Solution-phase Route Research Articles

Diselenide Dianion’s Dual Powers: PdSe2Polymorph Control and Pd3Se10Superatomic Crystal Creation

There is a diverse family of palladium selenide compounds, including semiconducting orthorhombic PdSe2 (O-PdSe2) and monoclinic PdSe2 (M-PdSe2), which are unusual among transition-metal dichalcogenides as they are composed of diselenide dianions Se22–. Thus far, the solution syntheses of materials with Se–Se bonds typically require the in situ reduction of Se precursors. Here, we explore the use of electrochemically precise reactions between Na2Se2 and a Pd2+ source, Na2PdCl4, as a solution-phase route to selectively form different PdSe2 polymorphs in the absence of surfactants. By altering the reactant molar ratios and time, we map out a synthetic phase space diagram that shows how to create a wide variety of palladium selenide phases. With increasing Se22–/Pd2+ molar ratios, regions are identified where Pd17Se15, M-PdSe2, and O-PdSe2 exist as the dominant or exclusive thermodynamic product. Additionally, we discover Pd3Se10, a superatomic crystal composed of Pd6Se20 cube-shaped clusters held together by van der Waals forces, which forms as a kinetic product under short reaction times. In total, the use of the diselenide dianion precursor allows for the selective solution-phase synthesis of M-PdSe2 or O-PdSe2, as well as the discovery of a previously unreported palladium selenide phase.

Synthesis of [1-8-NαC]-zanriorb A1, alanine-containing analogues, and their cytotoxic and anti-inflammatory activity.

The synthesis of the orbitide[1-8-NαC]-zanriorb A1, isolated from the medicinal plant Zanthoxylum riedelianum, was investigated by solution-phase macrocyclization of a linear peptide and on-resin solid-phase macrocyclization with an acylsulfonamide safety-catch linker. The solution-phase route produced a mixture of proline rotamers, and the main component was assigned as the trans, cis rotamer, identical to the natural product. The on-resin cyclization was less successful, producing mainly a linear peptide, and minor cyclic products as rotameric mixtures. Although the natural product was reported to be significantly cytotoxic against Jurkat leukemia T cells, our synthetic peptides were inactive, suggesting the presence of other rotamers or impurities in the naturally isolated material. Additional analogues of zanriorb A1 were synthesized in which proline and glycine residues were replaced with alanine. While these analogues were not cytotoxic, several of them inhibited the production of nitric oxide in lipopolysaccharide (LPS)-stimulated macrophages. The most active compound, cyclic[Ala5,6,8 ]-zanriorb A1 had an IC50 of 22 μM and was more potent compared with the standard NG-monomethyl-l-arginine acetate (L-NMMA) with an IC50 of 98 μM, indicating their strong anti-inflammatory potential.

Achieving high Li-storage properties of iron oxalate by designing distinct morphologies

Designed morphology for structure-function relationship in the electrode materials is always heat topics in electrochemical energy storage. Herein, we reported that the facile, scalable liquid phase precipitation achieves the construct of urchin-like iron oxalate of three-dimensional structure at room temperature. Farther exploring found that present surfactant (CTAB) could occupy uncleating active sites for iron oxalate, thus generating one-dimensional rod-shape iron oxalate. The electrochemical measurements for iron oxalate urchins and rods exhibit high Li-storage performances: the initial discharge capacities of 1677 and 1746 mAh g−1 and even stable capacities of 747 and 1024 mAh g−1 after 200 cycles, respectively. This work provides a new promising way for designing three-dimensional structure of iron oxalates by a simple solution-phase route.

Facile One-Step Solution-Phase Route to Synthesize Hollow Nanoporous CuxO Microcages on 3D Copper Foam for Superior Li Storage

In this report, we develop a simple and effective one-step solution-phase route to in situ synthesize hollow nanoporous CuxO microcages on 3D copper foam. When used as an anode for lithium-ion batt...

Peptide-targeted dendrimeric prodrugs of 5-aminolevulinic acid: A novel approach towards enhanced accumulation of protoporphyrin IX for photodynamic therapy

Photodynamic therapy (PDT) is a promising approach for the targeted treatment of cancer and various other human disorders. An effective, clinically approved approach in PDT involves the administration of 5-aminolevulinic acid (ALA) to generate elevated levels of the natural photosensitiser protoporphyrin IX (PpIX). The development of prodrugs of ALA is of considerable interest as a means to enhance the efficiency and cell selectivity of PpIX accumulation for PDT applications. In this work a novel peptide-targeted dendrimeric prodrug of 5-aminolevulinic acid (ALA) 13 was synthesised which displays nine copies of ALA on a core structure that is linked to a homing peptide for targeted delivery to a specific cancer cell type. The synthesis was accomplished effectively via a flexible, modular solid phase and solution phase route, using a combination of solid phase peptide synthesis and copper-catalysed azide-alkyne cycloaddition chemistry. The prodrug system shows a sustained and enhanced production of protoporphyrin IX (PpIX) in the MDA-MB-231 cell line that over-expresses the epidernal growth factor receptor (EGFR+) in comparison to equimolar ALA and the corresponding non-targeted ALA dendrimer (nine copies of ALA). This study provides a proof of concept for the development of a new generation of prodrugs for ALA-based photodynamic therapy that can deliver an enhanced ALA payload to specific tissue types.

Air stable and highly efficient Bi3+-doped Cs2SnCl6 for blue light-emitting diodes.

Cs2SnCl6 perovskite has recently attracted attention as a promising optoelectronic material owing to its better stability and reduced toxicity than its lead counterparts. However, its luminescence performance hardly satisfies the requirements. Hence, a series of Bi3+-doped Cs2SnCl6 (Cs2SnCl6:Bi3+) with enhanced luminescence were synthesized by a solution-phase route. The results show that the initial concentration of Sn2+ can adjust the nucleation density and the quality of the crystal nucleus growth, which will affect the Bi3+ doping amount, crystal morphology, and photophysical properties of Cs2SnCl6:Bi3+. Cs2SnCl6:Bi3+ shows excellent stability in the atmosphere with a photoluminescence (PL) of around 456 nm and a photoluminescence quantum yield (PLQY) of 31%. The luminescence performance results from [BiSn4+3+ + VCl] defects caused by the Bi3+ doping. The blue LED based on the Cs2SnCl6:Bi3+ phosphor exhibits a long life of about 120 h and a Commission Internationale de L'Eclairage (CIE) color coordinates of (0.14, 0.11). This work demonstrates a strategy for Bi-doped perovskites with good stability. This investigation will facilitate the development of Cs2SnCl6:Bi3+ for blue LED applications.

“Broken-hearted” carbon bowl via electron shuttle reaction: energetics and electron coupling

Unprecedented one-step C Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> C bond cleavage leading to opening of the buckybowl (π-bowl), that could provide access to carbon-rich structures with previously inaccessible topologies, is reported; highlighting the possibility to implement drastically different synthetic routes to π-bowls in contrast to conventional ones applied for polycyclic aromatic hydrocarbons. Through theoretical modeling, we evaluated the mechanistic pathways feasible for π-bowl planarization and factors that could affect such a transformation including strain and released energies. Through employment of Marcus theory, optical spectroscopy, and crystallographic analysis, we estimated the possibility of charge transfer and electron coupling between “open” corannulene and a strong electron acceptor such as 7,7,8,8-tetracyanoquinodimethane. Alternative to a one-pot solid-state corannulene “unzipping” route, we reported a nine-step solution-based approach for preparation of novel planar “open” corannulene-based derivatives in which electronic structures and photophysical profiles were estimated through the energies and isosurfaces of the frontier natural transition orbitals.

Dedicated to a peptide chemist of few words and immense impact: Louis A. Carpino

Dedicated to a peptide chemist of few words and immense impact: Louis A. Carpino

Solution-Liquid-Solid Growth and Catalytic Applications of Silica Nanorod Arrays.

As an analogue to the vapor–liquid–solid process, the solution–liquid–solid (SLS) method offers a mild solution‐phase route to colloidal 1D nanostructures with controlled sizes, compositions, and properties. However, direct growth of 1D nanostructure arrays through SLS processes remains in its infancy. Herein, this study shows that SLS processes are also suitable for the growth of nanorod arrays on the substrate. As a proof of concept, seedless growth of silica nanorod arrays on a variety of hydrophilic substrates such as pristine and oxide‐modified glass, metal sheets, Si wafers, and biaxially oriented polypropylene film are demonstrated. Also, the silica nanorod arrays can be used as a new platform for the fabrication of catalysts for photothermal CO2 hydrogenation and the reduction of 4‐nitrophenol reactions. This work offers some fundamental insight into the SLS growth process and opens a new avenue for the mild preparation of functional 1D nanostructure arrays for various applications.

Facile synthesis of ternary oxide and the performance of photo-catalysis

Nano-structured Zn2GeO4 photocatalyst was prepared through solution phase route. The as-prepared products were characterized by Brunauer–Emmett–Teller (BET) surface area measurements and scanning electron microscopy (SEM). The experimental results revealed that for photo-degradation of MO, the nano-structured Zn2GeO4 samples with higher surface area have higher photocatalytic performance than bulk Zn2GeO4 synthesized through solid-state reaction.

PH Controlled Synthesis of Tetragonal Cu<sub>2</sub>O Particles

Cuprous oxide (Cu2O) in high yield with controlled shape and size was synthesized via a solution-phase route by reducing cupric sulphate with D-glucose. The solution pH shows strong effects on the size and morphology of the products. The products were characterized by X-ray power diffraction (XRD) and Scanning electron microscope (SEM). The infrared emissivity of Cu2O was tested by Far infrared emissivity measurer S302. The possible crystal growth processes have been proposed.

Interlayer coupling and diode characteristics of heterostructures of solution processed MoS2:ReS2 nanocrystals

Heterostructures of MoS2 and ReS2 nanocrystals were prepared in the solution phase by synthesizing the nanocomposite of these two transition metal dichalocogenides (TMDs). The heterostructure of the bulk nanocrystals of these two TMDs is shown to be forming type II heterojunction, favouring n-n junction like characteristics, exhibiting donor-acceptor like behavior. Raman spectroscopy, XPS, UV–Vis absorption measurements and EDX analysis revealed interlayer coupling, charge transfer interaction between the two TMDs and creation of sulfur vacancies in the nanocomposites. Presence of sulfur vacancies is suggested to further reduce the electron injection barrier at the ITO/MoS2 interface, favouring flow of larger current in the forward bias direction. This conclusion was supported by the electrical characteristics of the drop cast films of the nanocomposite revealing diode characteristics with the rectification ratio of about 25. The ideality factor estimated was slightly higher which could be due to defect and trap states at the interface between the two TMDs. The study shows that by simple solution phase route of the bulk like nanocrystals, diode behavior can be obtained that can be useful for bulk heterojunction solar cell applications.

Synthesis and photo-degradation activity of Zn2GeO4 photocatalyst

Through solution phase route, Zn2GeO4 photocatalyst with the morphology of nanoparticle was prepared. The as-prepared products were characterized by scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) surface area measurements. The results revealed that Zn2GeO4 nanoparticles with higher surface area have higher photocatalytic activity in photo-degradation of MO than Zn2GeO4 prepared through solid-state reaction.

Hierarchical flower-like ZnIn2S4 anchored with well-dispersed Ni12P5 nanoparticles for high-quantum-yield photocatalytic H2 evolution under visible light

Ni12P5 nanoparticles were successfully anchored on hierarchical ZnIn2S4 through a facile solution phase route, and the Ni12P5/ZnIn2S4 composites manifested superior photocatalytic H2 evolution under visible light.

Investigation of γ-AlOOH and NiWO4-coated boehmite micro/nanostructure under UV/visible light photocatalysis

A large-scale boehmite (γ-AlOOH) sphere and NiWO4-coated boehmite micro/nanostructured materials were synthesized via a facile two-step hydrothermal method with microwave irradiation using a solution phase route. The morphologies and structures of the prepared samples were characterized by scanning electron microscopy, high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy, and their optical and photocatalytic properties were also measured. The samples boehmite, AN1 and AN2 (different concentrations by NiWO4) were evaluated under UV/visible-light irradiation, and the AN1 sample showed intense (92.6%) degradation of methyl blue dye of the three samples. This enhancement was explained reasonably by HR-TEM evaluated surface-coated core–shell structured γ-AlOOH@NiWO4 shell width was about 10–15 nm and the core–shell size 120 nm. From the optical analysis, the core–shell heteronanostructure new energy level was attributed to the synergistic effect between NiWO4 and boehmite. In particular, a down-conversion luminescence process at the 450 nm excited energy optimization of redox for the efficient photogeneration of electron–hole pairs. Additionally, trapping measurement showed that O2·− and OH· species generated in the photocatalytic process played a key role in the degradation reaction. Based on these findings, this approach may offer a new strategy for the fabrication of surface-controlled spheres of core/shell structure-based photocatalysts with enhanced efficiency for environmental remediation applications.

Construction of network-like and flower-like 2H-MoSe2 nanostructures coupled with porous g-C3N4 for noble-metal-free photocatalytic H2 evolution under visible light

Colloidally synthesized flower-like and network-like MoSe2 nanostructures are coupled with porous g-C3N4 nanosheets through a facile solution-phase route. Herein, two distinct morphological structures of MoSe2/g-C3N4 hybrid nanocomposites are applied as noble-metal-free photocatalysts for hydrogen (H2) evolution. In the resulting optimally-designed hybrid systems, the optimal flower-like and network-like MoSe2 nanostructures loading is determined to be 5 wt%, attaining a maximum H2 evolution rate of 114.5 μmol h−1 g−1 and 136.8 μmol h−1 g−1, respectively. In comparison with flower-like MoSe2 cocatalysts, the network-like MoSe2 hybridized with g-C3N4 endows excellent photocatalytic H2 evolution activity. This phenomenon stems from the intimate formation of unique sheet-on-sheet nanoarchitecture, which is auspicious for the absorption of light and high-efficiency separation of photoexcited electron-hole pairs to hamper the charge recombination. The present studies elucidate the prevailing role of MoSe2 nanostructures as active catalytic sites for H2 evolution, and importantly, the hybrid systems exhibit high photocatalytic stability. Collectively, the work opens up new insights for the utilization of low-cost MoSe2 nanomaterials as remarkable noble-metal-free cocatalysts for effective photocatalytic H2 generation.

Synthesis of ternary oxide for efficient photo catalytic conversion of CO2

Zn2GeO4 Nan rods were prepared by solution phase route. The morphology and structure of the as-prepared products were characterized by scanning electron microscopy (SEM) and Bruner–Emmett–Teller (BET) surface area measurements. The results revealed that Zn2GeO4 Nan rods with higher surface area have higher photo catalytic activity in photo reduction of CO2 than Zn2GeO4 prepared through solid-state reaction.

Low-temperature solution-phase route to sub-10 nm titanium oxide nanocrystals having super-enhanced photoreactivity

High-purity anatase nanocrystals were prepared by using a low-temperature surfactant-assisted solution-phase method.

Gold-Gilded Zinc Oxide Nanodiamonds: Plasmonic and Morphological Effects

The novel properties, diverse applications and device performance of nanocomposites can be greatly modulated through astute combination of plasmonic and morphological effects. The biosensing sensitivity, semiconducting capability, photocatalytic efficiency and antibacterial efficacy of ZnO nanostructures can be enhanced by a diamond-like morphology of ZnO via incorporation of plasmonic gold owing to their exceptional specific surface area, outstanding photoluminescence and excellent biocompatibility. Toward the realization of this goal, Au-Zno nanodiamonds have been successfully synthesized by a microwave assisted solution phase route without use of any costly solvents, surfactants, substrates, post-synthesis treatment or hazardous ingredients. It shows the ability to control the concentration of Au nanoparticles in ZnO and the evolution of its growth in diamond shape. The synthesized nanocomposites were characterized by high-resolution measurements such as transmission electron microscopy (TEM), diffused reflectance spectroscopy (DRS), energy dispersive X-ray spectroscopy (EDX), X-ray diffractometory (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR), and the results discussed in detail.

Chitosan-Covered Pd@Pt Core-Shell Nanocubes for Direct Electron Transfer in Electrochemical Enzymatic Glucose Biosensor.

Development of biosensors with high sensitivity, high spatial resolution, and low cost has received significant attention for their applications in medical diagnosis, diabetes management, and environment-monitoring. However, achieving a direct electrical contact between redox enzymes and electrode surfaces and enhancing the operational stability still remain as challenges. Inorganic metal nanocrystals (NCs) with precisely controlled shape and surface structure engineered with an appropriate organic coating can help overcome the challenges associated with their stability and aggregation for practical biosensor applications. Herein, we describe a facile, room-temperature, seed-mediated solution-phase route to synthesize monodisperse Pd@Pt core–shell nanocubes with subnanometer-thick platinum (Pt) shells. The enzyme electrode consisting of Pd@Pt core–shell NCs was first covered with a chitosan (CS) polymer and then glucose oxidase (GOx) immobilized by a covalent linkage to the CS. This polymer permits covalent immobilization through active amino (−NH) side groups to improve the stability and preserve the biocatalytic functions while the Pd@Pt NCs facilitate enhanced direct electron transfer (DET) in the biosensor. The resultant biosensor promotes DET and exhibits excellent performance for the detection of glucose, with a sensitivity of 6.82 μA cm–2 mM–1 and a wide linear range of 1–6 mM. Our results demonstrate that sensitive electrochemical glucose detection based on Pd@Pt core–shell NCs provides remarkable opportunities for designing low-cost and sensitive biosensors.