scholarly journals Homo–hetero/core–shell structure design strategy of NaYF4 nanocrystals for superior upconversion luminescence

RSC Advances ◽  
2021 ◽  
Vol 11 (34) ◽  
pp. 20746-20751
Author(s):  
Raheel Ahmed Janjua ◽  
Obaid Iqbal ◽  
Muhammad Aqeel Ahmed ◽  
Abdullah A. Al-Kahtani ◽  
Sara Saeed ◽  
...  

Establishment of essential conditions of different phases of NaYF4 and their utilization for the synthesis of core/shell structures to achieve the enhancement of UCL intensities.

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 867
Author(s):  
Lin Guo ◽  
Zhu Mao ◽  
Sila Jin ◽  
Lin Zhu ◽  
Junqi Zhao ◽  
...  

Surface-enhanced Raman scattering (SERS) is a powerful tool in charge transfer (CT) process research. By analyzing the relative intensity of the characteristic bands in the bridging molecules, one can obtain detailed information about the CT between two materials. Herein, we synthesized a series of Au nanorods (NRs) with different length-to-diameter ratios (L/Ds) and used these Au NRs to prepare a series of core–shell structures with the same Cu2O thicknesses to form Au NR–4-mercaptobenzoic acid (MBA)@Cu2O core–shell structures. Surface plasmon resonance (SPR) absorption bands were adjusted by tuning the L/Ds of Au NR cores in these assemblies. SERS spectra of the core-shell structure were obtained under 633 and 785 nm laser excitations, and on the basis of the differences in the relative band strengths of these SERS spectra detected with the as-synthesized assemblies, we calculated the CT degree of the core–shell structure. We explored whether the Cu2O conduction band and valence band position and the SPR absorption band position together affect the CT process in the core–shell structure. In this work, we found that the specific surface area of the Au NRs could influence the CT process in Au NR–MBA@Cu2O core–shell structures, which has rarely been discussed before.


2017 ◽  
Vol 121 (34) ◽  
pp. 18909-18916 ◽  
Author(s):  
Yiru Zhu ◽  
Shuwen Zhao ◽  
Bin Zhou ◽  
Hao Zhu ◽  
Youfa Wang

RSC Advances ◽  
2017 ◽  
Vol 7 (84) ◽  
pp. 53509-53515 ◽  
Author(s):  
Tao Li ◽  
ZhiChao Wang ◽  
YunRui Duan ◽  
Jie Li ◽  
Hui Li

An abnormal self-organized core/shell structure is formed in the liquid Al–Pb alloy, which can be controlled by confined conditions.


2013 ◽  
Vol 652-654 ◽  
pp. 683-686
Author(s):  
An Dong Yuan ◽  
Yue Lu Zhang ◽  
Wei Guang Yang ◽  
Ji Rong Li ◽  
Yang Liao ◽  
...  

ZnO@ZnS nano-array core-shell structure was synthesized through a solution method using a thioacetamide (TAA) solution in deionized water. The as-synthesized ZnO nano-array and TAA solution were employed to supply zinc and sulfur ions to form the ZnO@ZnS core-shell structures. The properties of the structure were characterized by X-ray diffraction (XRD), Raman spectrum, scanning electron microscopy (SEM) and UV-Vis spectra. The results indicate that ZnO nano-array was coated with ZnS particles. The concentration of TAA solution can affect the diameter, surface roughness and optical properties of the ZnO@ZnS nano-array core-shell structures.


Carbon ◽  
2016 ◽  
Vol 98 ◽  
pp. 582-591 ◽  
Author(s):  
Junxiong Wu ◽  
Xianying Qin ◽  
Cui Miao ◽  
Yan-Bing He ◽  
Gemeng Liang ◽  
...  

2017 ◽  
Vol 5 (12) ◽  
pp. 5865-5872 ◽  
Author(s):  
X. X. Liu ◽  
J. B. Zang ◽  
L. Chen ◽  
L. B. Chen ◽  
X. Chen ◽  
...  

CoO@Co with a core–shell structure coupled with N-rGO used as a superior multifunctional electrocatalyst was obtained using a convenient and controllable technique.


2014 ◽  
Vol 67 (10) ◽  
pp. 1403 ◽  
Author(s):  
Chong Wang ◽  
Min Wang

Electrospinning has attracted great attention in recent years from different industries including biomedical engineering. Owing to the relative ease of fabricating ultrafine fibres with core–shell structures, emulsion electrospinning has been investigated intensively for making nanofibrous delivery vehicles for local and sustained release of bioactive or therapeutic substances, especially biomolecules such as growth factors. In preparing emulsions for electrospinning, different surfactants, ionic or non-ionic, can be used, which may subsequently influence the evolution of the core–shell structure in the electrospun emulsion jet or fibre. In this investigation, emulsions consisting of deionized water or phosphate buffer saline as the water phase, a poly(lactic-co-glycolic acid) solution as the oil phase and Span 80 (a non-ionic surfactant) or sodium dodecyl sulfate (an ionic surfactant) were electrospun into fibres for studying the core–shell structure and its evolution in emulsion electrospun fibres. Different microscopies were employed to study the morphological changes of the water phase in fibre samples collected at different locations along the jet (or fibre) trajectory during emulsion electrospinning. It was found that the evolution of the fibre core–shell structure was significantly different when different surfactants were used. If Span 80 was the surfactant, the water phase within the thick emulsion jet (or fibre) close to the Taylor cone existed in a discrete state whereas in ultrafine fibres collected beyond a certain distance from the Taylor cone, a mostly continuous water-phase core was observed. If sodium dodecyl sulfate was the surfactant, the core–shell structure in the thick jet (or fibre) was irregular but relatively continuous. A single core core–shell structure was eventually developed in ultrafine fibres. The core–shell structure in electrospun fibres and its evolution were also affected by the emulsion composition (e.g. polymer solution concentration, water-phase volume, and ion addition in the water phase).


RSC Advances ◽  
2018 ◽  
Vol 8 (46) ◽  
pp. 26341-26348 ◽  
Author(s):  
Chin-Chi Cheng ◽  
Wei Chih Weng ◽  
Hsueh I Lin ◽  
Jo Lun Chiu ◽  
Hong-Yu Jhao ◽  
...  

A distinctive novel ZnO/ZnS core–shell structure on silicon was reported in this study.


RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 14047-14052
Author(s):  
Bin Zhao ◽  
Lixuan Chen ◽  
Wenyong Liu ◽  
Longjia Wu ◽  
Zizhe Lu ◽  
...  

The exposed Se on QD surface causes non-radiative relaxations which results in a low PLQY. However, the PLQY was improved from less than 8.0% up to above 85.0% by adding tributyl phosphine which can terminate the dangling bonds of the Se.


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