Incorporating two organic ligands with different functionalities into a titanium-oxo cluster entity simultaneously can endow the material with their respective properties and provide synergistic ...performance enhancement, which is of great significance for enriching the structure and properties of titanium-oxo clusters (TOCs). However, the synthesis of such TOCs is highly challenging. In this work, we successfully synthesized a TBC4A-functionalized TOC, Ti2(TBC4A)2(MeO)2 (Ti2; MeOH = methanol, TBC4A = tert-butylcalix4arene). By adjusting the solvent system, we successfully introduced 1,10-phenanthroline (Phen) and prepared TBC4A and Phen co-protected Ti2(TBC4A)2(Phen)2 (Ti2-Phen). Moreover, when Phen was replaced with bulky 4,7-diphenyl-1,10-phenanthroline (Bphen), Ti2(TBC4A)2(Bphen)2 (Ti2-Bphen), which is isostructural with Ti2-Phen, was obtained, demonstrating the generality of the synthetic method. Remarkably, Ti2-Phen demonstrates good stability and stronger light absorption, as well as superior photoelectric performance compared to Ti2. Density functional theory (DFT) calculations reveal that there exists ligand-to-core charge transfer (LCCT) in Ti2, while an unusual ligand-to-ligand charge transfer (LLCT) is present in Ti2-Phen, accompanied by partial LCCT. Therefore, the superior light absorption and photoelectric properties of Ti2-Phen are attributed to the existence of the unusual LLCT phenomenon. This study not only deeply explores the influence of Phen on the performance of the material but also provides a reference for the preparation of materials with excellent photoelectric performance.
The morphology and porosity of zeolites have an important effect on adsorption and catalytic performance. In the work, simple inorganic salts, i.e., Na salts were used to synthesize MWW zeolite using ...the organic compound 1-Butyl-2,3-dimethyl-1H-imidazol-3-ium hydroxide as a structure-directing agent and the morphology was regulated by the alkali metals. The sample synthesized without Na salts shows a dense hexagon morphology, while different morphologies like ellipsoid, wool ball, and uniform hexagon appear when using NaOH, Na
CO
, and NaHCO
, respectively. Moreover, the impact of Na salts on the induction, nucleation, and the evolution of crystal growth was studied. Different kinds of Na salts have a different impact on the crystalline induction time in the order of NaHCO
(36 h) < Na
CO
(72 h) = NaOH (72 h). Meanwhile, the crystalline mechanism with the cooperation of inorganic salts and the organic SDAs is proposed. NaOH- and Na
CO
-MWW zeolite crystallized with a network of hydrogel via the nonclassical pathway in the system; however, the product is synthesized via a classical route in the NaHCO
environment. This work provides information about MWW zeolite crystallization and modulating diverse morphologies by adjusting the process.
Red phosphorus (RP) has attracted extensive attention as an anodic material for lithium-ion batteries (LIBs) due to its high theoretical specific capacity of 2596 mA h g
− 1
and earth abundance. ...However, the facile and large-scale preparation of the red phosphorus nanomaterials via a solution synthesis remains a challenge. Herein, we develop a simple and facile solution method to prepare red phosphorus nanoparticles (RP NPs). PCl
3
readily reacts with HSiCl
3
in the presence of amines at room temperature to produce amorphous RP NPs with sizes about 100–200 nm in high yields. When used as an anode for rechargeable lithium ion battery, the RP NP electrode exhibits good electrochemical performance with a reversible capacity of 1380 mA h g
− 1
after 100 cycles at a current density of 100 mA g
− 1
, and Coulombic efficiencies reaching almost 100% for each cycle. The study shows that this solution synthesis is a facile and convenient approach for large-scale production of RP NP materials for use in high-performance Li-ion batteries.
Silicon has great potential as an anode material for high-performance lithium-ion batteries (LIBs). This work reports a facile, high-yield, and scalable approach to prepare nanoporous silicon, in ...which commercial magnesium silicide (Mg
2
Si) reacted with the acidic ionic liquid at 100 °C and ambient pressure. The obtained silicon consists of a crystalline, porous structure with a BET surface area of 450 m
2
/g and pore size of 1.27 nm. When coated with the nitrogen-doped carbon layer and applied as LIB anode, the obtained nanoporous silicon-carbon composites exhibit a high initial Coulombic efficiency of 72.9% and possess a specific capacity of 1000 mA h g
−1
at 1 A g
−1
after 100 cycles. This preparation method does not involve high temperature and pressure vessels and can be easily applied for mass production of nanoporous silicon materials for lithium-ion battery or for other applications.
Eu
3+
and Sm
3+
co-doped SrMoO
4
phosphors have been successfully prepared via a simple surfactant-free hydrothermal method. The as-prepared phosphors present dumbbell-like agglomerates and comprise ...of many nanoparticles of 150–300 nm in diameter. Eu
3+
and Sm
3+
co-doped SrMoO
4
phosphors display all the characteristic excitations and emissions of Eu
3+
and Sm
3+
. The introduction of Sm
3+
can generate a strong excitation line at 403 nm, originating from the
6
H
5/2
→
4
K
11/2
transition of Sm
3+
, which significantly broadened the excitation region for matching the near ultraviolet light emitting diodes (∼400 nm). And Sm
3+
ions can transfer the absorbed energy to Eu
3+
ions efficiently, so the intensity of the main emission peak at 614 nm due to
5
D
0
→
7
F
2
transition of Eu
3+
are strengthened by the co-doping of Sm
3+
. The doping concentration of Eu
3+
/Sm
3+
was optimized. In addition, the possible energy transfer mechanism has been investigated and is discussed in detail.
•We reported a simple route to synthesize the Y2O3 HNSs.•A possible formation mechanism of the Y2O3 HNSs was proposed.•The Ln-doped Y2O3 HNSs exhibit characteristic emission with different ...colors.•White-light-emitting phosphor Y2O3:Tm3+, Dy3+ was also successfully synthesized.
A novel, fast and simple method was developed to synthesize the undoped and lanthanide-doped yttrium oxide hollow nanospheres (Y2O3⋅HNSs) with multicolored downconversion emission under mild conditions by employing poly (acrylic acid sodium salt) microspheres (PAAS MSs) as active templates followed by a subsequent calcination process. The structure, morphology, formation process, and fluorescent properties are well investigated using various techniques. The results show that the samples can be well indexed to the pure cubic phase of Y2O3. The possible formation mechanism of the PAAS MSs, PAA-Y precursor, and Y2O3 HNSs are proposed and discussed in detail. Upon ultraviolet excitation, the obtained Y2O3:Ln3+ (Ln=Eu, Dy, Er, Tm) HNSs exhibit strong red, yellow–green, blue, yellow emission, respectively. Moreover, a novel single-phased and near-UV-pumped white-light-emitting phosphor Y2O3:Tm3+, Dy3+ was also successfully fabricated through optimizing the molar ratio among Tm3+ and Dy3+ in the Y2O3 host. This material may find potential applications in field-emission display devices and white ultraviolet light-emitting diodes (UV LEDs). Furthermore, this synthesis route may be of great significance in the preparation of other hollow spherical materials.
Uniform LuF3 products with different morphologies and sizes were prepared through a facile synthesis route in imidazolium ionic liquids.
•OmimPF6 acts not only as a reactant but also as a ...morphology-directing agent was introduced to prepare uniform LuF3 nanocrystals.•Morphology and size-controlled synthesis of rare earth doped LuF3 for the first time, different shapes of the orthorhombic LuF3 nanocrystals were obtained in this research.•The effect of different sizes and morphologies on luminescence properties has also been discussed.•This study provides more alternatives of rare earth fluorides that exhibit strong characteristic emission, and further complements the exploration of Lu-based nanomaterials, which may have unique properties that the Y/Ln-based nanoparticles do not possess and may serve as versatile luminescent phosphors for further application.
High quality lanthanide ions doped LuF3 have been successfully prepared via the solvothermal method and using 1-octyl-3-methylimidazolium hexafluorophosphate (OmimPF6) as fluoride source. In this synthesis procedure, ionic liquids (ILs) OmimPF6 act not only as a reactant but also as a morphology-directing agent. The results indicate that the morphology and size of LuF3:Ln3+ (Ln3+=Eu3+, Tb3+, Dy3+) products can be rationally modified by tuning the synthesis temperature, time and using different kinds of solvents. Moreover, the luminescent properties of the products with different morphologies were systematically studied. The photoluminescence (PL) properties of the as-synthesized samples revealed that Eu3+ doped LuF3 nanocrystals with different morphologies present characteristic transition of Eu3+, and their emission intensities strongly depend on morphology and size. The effect of Eu3+ doping concentration on PL intensity was also investigated.
Nanostructured silicon‐based materials with porous structures have recently been found to be impressive anode materials with high capacity and cycling performance for lithium‐ion batteries. However, ...the current methods of preparing porous silicon have generally been confronted with the requirement for multiple steps and complex synthesis. In the present study, porous silicon with high surface area was prepared by using a high yielding and simple reaction in which commercial magnesium powder readily reacts with HSiCl3 with the help of an amine catalyst under mild conditions. The obtained porous silicon was coated with a nitrogen‐doped carbon layer and used as the anode for lithium‐ion batteries. The porous Si‐carbon nanocomposites exhibited excellent cycling performance with a retained discharge capacity of 1300 mA h g−1 after 200 cycles at 1 A g−1 and a discharge capacity of 750 mA h g−1 at a current density of 2 A g−1 after 250 cycles. Remarkably, the Coulombic efficiency was maintained at nearly 100 % throughout the measurements.
Letting anodes breathe: Porous silicon is prepared by using a simple, high yielding solution reaction. The material exhibits excellent cycling and rate performance when used as an anode for lithium ion batteries.
Carbon materials are attracting increasing attention because they are widely applied in batteries, supercapacitors, catalysis and other fields. In this work, we report a simple one-pot method to ...produce nitrogen-doped carbon materials (NCMs) by reacting N-bromosuccinimide with calcium carbide. The obtained carbon structures are partially graphitic, with significant amount of nitrogen doped into the carbon network. The texture properties of NCMs vary with the preparative temperature. The NCM prepared at 700 °C possessed dual micropores (7 Å and 12 Å) and mesopores with the largest specific surface area of 1436 m2 g−1. It exhibited good charge storing performance when used in a capacitor, with a high specific capacitance of 214.8 F g−1 at the current density of 0.2 A g−1. The capacitance remains 96% after 5000 cycles. This work provides a simple way to synthesize N-containing carbon materials with excellent charge storage properties, which may be used to synthesize other tailored carbon materials with various properties.
Display omitted
•Nitrogen-doped carbon materials (NCMs) are prepared in one pot and high yield from CaC2 and N-bromosuccinimide.•The obtain NCM possesses partially graphitic structure with dual micropores and mesopores and a large specific surface area.•The texture properties of NCMs vary with the preparative temperature.•The obtained NCMs exhibit excellent charge storage properties.
Extra‐large‐pore zeolites have great application potential in various industrial fields, such as oil refinery, fine chemicals and biomass processing. Herein, we report the synthesis of an ...extra‐large‐pore germanosilicate zeolite (named NUD‐13) by using an easily obtained aromatic organic cation 1,2‐dimethyl‐3‐propyl‐benzimidazolium as organic structure‐directing agents. NUD‐13 possesses a rare 15‐member ring extra‐large‐pore channel intersecting with two elliptical 12‐member ring channels, which is isostructural to germanosilicate zeolite GeZA synthesized by using triphenylsulfonium. The germanium in NUD‐13 can be partially substituted by acid treatment to obtain stable high silica zeolite. In addition, aluminium is added into the framework of NUD‐13 during the post‐synthesis treatment process, which provides a foundation for catalytic application.
Extra‐large‐pore germanosilicate zeolite NUD‐13 is synthesized by using an easily obtained 1,2‐dimethyl‐3‐propyl‐benzimidazolium as organic structure‐directing agents, which possesses a rare 15×12×12‐ring pore system. The germanium in NUD‐13 can be partially substituted by post‐synthetic modifications to obtain stable high silica and acidic aluminosilicate zeolites.
PDF
