Qiaoyan Hao

Facile synthesis and characterization of CuInS2 nanocrystals with different structures and shapes

CuInS2 nanocrystals were synthesized by one-pot thermolysis of a mixture solution of metal chlorides, 1-dodecanethiol (DT) and oleic acid in noncoordinating solvent 1-octadecene. Interestingly, in this synthesis, different structures and shapes were obtained by simply varying the dosage of DT. At a low dosage of DT, wurtzite nanoplates formed in the initial reaction stage and then they further grew to nanoplates with wurtzite–zincblende polytypism as the reaction proceeded. On the contrary, a high dosage of DT produced zincblende nanoparticles. The formation processes of nanoplates and nanoparticles were studied and a growth mechanism was proposed. Our research will aid in solution-synthesis of ternary chalcogenide nanocrystals and the development of their optoelectronic devices.

Preparation of interlayer surface tailored protonated double-layered perovskite H2CaTa2O7 with n-alcohols, and their photocatalytic activity

N-alkyl chains have been successfully grafted into the interlayer space of a Ruddlesden–Popper-type double-layered peroviskite, H2CaTa2O7, via a hydrolysis–esterification process. During the chemical graft process, the parent layered structure is well preserved with magnifying the tailored c lattice parameter. IR and solid-state 13C CP/MAS NMR spectra indicated that oxyalkyl chains were successfully introduced. Thermogravimetric curves of the products exhibit the amount of n-alkoxyl groups per perovskite unit [CaTa2O7] is approximated to 1. A linear relationship with a slope of 0.478 nm per carbon atom is observed between the c lattice parameter and the number of carbon atoms in the n-alkyl chains, which illustrates that the n-alkyl chains form bilayers with a tilt angle of 70°. The photocatalytic activities of these products are also discussed. The 1-octadecanol derivative of H2CaTa2O7 is found to serve as an excellent catalyst for the catalytic reduction of rhodamine B (RhB) and methyl orange (MO), which is set as a novel example of an application of this tailored n-propoxy derivative of H2CaTa2O7.

Facile synthesis of AgInS2 hierarchical flowerlike nanoarchitectures composed of ultrathin nanowires

In this work, AgInS(2) hierarchical flowerlike nanoarchitectures, which are composed of ultrathin nanowires, were synthesized by thermolysis of a mixed solution of AgNO(3), InCl(3)·4H(2)O and n-dodecanethiol at elevated temperature. The average diameter and length of the nanowires composing the nanoarchitectures can reach 5 nm and ∼300 nm, respectively. We investigated the growth process of the nanoarchitectures and the effects of reaction parameters by XRD, SEM and TEM. In particular, the use of InCl(3)·4H(2)O played a decisive role in the synthesis of the nanoarchitectures. Moreover, it was found that polyhedra formed in the initial reaction time, and then the nanowires grew on the facets of these polyhedra, which resulted in the nanoarchitectures. The reaction temperature and the concentration of metal salts could influence the size of the nanowires.

D-Glucopyranose-modified compound of Ruddlesden–Popper phases H2CaTa2O7: characterization and intercalation with Ag

D-Glucopyranose rings have been successfully coordinated onto the interlayer surface of a Ruddlesden–Popper-type layered perovskite, H2CaTa2O7, by a reaction with the precursor of n-decoxyl derivative of H2CaTa2O7. The interlayer distance of D-glucopyranose derivative of H2CaTa2O7 was decreased to 19.135(5) A compared to 35.026(0) A for n-decoxyl derivative of H2CaTa2O7. IR and solid-state 13C CP/MAS NMR spectra indicated that the oxyalkyl chains of the precursor were replaced by glucopyranose rings. To extend inorganic–organic hybrids, the H2CaTa2O7 modified was further treated with [Ag(NH3)2]+ solution. Ag nanoparticles are deposited on the interlayer of H2CaTa2O7, and the interlayer distance of the samples is changed into 10.816(6) A. The as-prepared nanohybrids (Ag/H2CaTa2O7) exhibit an excellent catalytic property for the catalytic reduction of both rhodamine B (RhB) and 4-nitrophenol (4-NP) by NaBH4 aqueous solution; therefore, it is a practical and efficient nanocatalyst.

A facile synthesis of highly porous CdSnO3 nanoparticles and their enhanced performance in lithium-ion batteries

CdSnO3 materials have been extensively studied as gas-sensing materials. However, there are few reports on the synthesis and use of porous CdSnO3 nanostructures for energy storage. Herein, we report highly porous CdSnO3 nanoparticles prepared using citric acid with sizes in the range of ∼7.8 nm to 28.7 nm and the application of these nanoparticles as an anode material for rechargeable Li-ion batteries (LIBs). Electrochemical measurements showed that the highly porous CdSnO3 nanoparticles delivered a high reversible capacity of ∼515 mA h g−1 for up to 40 cycles at a current rate of 70 mA g−1. Even at a high rate of 150 mA g−1, the porous CdSnO3 could still deliver a capacity of 506 mA h g−1. It is observed that the electrochemical performance of the highly porous CdSnO3 nanoparticles is much better than that (∼370 mA h g−1 for up to 40 cycles) of a counterpart obtained without citric acid, which also demonstrates the capacity enhancement and high rate capacity.

A FeSe-based superconductor (C 2 H 8 N 2 ) x FeSe with only ethylenediamine intercalated

A new FeSe-based superconductor (C2H8N2)x FeSe with ethylenediamine intercalated into FeSe was successfully synthesized by the solvothermal method, which is the first superconducting instance by metal-free organic molecule intercalation. Elemental analysis and TG-IR-GC/MS data reveal that the ethylenediamine molecules in the interlayer space are separate and intact. The X-ray diffraction (XRD) pattern indicates that the intercalation compound is an orthorhombic lattice rather than a tetragonal lattice applying to almost all the previous FeSe-based superconductors at room temperature. The magnetism measurements display a sharp superconducting transition at ∼10 K which is assigned to (C2H8N2)xFeSe, and a tiny drop in susceptibility at ∼30 K.摘要本文采用水热法成功合成了一种新型铁硒基超导体(C2H8N2)xFeSe, FeSe层间只有乙二胺分子而不包含其他任何金属. 碳氢氮元素分析和热重-红外-质谱联合分析的数据都表明层间的乙二胺分子是完整而且独立的. X射线衍射图指出插层化合物是一个正交格子, 而以往铁硒基超导体在常温下几乎都是四方格子. 磁性测量的数据显示产物在10 K左右有一个大的超导转变, 可归结于插层产物(C2H8N2)xFeSe. 此外, 在30 K处也观察到一个很小的超导转变, 这可能是杂质引起的.

Preparation of ultrathin perovskite nanosheets by the exfoliation of H2CaTa2O7 for high-performance lead removal from water

Intercalation and delamination of two-dimensional solids are effective steps for exploiting their unique properties. Herein, the chemical exfoliation of the n-alcohol derivative of H2CaTa2O7 results in a colloidal suspension of monolayer nanosheets. Microscopic observation confirms the delamination of the parent perovskite. The thickness of the nanosheet obtained is 1.2 ± 0.1 nm. The dimensionally tailored H2CaTa2O7 nanosheets exhibit exceptional uptake of 300 mg g−1 Pb(II) ions at pH 5.0, and adsorption equilibrium is achieved in a short time span of 30 seconds. Experimental studies demonstrate that the treatment capacity for Pb(II) ions in simulated drinking water is 1.67 × 105 kg water per kg adsorbent. Desorption of Pb(II) ions is efficiently realized using 1 M HCl, which greatly reduces the cost associated with the regeneration. The large surface area of the ultrathin nanosheets and their nonporous structure facilitate the uptake of Pb(II) ions.

Synthesis and structure of a new layered oxyfluoride Sr{sub 2}ScO{sub 3}F with photocatalytic property

Highlights: • A new oxyfluoride compound Sr{sub 2}ScO{sub 3}F was prepared by a solid state route. • The structure of this compound was determined by GSAS program based on XRD data. • The photocatalytic property was investigated under UV irradiation. - Abstract: A new Ruddlesden–Popper type scandium oxyfluoride, Sr{sub 2}ScO{sub 3}F, was synthesized by a conventional solid state reaction route. The detailed structure of Sr{sub 2}ScO{sub 3}F was investigated using X-ray diffraction (XRD) and selected area electron diffraction (SAED). The disorder distribution pattern of fluorine anions was determined by the {sup 19}F nuclear magnetic resonance (NMR) spectrum. The compound crystallizes in a K{sub 2}NiF{sub 4}-type tetragonal structure (space group I4/mmm) with O/F anions disordered over the apical sites of the perovskite-type Sc(O,F){sub 6} octahedron layers interleaved with strontium cations. Ultraviolet–visible (UV–vis) diffuse reflection spectrum of the prepared Sr{sub 2}ScO{sub 3}F indicates that it has an absorption in the UV–vis region. The photocatalytic activity of Sr{sub 2}ScO{sub 3}F was further investigated, showing an effective photodegradation of Rhodamine-B (RB) within 2 h under UV light irradiation.