducting polyselenides Ba2CudeltaAg4-deltaSe5 with unprecedented linear Se(3)4- units

The title compounds were prepared from the elements in evacuated silica tubes at 650 degrees C, followed by slow cooling. Ba2Ag4Se5 forms a new structure type, space group C2/m, with a=16.189(2) A, b=4.5528(6) A, c=9.2500(1) A, beta=124.572(3) degrees, and V=561.4(1) A3 (Z=2). A maximum of 44% of the Ag atoms may be replaced with Cu atoms without changing the structure type. The crystal structure is composed of Ag4Se(5)4- layers, interconnected via the Ba2+ cations. The Ag atoms show irregular [3+1] coordination by the Se atoms, and the Ba atoms are located in capped square antiprisms formed by Se atoms. Most intriguing is the unprecedented occurrence of linear Se(3)4- units. According to the formulation (Ba2+)2(Ag+)4Se(3)4-(Se2-)2, this selenide is electron-precise with eight positive charges equalizing the eight negative charges. Electronic structure calculations indicated the presence of a band gap, as was experimentally confirmed: the electrical conductivity measurement revealed a gap of 0.6 eV for Ba2CuAg3Se5.     

Hydrothermal Synthesis of CdIn2S4 and Photocatalytic Degradation of Methyl Orange under Visible-light Irradiation

CdIn2S4 microspheres were synthesized by a facile hydrothermal method with the temperature ranging from 120 to 200 ℃. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, nitrogen sorption analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy were used to characterize the products. It was found that the crystallographic structure and optical property of the products synthesized at different temperature were almost the same. The SBET of CdIn2S4 products decreased when the synthesized temperature increased, and the largest SBET was 33.16m2g-1 (120 ℃ sample). The degradation of methyl orange (MO) under the visible-light irradiation had been used as a probe reaction to investigate the photocatalytic activity of the as-prepared CdIn2S4, which showed that the CdIn2S4 sample synthesized at 120 ℃ presented the best photocatalytic activity for MO degradation.     

77Se NMR spectra of Se7 and Se5S2 prepared from titanocene pentaselenide; Evidence for pseudorotation

The natural abundance ⁷⁷Se NMR spectra of Se₇ (singlet at 996 ppm vs Me₂Se) and of Se₅S₂ (singlets at 976, 1023 and 1085 ppm) show that these puckered seven-membered ring molecules undergo pseudorotation at 20°C in CS₂ solution. This internal puckering motion makes all atoms of Se₇ equivalent on the NMR time scale, and results in only three sets of non-equivalent Se atoms in Se₅S₂. The chemical shift of seven-membered Se-containing ring molecules is much larger than that of comparable six- or eight-membered homo- or heterocycles, reflecting the unique bonding situation.     

Carbon Quantum Dots Bridged TiO2/CdIn2S4 toward Photocatalytic Upgrading of Polycyclic Aromatic Hydrocarbons to Benzaldehyde

Conversion of hazardous compounds to value-added chemicals using clean energy possesses massive industrial interest. This applies especially to the hazardous compounds that are frequently released in daily life. In this work, a S-scheme photocatalyst is optimized by rational loading of carbon quantum dots (CQDs) during the synthetic process. As a bridge, the presence of CQDs between TiO₂ and CdIn₂S₄ improves the electron extraction from TiO₂ and supports the charge transport in S-scheme. Thanks to this, the TiO₂/CQDs/CdIn₂S₄ presents outstanding photoactivity in converting the polycyclic aromatic hydrocarbons (PAHs) released by cigarette to value-added benzaldehyde. The optimized photocatalyst performs 87.79% conversion rate and 72.76% selectivity in 1 h reaction under a simulated solar source, as confirmed by FT-IR and GC-MS. A combination of experiments and theoretical calculations are conducted to demonstrate the role of CQDs in TiO₂/CQDs/CdIn₂S₄ toward photocatalysis.     

Die Kristallstruktur von K2S3 und K2Se3

The Crystal Structure of K₂S₃ and K₂Se₃ Well formed crystals of K₂S₃ and K₂Se₃ were obtained by reaction of the elements in liquid ammonia at 500 bar and 150°C. The substances are both orthorhombic, space group Cmc2₁. Cell constants are: The structure contains S₃^2?(Se₃^2?) polyanions, with S? S? S(Se? Se? Se) angles of 105.4(102.5)°. The S? S(Se? Se) distance is 2.083(2.383) Å.     

Na2B2Se7, K2B2S7 und K2B2Se7: Drei Perchalkogenoborate mit neuem polymeren Anionengerüst

Na₂B₂Se₇, K₂B₂S₇, and K₂B₂Se₇: Three Perchalcogenoborates with a Novel Polymeric Anion Network Na₂B₂Se₇ (I 2/a; a = 11.863(4) Å, b = 6.703(2) Å, c = 13.811(6) Å, β = 109.41(2)°; Z = 4), K₂B₂S₇ (I 2/a; a = 11.660(2) Å, β = 6.827(1) Å, c = 12.992(3) Å, β = 106.78(3)°; Z = 4), and K₂B₂Se₇ (I 2/a; a = 12.092(4) Å, b = 7.054(2) Å, c = 13.991(5) Å, β = 107.79(3)°; Z = 4) were prepared by reaction of stoichiometric amounts of sodium selenide (potassium sulfide) with boron and sulfur or of potassium selenide and boron diselenide, respectively, at 600°C with subsequent annealing. The crystal structures consist of polymeric anion chains of composition ([B₂S₇]^2?)_n or ([B₂Se₇]^2?)_n formed by spirocyclically connected five-membered B₂S₃ (B₂Se₃) rings and six-membered B₂S₄ (B₂Se₄) rings. The nine-coordinate alkaline metal cations are situated in between.     

A new semiconducting quaternary mixed halogenide: pentathallium dimercury pentabromide tetraiodide,Tl5Hg2Br5I4

A novel quaternary mixed halogenide, Tl₅Hg₂Br₅I₄, was synthesized by fusion of thallium bromide and mercury iodide in a 5:2 molar ratio. The crystal structure of Tl₅Hg₂Br₅I₄ represents a new series of composite structures described by the general formula nTlBr*mTl₂[HgBr₂I₂]; in this case, n = 4 and m = 8. Electronic structure calculations indicate that the title compound is a semiconductor.     

A pseudopotential study of the hydrogen bond in H2O·H2S,H2S·H2S and H2O·H2Se systems

Intermolecular potential energy curves for the hydrogen bonded systems H₂O·H₂S, H₂O·H₂Se and H₂S·H₂S were calculated with nonempirical pseudopotentials using optimized-in-molecules basis sets augmented by polarization functions. The H₂O·H₂O interaction energy curve has been also considered as a test case. The present results for H₂O·H₂S and H₂S·H₂S indicate much weaker intermolecular interactions than those found in previous ab initio calculations. The H₂O·H₂Se interaction was found to be quite similar to H₂O·H₂S.This work was partly supported by the Polish Academy of Sciences within the Project PAN-09, 7.1.1.1On leave from Quantum Chemistry Laboratory, Dept. of Chemistry, University of Warsaw, Pasteura 1, 02-093. Warsaw, Poland