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Microwave-assisted hydrothermal synthesis of BiOCl/Bi2WO6 nanocomposites for the enhancement of photocatalytic efficiency
摘要： In this research, BiOCl/Bi2WO6 nanocomposites were successfully synthesized by a microwave-assisted hydrothermal method. Phase, morphology and optical properties of the as-synthesized products were investigated by X-ray powder diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, field emission scanning electron microscopy and photoluminescence (PL) spectroscopy. The as-synthesized products were BiOCl/Bi2WO6 nanocomposites composed of Bi2WO6 microflowers mixed with BiOCl nanoplates. The photocatalytic properties of BiOCl/Bi2WO6 nanocomposites were estimated through photodegradation of rhodamine B and salicylic acid as organic models in wastewater. The 80 wt% BiOCl/Bi2WO6 nanocomposites presented the highest photocatalytic efficiency and were certified for the lowest photonic emission by PL analysis. There was a trivial loss of activity even after four re-cycle tests. A mechanism for photocatalysis by BiOCl/Bi2WO6 nanocomposites was also proposed.
关键词： BiOCl/Bi2WO6 nanocomposites,Photocatalysis,Microwave-assisted hydrothermal synthesis
更新于2025-09-23 15:22:29
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Plasma-Assisted Chemical Vapor Synthesis of Aluminum-Doped Zinc Oxide Nanopowder and Synthesis of AZO Films for Optoelectronic Applications
摘要： Transparent conducting oxide aluminum-doped zinc oxide (AZO) nanoparticles were synthesized by a plasma-assisted chemical vapor synthesis route using zinc nitrate and aluminum nitrate as the precursors. The injected precursors vaporized in the plasma flame, followed by vapor-phase reaction and subsequent quenching of the vaporized precursors, producing nanosized AZO powder. The amount of aluminum nitrate was varied to obtain samples with 2 at.%, 4 at.% and 8 at.% Al, designated as AZO1, AZO2 and AZO3, respectively. The XRD patterns of the AZO1 and AZO2 nanoparticles indicated the presence of a wurtzite structure without any alumina peaks except in the AZO3 sample, and scanning electron microscopy micrographs revealed spherical particles. The magnetization measurements revealed a ferromagnetic behavior at room temperature in the AZO1 sample, and the ferromagnetic order is decreased in the high field region with an increase in the Al doping amount. AZO thin films were deposited on glass substrates by spin-coating a dispersion of nanoparticles. All the AZO films had a hexagonal wurtzite structure and exhibited a c-axis preferred orientation perpendicular to the substrate. The Hall effect measurements yielded a minimum resistivity of 9.9 × 10?? Ω cm for the AZO2 film and optical transmission of 80% for both the AZO1 and AZO2 films. However, with 8 at.% Al in the AZO3 film, deterioration in crystallinity, electrical and optical properties were observed. Post-annealing of the AZO1 film in H2 atmosphere caused a significant decrease in resistivity from 1.2 × 10?3 Ω cm to 8.7 × 10?? Ω cm. The optical band gap energies of the AZO films were determined from the transmission spectra. The blue shift in the band gap from 3.2 eV to 3.28 eV, observed with an increase in Al doping, was interpreted by the Burstein–Moss effect. The photoluminescence spectra of the AZO films revealed a UV near-band edge emission and a green emission peak.
关键词： Plasma,optoelectronics,doped-zinc oxide,chemical vapor synthesis
更新于2025-09-23 15:22:29
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Photoelectrochemical Synthesis of Ammonia on the Aerophilic-Hydrophilic Heterostructure with 37.8% Efficiency
摘要： A unique aerophilic-hydrophilic heterostructure composed of Au nanoparticles highly dispersed in a poly(tetrafluoroethylene) porous framework is fabricated on a Si-based photocathode for N2-to-NH3 fixation. The amphipathic nature of the heterostructure is considered to be the origin of the enhanced nitrogen reduction reaction with efficient conversion efficiency and high production rate.
关键词： photoelectrochemical synthesis,ammonia,nitrogen reduction reaction,efficiency,aerophilic-hydrophilic heterostructure
更新于2025-09-23 15:22:29
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Hydrothermal synthesis and photocatalytic properties of CuGaO2/ZnO hexagonal platelet hybrids
摘要： Delafossite CuGaO2 as a p-type semiconductor is classified as a wide band-gap semiconductor owing to direct transitions on the high energy side. Solid state reaction and sol-gel synthesis are applicable as traditional methods for synthesizing delafossite CuGaO2. However, both synthesis methods require high temperatures, and the sol-gel method additionally requires a nitrogen gas atmosphere. In this study, hexagonal-platelet CuGaO2 is synthesized using a hydrothermal method, which can also be adapted to the synthesis of the CuGaO2/ZnO hybrids. As a result, it was found that the surface of platelet CuGaO2 particles could be used to create hybrids with n-type ZnO semiconductors. This paper also presents the optical band-gap energy and photocatalytic properties of hexagonal-platelet CuGaO2 and CuGaO2/ZnO hybrids.
关键词： photocatalytic properties,p-type semiconductor,Hydrothermal synthesis,optical bandgap,hexagonal platelet hybrid
更新于2025-09-23 15:22:29
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Influence of molecular fluorophores on the research field of chemically synthesized carbon dots
摘要： Carbon dots (CDs) – small crystalline or amorphous carbon-based nanoparticles – have attracted much attention as promising fluorescent materials for a wide range of applications. One of their widely accepted advantages is the simplicity of the formation of highly luminescent CDs from a wide variety of organic precursors. At the same time, several recent studies on these chemically synthesized CDs raised questions about the nature of the resulting products. Their strong fluorescence can arise due to the presence of molecular organic fluorophores, not necessary CDs, as was assumed in the earlier publications. In this review, we consider fundamental characteristics of CDs and discuss several issues that currently prevent a better understanding of their structure-property correlation. Analysis of recent related studies identifying the presence of organic fluorophores in CDs with an emphasis on the optical properties of the synthesis products shows that their emission characteristics may be a complex interplay of stand-alone molecular fluorophores and their aggregates, possibly embedded in an amorphous carbon/polymer network. The review concludes with an outlook towards the challenges in the field of the bottom-up synthesized CDs, and their proper identification within the variety of the organic side-products eventually formed during the synthesis.
关键词： Luminescence,Chemical synthesis,Carbon dots,Optical properties,Molecular fluorophores,Aggregation
更新于2025-09-23 15:21:21
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Electrochemical properties of chemically synthesized SnO2-RuO2 mixed films
摘要： The SnO2–RuO2 mixed films are prepared by successive ionic layer adsorption and reaction (SILAR) method. The SnO2 films combined with RuO2 are prepared by varying the deposition cycles of SILAR. The effect of combining SnO2 with RuO2 on structural, morphological and electrochemical properties is studied. It is observed that the crystalline nature of SnO2 changed to amorphous with increase in RuO2 deposition cycles. The morphology is also changed from fibrous-porous to compact after increasing RuO2 deposition cycles. The specific capacitance of SnO2 is increased from 4 to 185 F/g after combined with RuO2. The maximum utilization of RuO2 is observed with specific capacitance of 1010 F/g.
关键词： RuO2,SnO2,Supercapacitor,Thin films,Chemical synthesis,Charge–discharge
更新于2025-09-23 15:21:21
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Chemistry and Structure of Silver Molecular Nanoparticles
摘要： Silver and gold molecular nanoparticles (mNPs) are a relatively new class of interest. They are high-nuclearity metal?organic molecular materials of compounds, with ligated metal cores, where the different character of bonding in the ligand shell and metal core gives rise to many of the unique properties of these materials. Research has primarily focused on gold mNPs, due to their good stability and the ease with which they may be synthesized and processed. To understand these materials as a general class, however, it will be necessary to broaden research efforts to other metals. Gold and silver are isoelectronic and have the same atomic radius, making the comparison of gold and silver mNPs attractive. The optical and chemical differences of the two metals provide useful contrasts, however, as well as a means to access a wider range of properties.
关键词： gold molecular nanoparticles,reactivity,structure,synthesis,silver molecular nanoparticles
更新于2025-09-23 15:21:21
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Tellurium Precursor for Nanocrystal Synthesis: Tris(dimethylamino)phosphine Telluride
摘要： Preparations of CdTe quantum platelets, magic-size (CdTe)13 nanoclusters, and CdTe quantum wires are described using (Me2N)3PTe (with (Me2N)3P) as a Te precursor. The (Me2N)3PTe/(Me2N)3P precursor mixture is shown to be more reactive than mixtures of trialkylphosphine tellurides and the corresponding trialkylphosphines, R3PTe/R3P, which are commonly employed in nanocrystal syntheses. For syntheses conducted in primary amine solvents, (Me2N)3PTe and (Me2N)3P undergo a transamination reaction, affording (Me2N)x(RHN)3?xPTe and (Me2N)x(RHN)3?xP (R = n-octyl or oleyl). The transaminated (Me2N)x(RHN)3?xPTe derivatives are shown to be the likely Te precursors under those conditions. The enhanced reactivities of the tris(amino)phosphine tellurides are ascribed to increased nucleophilicity due to the amino-N lone pairs.
关键词： tris(dimethylamino)phosphine telluride,tellurium precursor,CdTe quantum wires,nanocrystal synthesis,CdTe nanoplatelets,(CdTe)13
更新于2025-09-23 15:21:21
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Dielectric and piezoelectric properties of Sm3+ doped lead barium niobate (PBN) ceramics
摘要： Rhombohedral samarium doped Lead based ceramic materials were fabricated by a high temperature conventional solid state mixed oxide ceramic process. The ceramic composition Pb1-x-3y/2Bax Re3+ y Nb2O6 (x = 0.35 and y=0.00, 0.02, 0.04 and 0.06, Re3+ = Sm3+). The pure and Sm3+ doped lead barium niobate ceramic materials are single phase with rhombohedral(hexagonal) symmetry obtained from powder x-ray diffraction (XRD). The grain size has been measured for all the compositions and lying between 1.60-2.90μm. Broad dielectric peak phase transitions observed with temperature in pure and Sm3+ ion modified lead barium niobate ceramic materials. It is observed that the high values of piezoelectric charge coefficients in d31 and d33 in Sm3+ doped lead barium niobate ceramics. The mechanical quality factor Qm and d33 increases with increase of Sm3+ ion concentration and indicating a highly polarisable lead ion contributing to high Curie temperature dielectric constant.
关键词： SEM,Piezoelectric properties,Rhombohedral,Synthesis of ceramic compositions,dielectric,X-Ray diffraction
更新于2025-09-23 15:21:21
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Convergent and Functional-Group-Tolerant Synthesis of B-Organo BODIPYs
摘要： Boron-dipyrromethenes (BODIPYs) are one of the most important fluorescent materials. Despite their potential unique properties, however, B,B-fluoro-organo BODIPYs (BFR-BODIPYs) possessing an organo group (R) on the boron center have not been studied in detail, due in part to challenges related to their synthesis. In this paper, a convergent synthesis of BFR-BODIPYs operative under mild conditions is reported. Conversions of the thus-synthesized functionalized BFR-BODIPYs by cross-coupling, condensation, and SN2 reactions at the R group are also demonstrated.
关键词： convergent synthesis,Boron-dipyrromethenes,fluorescent materials,BODIPYs,functionalized BFR-BODIPYs
更新于2025-09-23 15:21:21