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Full-Text Articles in Nanoscience and Nanotechnology
Synthesis And Consolidation Of Metal Oxide Nanocrystals Via Nonthermal Plasma, Austin Cendejas
Synthesis And Consolidation Of Metal Oxide Nanocrystals Via Nonthermal Plasma, Austin Cendejas
McKelvey School of Engineering Theses & Dissertations
Nonthermal plasmas offer a unique nonequilibrium environment that has been leveraged in a wide variety of applications in the fields of material processing, lighting, and waste management to name a few. In all of these cases, the plasma serves as a source of high energy electrons, ions, reactive gas species, and radicals that interact in several ways with surfaces brought into contact with the plasma. Specifically, nonthermal plasmas have been shown to be very successful in achieving continuous, high-throughput, monodisperse nanocrystals of a wide variety of materials. The crystallinity of nanoparticles synthesized in nonthermal plasmas can be attributed to the …
Green-Route Synthesis Of Halide Perovskite Materials And Their Optoelectronic Properties, Xiaobing Tang
Green-Route Synthesis Of Halide Perovskite Materials And Their Optoelectronic Properties, Xiaobing Tang
Theses and Dissertations--Chemical and Materials Engineering
Colloidal semiconductor quantum dots (QDs), also called as nanocrystals (NCs), are a class of functional materials with extraordinary properties, which are different from their bulk counterparts and benefit from their exclusive quantum confinement (size) effect. Semiconductor exhibits the quantum confinement effect when the characteristic size of the semiconductor is comparable to or smaller than the de Broglie wavelength of the electron wave function and/or the exciton Bohr diameter of the bulk semiconductor. In recent years, metal halide perovskite NCs, as next-generation semiconductor materials for lighting and display, have aroused a wide attention due to their excellent optoelectronic properties. However, traditional …
Incorporation Of Zinc In Pre-Alloyed Cuin[Zn]S2/Zns Quantum Dots, Jean Carlos Morales Orocu
Incorporation Of Zinc In Pre-Alloyed Cuin[Zn]S2/Zns Quantum Dots, Jean Carlos Morales Orocu
Graduate Theses and Dissertations
Since the early 2000s heavy-metal-free quantum dots (QDs) such as CuInS2/ZnS have attempted to replace CdSe, their heavy-metal-containing counterparts. CuInS2/ZnS is synthesized in a two-step process that involves the fabrication of CuInS2 (CIS) nanocrystals (NCs) followed by the addition of zinc precursors. Instead of the usual core/shell architecture often exhibited by binary QDs, coating CIS QDs results in alloyed and/or partially alloyed cation-exchange (CATEX) QDs. The effect that zinc has on the properties of CIS NCs was studied by incorporating zinc during the first step of the synthesis. Different In:Cu:Zn ratios were employed in this study, maintaining a constant 4:1 …
Magnetic And Catalytic Properties Of Transition Metal Doped Mos2 Nanocrystals, Luis Martinez
Magnetic And Catalytic Properties Of Transition Metal Doped Mos2 Nanocrystals, Luis Martinez
Open Access Theses & Dissertations
Magnetism and catalytic activity of nanoscale layered two-dimensional (2D) transition metal dichalcogenides (TMDs) have gained an increasing research interest in the recent past. To broaden the current knowledge and understanding on this subject, in this work, together with my collaborators, I study the magnetic and electrocatalytic properties of hydrothermally grown pristine and transition metal doped (10% of Co, Ni, Fe and Mn) 2H-MoS2 nanosheets/nanocrystals (NCs), with the particle size of 25-30 nm. A broad range of experimental measurements such as x-ray diffraction, transmission electron microscopy, x-ray photo absorption spectroscopy, Raman spectroscopy, magnetic, catalytic and electron spin resonance have been employed …
The Dawn Of New Quantum Dots: Synthesis And Characterization Of Ge1-Xsnx Nanocrystals For Tunable Bandgaps., Richard J. Esteves
The Dawn Of New Quantum Dots: Synthesis And Characterization Of Ge1-Xsnx Nanocrystals For Tunable Bandgaps., Richard J. Esteves
Theses and Dissertations
Ge1-xSnx alloys are among a small class of benign semiconductors with composition tunable bandgaps in the near-infrared spectrum. As the amount of Sn is increased the band energy decreases and a transition from indirect to direct band structure occurs. Hence, they are prime candidates for fabrication of Si-compatible electronic and photonic devices, field effect transistors, and novel charge storage device applications. Success has been achieved with the growth of Ge1-xSnx thin film alloys with Sn compositions up to 34%. However, the synthesis of nanocrystalline alloys has proven difficult due to larger discrepancies (~14%) in …
Synthesis And Electrocatalysis Of Pdcu Alloy Nanocrystals, Hai-Bin Wu, Rui-Zhong Zhang, Wei Chen
Synthesis And Electrocatalysis Of Pdcu Alloy Nanocrystals, Hai-Bin Wu, Rui-Zhong Zhang, Wei Chen
Journal of Electrochemistry
Monodispersed PdCu alloy nanoparticles were synthesized by co-reduction of Cu(acac)2 and Pd(acac)2 with 1, 2-hexadecanediol. The spherical and popcorn-like shapes of PdCu alloy nanoparticles were obtained by changing the ratios of mixed surface protecting ligands of 1-octadecene, and oleylamine or oleic acid. TEM and XRD measurements showed that both PdCu nanoparticles are alloy nanocrystals dominated with (111) planes and the average sizes are 12.7 ± 0.18 and 20.4 ± 0.31 nm for he spherical and popcorn-like PdCu nanoparticles, respectively. The electrocatalytic activities of the PdCu nanocrystals for formic acid oxidation were evaluated by electrochemical cyclic voltammetry (CV). The result showed …
Semiconductor Nanocrystals: From Quantum Dots To Quantum Disks, Zheng Li
Semiconductor Nanocrystals: From Quantum Dots To Quantum Disks, Zheng Li
Graduate Theses and Dissertations
The bottom-up colloidal synthesis opened up the possibility of finely tuning and tailoring the semiconductor nanocrystals. Numerous recipes were developed for the preparation of colloidal semiconductor nanocrystals, especially the traditional quantum dots. However, due to the lack of thorough understanding to those systems, the synthesis chemistry is still on the empirical level. CdS quantum dots synthesis in non-coordinating solvent were taken as a model system to investigate its molecular mechanism and formation process, ODE was identified as the reducing agent for the preparation of CdS nanocrystals, non-injection and low-temperature synthesis methods developed. In this model system, we not only proved …
Nanosized Molecular Sieves Utilized As An Environmentally Friendly Alternative To Antioxidants For Lubricant Oils, Eng-Poh Ng Dr.
Nanosized Molecular Sieves Utilized As An Environmentally Friendly Alternative To Antioxidants For Lubricant Oils, Eng-Poh Ng Dr.
Eng-Poh Ng
Lubricants play a significant part in current environmental considerations since they are an integral and indispensable component of modern technology. The production, application and disposal of the lubricants have to follow increasingly strict requirements for protecting the environment and living organisms. In this respect, molecular sieve (LTL type zeolite) is investigated as a potential environmentally friendly alternative to traditional antioxidant additives for lubricant oils. Accelerated oxidation experiments using pure base oil and additivated base oil in the presence of the LTL molecular sieve are carried out in parallel, and the oxidation processes are monitored by FT-IR spectroscopy, spectrophotometry, chromatography, total …
Optical Properties Of Photopolymer Layers Doped With Aluminophosphate Nanocrystals, Eng-Poh Ng Dr.
Optical Properties Of Photopolymer Layers Doped With Aluminophosphate Nanocrystals, Eng-Poh Ng Dr.
Eng-Poh Ng
The optical properties of photopolymer layers consisting of an acrylamide-based matrix and microporous aluminophosphate nanocrystals of AEI type are investigated. The compatibility of the photopolymer doped with the nanoparticles is studied. The surface and volume properties of the layers with different levels of doping with microporous nanocrystals are characterized. The effective refractive indices and absorption coefficients of the doped photopolymer layers are determined and used to calculate the refractive index and porosity of pure AEI nanoparticles used as dopants. Volume transmission gratings were recorded in the doped photopolymer layers at different spatial frequencies. By spatial monitoring of the characteristic Raman …
What More In Nanosized Molecular Sieves, Eng-Poh Ng, Gerardo Majano, Louwanda Lakiss, Svetlana Mintova
What More In Nanosized Molecular Sieves, Eng-Poh Ng, Gerardo Majano, Louwanda Lakiss, Svetlana Mintova
Eng-Poh Ng
No abstract provided.