Synthesis Of Cs Research Articles

Organocatalytic Synthesis of (Hetero)arylidene Malononitriles Using a More Sustainable, Greener, and Scalable Strategy.

The establishment of a green and sustainable Knoevenagel condensation reaction in organic chemistry is still crucial. This work aimed to provide a newly developed metal-free and halogen-free catalytic methodology for the synthesis of CS and (hetero-) arylidene malononitriles in the laboratory and industrial scale. The Knoevenagel condensation reaction of various carbonyl groups with malononitrile was investigated in ethanol, an ecofriendly medium, in the presence of seven nitrogen-based organocatalysts. A comparative study was conducted using two as-obtained and four commercially available nitrogen-based organocatalysts in Knoevenagel condensation reactions. The synthesis of CS gas (2-chlorobenzylidene malononitrile) using a closed catalytic system was optimized based on their efficiency and greener approach. The conversion of 100% and excellent yields were obtained in a short time. The products could be crystallized directly from the reaction mixture. After separating pure products, the residue solution was employed directly in the next run without any concentration, activation, purification, or separation. Furthermore, the synthesis of 2-chlorobenzylidenemahmonitrile (CS) was carried out on a large scale using imidazole as a selected nitrogen-based catalyst, afforded crystalline products with 95 ± 2% yield in five consecutive runs. Energy efficiency, cost saving, greener conditions, using only 5 mol% of organocatalyst, high recyclability of catalyst, prevention of waste, recycling extractant by a rotary evaporator for non-crystallized products, demonstrated the potential commercial production of CS using imidazole in ethanol as an efficient and highly recyclable catalytic system.

Modified Synthesis of Cs4PbBr6 for Enhanced Purity and Quantum Yield and for Exploring Its Potential as a High Stokes Shift Material for Down‐Conversion in Solar Cells

Energy demands have kept increasing in recent years due to expanding human activity. Silicon solar cells offer an attractive renewable energy source while their external quantum efficiency (EQE) can still be enhanced; one way of doing this is by applying a photon energy downshifting layer. Herein, Cs4PbBr6 is applied as a downshifting layer; the Cs4PbBr6 is synthesized in the form of colloidal nanoparticles, and several modifications are introduced to the synthesis process, resulting in the enhancement of the photoluminescence quantum yield, improving the particle size distribution and reducing the CsBr impurities which appear as a side product during the synthesis of Cs4PbBr6. The application of the produced modified particles in the form of thin films on the top of Si solar cells shows an enhancement of the (EQE) of the solar cells when compared to the unmodified particles.

Green-chemistry synthesis and optical properties of lead-free Cs2AgSbCl6 double perovskite by a mechanochemical method

Cs2AgSbCl6 double perovskite (DP) has been synthesized through many solid-state and solution routes.

Manganese silicate/MoS2 composite material with high adsorption capacity for the selectively removing Cs+ from aqueous solution over a wide pH

The wastewater generated by nuclear power plants contains a large number of radioactive substances, including 134Cs and 137Cs, which pose significant threats to human health and the environment. It is crucial to remove these radioactive substances from the nuclear waste. A significant challenge we encounter is the effective and selective extraction of cesium ions from wastewater. The wastewater is typically rich in competition ions and spans a wide pH range. In this report, we report a novel manganese silicate/MoS2 composite material with high adsorption capacity for selectively removing Cs+ from aqueous solutions with competition ions. Adsorption behaviors of cesium ions were investigated for composite ratio, adsorbent dosage, contact time, pH and competitive cations. Optimal conditions for the adsorption of cesium ions from aqueous solutions were achieved using a composite ratio of manganese silicate to MoS2 at 9:1, an adsorbent concentration of 1.0 g L−1, and a pH of 8 for a duration of 1 h. While the impact of K+ and Na+ is minimal at lower concentrations, it becomes more pronounced with increasing concentrations. The composite material demonstrates effective performance over the pH range of 2.0–12.0. Experimental data fitted with the pseudo-second-order kinetics and the Langmuir isotherm model suggests a single-layer chemical adsorption process, resulting in a remarkable adsorption capacity of 78.99 mg g−1. Microscopic analysis reveals the synergistic effect of manganese silicate and MoS2. The manganese silicate provides efficient active sites for selective Cs+ adsorption, while MoS2 allows the highly dispersed surface for manganese silicate. This work reveals new insights into the design and synthesis of high-performance Cs+ adsorption materials for application in the treatment of nuclear wastewater.

One-step synthesis of all-inorganic high-entropy dual-phase Cs‘B’Br3/Cs‘B’2Br5 perovskite nanocrystals by high-energy ball milling

All-inorganic lead halide perovskite nanocrystals (NCs) have attracted considerable attention in field of optoelectronics due to their excellent properties such as high PLQY, tunable emission spectra in visible light region, and narrow emission peaks. However, problems existing in the research of all-inorganic lead halide perovskite materials are high lead content, low stability, and complex synthesis processes. Those problems need to be solved urgently. Therefore, dual-phase Cs‘B’Br3/Cs‘B’2Br5 perovskite material (Cs(Pb1/5Mn1/5Ni1/5Zn1/5Cd1/5)Br3/Cs(Pb1/5Mn1/5Ni1/5Zn1/5Cd1/5)2Br5) was synthesized by doping the B-site of CsPbBr3 and CsPb2Br5 using high-energy ball milling in this thesis. This dual-phase perovskite material has maximum absorption edge of 540 nm, a band gap width of 2.22 eV, the maximum emission peak at 600 nm with FWHM of 72 nm, PLQY of 24.50%, and an average fluorescence lifetime of 227.87 μs. After 21 days at room temperature, luminescent intensity of NCs increased to 156%, and still retained 109% at 120 days. After treatment at 150 °C, luminescent intensity decreased to 47%. Results show that this high-entropy dual-phase perovskite has great stability in different temperature. This proves that synthesis of high-entropy dual-phase halide perovskite by high-energy ball milling is feasible, and has great significance in solving poor stability and high lead content of all-inorganic lead halide perovskite in the future.

Room-Temperature Solid-State Synthesis of Cs3Cu2I5 Thin Films and Formation Mechanism for Its Unique Local Structure.

Blue-emitting Cs3Cu2I5 has attracted attention owing to its near-unity PL quantum yield and applications in DUV photodetectors and scintillators. Its PL properties originate from the unique local structure around the luminescent center, the [Cu2I5]3- polyhedron iodocuprate anion consisting of the edge-shared CuI3 triangle and the CuI4 tetrahedron dimer, which is isolated by Cs+ ions. We found that solid-state reactions between CsI and CuI occur near room temperature (RT) to form Cs3Cu2I5 and/or CsCu2I3 phases. High-quality thin films of these phases were obtained by the sequential deposition of CuI and CsI by thermal evaporation. We elucidated that the formation of interstitial Cu+ and the antisite of I- at the Cs+ site in the CsI crystal through Cu+ and I- diffusion results in the RT synthesis of Cs3Cu2I5. The unique structure formation of the luminescent center was revealed using a model based on the low packing density of the CsCl-type crystal structure, similar sizes of Cs+ and I- ions, and the high diffusivity of Cu+. The self-aligned patterning of the luminous regions on thin films was demonstrated.

Synthesis of Cs+-Tuned (PEA)2PbI4 Perovskite Thin Films by One-Step Spin Coating

As a candidate material for the next generation photovoltaic and light-emitting devices, organic-inorganic hybrid perovskite materials have attracted extensive attention. In this study, a (PEA)2PbI4 hybrid perovskite film was prepared by a one-step spin-coating method at room temperature. Based on the synthesis of (PEA)2PbI4, the inorganic Cs+ ions were doped in the film to investigate the influence of Cs+ doping on the structure and properties of two-dimensional (2D) perovskite film. The results show that both as-grown (PEA)2PbI4 film and Cs+-doped (PEA)2PbI4 film exhibit the instinct of the layered structure, though excess Cs+ ions doping would make the structure weakened. Through analyzing the optical properties, it is found that, besides the 2D (PEA)2PbI4 phase, a quasi-2D structure with two layers of [PbI6]4−-octahedron forms in Cs+-doped (PEA)2PbI4 perovskite films, which is ascribed to the phase rearrangement of the (PEA)2PbI4 crystal structure under the induction of Cs+ ions.

Solvent Evaporation Induced Large-Scale Synthesis of Cs4PbBr6 and CsPbBr3 Microcrystals: Optical Properties and Backlight Application for LEDs.

The contemporary work focuses on embossing the emissive nature of lead halide perovskite materials, specifically Cs4PbBr6 microcrystal powder prepared via single step bulk recrystallization method followed by the solvent evaporation route from gram to kilogram scale. The X-ray diffraction pattern confirms the formation of phase pure Cs4PbBr6 with a goodness of fit value of 1.51 calculated from Rietveld refinement and the fluorophore powder manifesting an intrinsic band gap of 3.76 eV. The experimental yield of 99.4% indicates the absence of any unreacted precursors. The fabricated flexible, free-standing Cs4PbBr6@PMMA film encompassed better moisture stability without undergoing phase transitions for 400 days. The temperature-dependent photoluminescence spectra denote that 51% of the intensity was retained when cooled back to room temperature after heating it till 180 °C. Moisture studies at two extreme humidity conditions also reveal the appreciable stability of the fluorophore film against moisture. The stability studies with respect to UV irradiation substantiate that the film retained its stability even after exposing it continuously to UV radiation for seven days. The outstanding optical properties of these microcrystals, owing to the higher exciton binding energy, make them a promising candidate as excellent fluorophores for color conversion, backlight, and light-emitting applications. The Cs4PbBr6@PMMA film was employed as the top cover of a commercial blue LED, producing a robust green emission which revealed its possible application as a phosphor material.

Room temperature synthesis and pressure-induced optical properties of lead-free 2D Cs3Bi2I6Cl3 perovskite nanocrystals

High pressure is performed to investigate the optical response and the structure evolution of 2D Cs3Bi2I6Cl3 nanocrystals.

Synthesis and optical properties of Cs4PbBr6 perovskite nanocrystals by the water assisted solid-state reaction (WASSR) method

Herein, we demonstrate the synthesis of green-emitting Cs4PbBr6 perovskite nanocrystals by the WASSR method for the first time.

Microwave-assisted synthesis of new Cs doped ZrV2O7 nanorods with remarkably improved visible-light-driven photocatalytic performance

Herein, a facile and economic method was demonstrated for the synthesis of a novel mixed metal oxides, Cs doped ZrV2O7 in form of nanorods, with a cubic structure by precipitation-hydrothermal assisted microwave processes. Doping monovalent cations such as Cs ions played a crucial role in tuning the particles into rods and decreasing the optical bandgap that improves the photocatalytic activity. On the other hand, microwave treatment increased the bandgap and grain size of samples. The enhanced photocatalytic activity of the ZrV2O7 nanorods also offers the potential applications in ion exchangers and sensors.

Colloidal Synthesis of Shape-Controlled Cs2NaBiX6 (X = Cl, Br) Double Perovskite Nanocrystals: Discrete Optical Transition by Non-Bonding Characters and Energy Transfer to Mn Dopants

As an alternative to lead halide perovskites, various types of lead-free perovskites have been recently studied for optoelectronic materials. This paper reports the synthesis of highly phase-pure C...

Synthesis and Characterization of a Novel Peptide-Grafted Cs and Evaluation of Its Nanoparticles for the Oral Delivery of Insulin, in vitro, and in vivo Study [Retraction

[This retracts the article DOI: 10.2147/IJN.S161240.].

Synthesis, Crystal Structure, and Characterization of a Noncentrosymmetric Sulfate Cs2Ca2(SO4)3

The noncentrosymmetric structure is one prerequisite of a nonlinear optical (NLO) material. Here, a sulfate Cs2Ca2(SO4)3 with a noncentrosymmetric structure was synthesized by high‐temperature solid‐state reaction, and its crystals were grown by spontaneous crystallization. Single‐crystal X‐ray diffraction indicates that Cs2Ca2(SO4)3 features a three‐dimensional framework constituted by corner‐sharing CaO6 octahedra and SO4 tetrahedra. Optical characterizations suggest that Cs2Ca2(SO4)3 is transparent down to 200 nm and exhibits a moderate second‐order NLO response of about 0.6 × KH2PO4. Electronic band structure calculations were performed to elucidate the optical origin. Furthermore, the title compound has good thermal stability of up to about 1000 K, which is greatly higher than those of NLO sulfates reported recently. This work may shed useful light on the development of new NLO sulfates with high thermal stability.

Hierarchical Cs–Pollucite Nanozeolite Modified with Novel Organosilane as an Excellent Solid Base Catalyst for Claisen–Schmidt Condensation of Benzaldehyde and Acetophenone

Cs–pollucite can be a potential solid base catalyst due to the presence of (Si-O-Al)−Cs+ basic sites. However, it severely suffers from molecular diffusion and pore accessibility problems due to its small micropore opening. Herein, we report the use of new organosilane, viz. dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (TPOAC), as a promising pore-expanding agent to develop the hierarchical structure in nanosized Cs–pollucite. In respect to this, four different amounts of TPOAC were added during the synthesis of hierarchical Cs–pollucite (CP-x, x = 0, 0.3, 1.0, or 2.0, where x is the molar ratio of TPOAC) in order to investigate the effects of TPOAC in the crystallization process of Cs–pollucite. The results show that an addition of TPOAC altered the physico-chemical and morphological properties of hierarchical Cs–pollucite, such as the crystallinity, crystallite size, pore size distribution, surface areas, pore volume, and surface basicity. The prepared solids were also tested in Claisen–Schmidt condensation of benzaldehyde and acetophenone, where 82.2% of the conversion and 100% selectivity to chalcone were achieved by the CP-2.0 catalyst using non-microwave instant heating (200 °C, 100 min). The hierarchical CP-2.0 nanocatalyst also showed better catalytic performance than other homogenous and heterogeneous catalysts and displayed a high catalyst reusability with no significant deterioration in the catalytic performance even after five consecutive reaction runs.

Novel and Innovative Interface as Potential Active Layer in Chem-FET Sensor Devices for the Specific Sensing of Cs.

An innovative novel interface has been designed and developed to be used as a potential active layer in chemically sensitive field-effect transistor (Chem-FET) sensor devices for the specific sensing of Cs+. In this study, the synthesis of a specific Cs+ probe based on calix[4]arene benzocrown ether, its photophysical properties, and its grafting onto a single lipid monolayer (SLM) recently used as an efficient ultrathin organic dielectric in Chem-FETs are reported simultaneously. On the basis of both optical and NMR titration experiments, the probe has shown high selectivity and specificity for Cs+ compared to interfering cations, even if an admixture is used. Additionally, Attenuated Total Reflectance Fourier Transform Infra Red (ATR-FTIR) spectroscopy was successfully used to characterize and prove the efficient grafting of the probe onto a SLM and the formation of the innovative novel sensing layer.

Composition related structural transition between mechanosynthesized CsPbBr3 and CsPb2Br5 perovskites and their optical properties

A facile solvent-free mechanochemical synthesis mechanism of perovskites of Cs–Pb–Br system has been demonstrated in the present study. Inherent structural and microstructural characteristics of CsPbBr3 and CsPb2Br5 perovskites are investigated by analyzing powder XRD patterns using Rietveld refinement analysis and formation of these perovskites has been ascertained. The compositional phase transition between orthorhombic CsPbBr3 and tetragonal CsPb2Br5 perovskites has been explained from the structural point of view. The optically active orthorhombic CsPbBr3 perovskite transforms to optically inactive tetragonal CsPb2Br5 perovskite under flowing water vapour within a short duration and the reverse transformation is noticed when the tetragonal perovskite is heat-treated at elevated temperature. Optical properties of these perovskites corroborate well with structural phase transitions of these compounds. This new approach of structural conversion not only provides a controlled synthesis of the ternary Cs–Pb–Br system but also demonstrates a clear underlying mechanism for the structural instability and associated optical properties.

Metal-free visible-light-promoted thiocyanation/cyclization cascade for the synthesis of thiocyanato-containing isoquinolinediones

A visible-light induced metal-free thiocyanate radical addition/intramolecular cyclization cascade reaction for the synthesis of thiocyanato-containing isoquinolinediones from N-alkyl-N-methacryloylbenzamides is described. The organic dye 9-mesityl-10-methylacridinium perchlorate (Acr+-Mes ClO4−) is used as a photocatalyst, and cheap and readily available ammonium thiocyanate is used to provide thiocyanate radical by single-electron transfer pathway. The reaction completes the synthesis of CS and CC bonds in one pot with abundant molecular oxygen as the sole sacrificial reagent. The method is easy to implement, and 25 new compounds have been prepared in moderate to good yields under mild conditions. This is the first time that a thiocyanate group has been introduced into isoquinoline-1,3(2H,4H)-diones to construct highly functional drug-like molecules.

Facile synthesis of urchin-like Cs x WO3 particles with improved transparent thermal insulation using bacterial cellulose as a template.

Urchin-like CsxWO3 particles were synthesized using bacterial cellulose (BC) as a template by the hydrothermal method. The effects of the BC addition amount on the morphology, W5+ content and transparent thermal insulation of CsxWO3 were studied. It has been confirmed that abnormal growth of CsxWO3 rods was greatly reduced after introduction of BC into the precursor solution. Moreover, introduction of BC into the precursor solution could significantly improve the transparent thermal insulation properties of the CsxWO3 film. In particular, when the BC amount was appropriate, the prepared CsxWO3 film exhibited better visible transparency, with the visible light transmittance (TVis) more than 60%. In addition, the urchin-like particles could be transformed into small size nanorods after H2 heat-treatment, exhibiting excellent visible light transparency and thermal insulation performance. In particular, it has been proved that the 20BC-HT-CsxWO3 film exhibits excellent thermal insulation performance, and shows broad application prospects in the field of solar heat filters and energy-saving window glass.

A facile synthesis of Cs loaded TiO2 nanotube photoelectrode for the removal of 4-chloroguaiacol

In this study, novel Cesium (Cs) doped TiO2 nanotubes photoelectrode (Cs/TiO2NTs) were synthesized by simple electrochemical anodization method and characterized by several physicochemical techniques. In particular, the photocatalytic (PC), electrocatalytic (EC) and photoelectrocatalytic (PEC) activity of newly synthesized Cs/TiO2NTs electrodes was investigated using 4-Chloroguaiacol (4-CG). The effect of operating parameters like Cs concentration, electrolyte concentration, external current and pH on degradation efficacy was examined. PEC oxidation using Cs/TiO2NTs lead to 92% degradation of 4-CG in 6 h of solar light irradiation under optimized conditions (2.5 mM Cs, 160 mg L−1 Na2SO4, 0.03 A current and pH 3). A comparative assessment between PEC, PC and EC process manifested that PEC process was most efficient than the other two processes and Cs/TiO2NTs exhibited higher PEC activity than bare-TiO2 electrodes in terms of degradation and mineralization of organic pollutant. The generation of OH radicals was found to be highest in PEC when compared to EC and PC process. Possible intermediates/byproducts were identified by GC-MS technique and a corresponding tentative degradation pathway has been proposed. Cytotoxicity study showed that PEC has potential to detoxify 4-CG. Hence, combination of TiO2 electrodes decorated with Cs metal can act as a highly efficient photoelectrode for the degradation of hazardous pollutants.