scholarly journals Ag3PO4@holmium phosphate core@shell composites with enhanced photocatalytic activity

RSC Advances ◽  
2017 ◽  
Vol 7 (55) ◽  
pp. 34705-34713 ◽  
Author(s):  
Fengfeng Li ◽  
Zhihong Li ◽  
Mingxi Zhang ◽  
Yi Shen ◽  
Yongfeng Cai ◽  
...  

In this study, Ag3PO4@holmium phosphate (HP) composite photocatalysts were firstly prepared. The core–shell heterojunction structure of Ag3PO4@HP significantly improved the photocatalytic activity of Ag3PO4.

2013 ◽  
Vol 06 (06) ◽  
pp. 1350058 ◽  
Author(s):  
YUAN MING HUANG ◽  
QING-LAN MA ◽  
BAO-GAI ZHAI

A facile and green method was utilized to synthesize core-shelled Zn / ZnO microspheres by boiling Zn microparticles in water for improving the photocatalytic activity of ZnO . The synthesized Zn / ZnO core-shells were investigated by means of scanning electron microscope, X-ray diffractometer and photoluminescence spectrometer, respectively. The morphology analysis showed that the metallic Zn core was about 6 μm in diameter while the ZnO shell was about 600 nm in thickness. Compared to ZnO nanoparticles, the core-shelled Zn / ZnO microspheres exhibited improved photocatalytic activity in degrading methyl orange in water. Our results suggest that the metal–semiconductor junction formed at the Zn / ZnO interface is responsible for the enhanced photocatalytic activity of ZnO .


2018 ◽  
Vol 6 (11) ◽  
pp. 15867-15875 ◽  
Author(s):  
Naixu Li ◽  
Wenlong Fu ◽  
Chen Chen ◽  
Maochang Liu ◽  
Fei Xue ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Fengyun Guo ◽  
Ziyi Guo ◽  
Lei Gao ◽  
Dongming Qi ◽  
Guichu Yue ◽  
...  

The core-shell NaYF4/Yb/Tm/TiO2 hollow composite fibers were prepared by coaxial electrospinning and high-temperature calcination. The composite fibers exhibit excellent photocatalytic activity under the dual synergistic of regulating the core-shell hollow microstructure and the composition by doping nanoparticles. Compared with commercial P25 and hollow fiber without nanoparticles, the degradation efficiency of rhodamine B using the core-shell composite fiber was significantly improved up to 99%. Moreover, the nanoparticles in the composite fibers can exist stably and maintain good structure and photocatalytic activity after repeated use. Therefore, the composite fiber has a wide application prospect in photocatalytic degradation of organic pollutants.


2016 ◽  
Vol 4 (3) ◽  
pp. 869-876 ◽  
Author(s):  
Jung Bo Yoo ◽  
Hyo Jin Yoo ◽  
Hyuk Joon Jung ◽  
Han Sol Kim ◽  
Sora Bang ◽  
...  

Novel photocatalysts (TiO2@TiO1−xNx) with the core–shell structure, prepared by controlled nitridation of TiO2 microspheres, show photocatalytic activity under visible-light irradiation.


2021 ◽  
Vol 15 (1) ◽  
pp. 58-68
Author(s):  
Shalini Sikdar ◽  
Tiju Thomas ◽  
Rao Ramachandra ◽  
Subramshu Bhattacharya

Conversion of Cr(VI) to Cr(III) in mitigating pollution of water bodies is of significant importance to public health due to the fact that Cr(VI) is known to be a potent carcinogen, while Cr(III) is relatively low in toxicity. Photocatalytic approaches are considered as important means to achieve this reduction. Here, TiO2/SnS2 core-shell nanostructures have been produced using a single-step hydrothermal method and its photocatalytic activity is tested for the reduction of aqueous Cr(VI). The structural and optical properties of the as-synthesized products are characterized by XRD, HRTEM, Raman, FTIR, XPS and DRS techniques. The present work reveals that by calcining the core-shell nanoparticles in Ar atmosphere a defective Ti3O5 phase is formed as the core with low band gap, and hence, offers improved light absorption in the visible range. However, its photoactivity was found to be lower than that of the core-shell nanoparticles annealed in oxidizing atmosphere. The observed lower photoreduction was due to the presence of midgap states which acted as recombination centres and hence, reduced the photocatalytic activity.


2020 ◽  
Vol 65 (10) ◽  
pp. 904
Author(s):  
V. O. Zamorskyi ◽  
Ya. M. Lytvynenko ◽  
A. M. Pogorily ◽  
A. I. Tovstolytkin ◽  
S. O. Solopan ◽  
...  

Magnetic properties of the sets of Fe3O4(core)/CoFe2O4(shell) composite nanoparticles with a core diameter of about 6.3 nm and various shell thicknesses (0, 1.0, and 2.5 nm), as well as the mixtures of Fe3O4 and CoFe2O4 nanoparticles taken in the ratios corresponding to the core/shell material contents in the former case, have been studied. The results of magnetic research showed that the coating of magnetic nanoparticles with a shell gives rise to the appearance of two simultaneous effects: the modification of the core/shell interface parameters and the parameter change in both the nanoparticle’s core and shell themselves. As a result, the core/shell particles acquire new characteristics that are inherent neither to Fe3O4 nor to CoFe2O4. The obtained results open the way to the optimization and adaptation of the parameters of the core/shell spinel-ferrite-based nanoparticles for their application in various technological and biomedical domains.


Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 72
Author(s):  
Christian Zambrzycki ◽  
Runbang Shao ◽  
Archismita Misra ◽  
Carsten Streb ◽  
Ulrich Herr ◽  
...  

Core-shell materials are promising functional materials for fundamental research and industrial application, as their properties can be adapted for specific applications. In particular, particles featuring iron or iron oxide as core material are relevant since they combine magnetic and catalytic properties. The addition of an SiO2 shell around the core particles introduces additional design aspects, such as a pore structure and surface functionalization. Herein, we describe the synthesis and application of iron-based core-shell nanoparticles for two different fields of research that is heterogeneous catalysis and water purification. The iron-based core shell materials were characterized by transmission electron microscopy, as well as N2-physisorption, X-ray diffraction, and vibrating-sample magnetometer measurements in order to correlate their properties with the performance in the target applications. Investigations of these materials in CO2 hydrogenation and water purification show their versatility and applicability in different fields of research and application, after suitable individual functionalization of the core-shell precursor. For design and application of magnetically separable particles, the SiO2 shell is surface-functionalized with an ionic liquid in order to bind water pollutants selectively. The core requires no functionalization, as it provides suitable magnetic properties in the as-made state. For catalytic application in synthesis gas reactions, the SiO2-stabilized core nanoparticles are reductively functionalized to provide the catalytically active metallic iron sites. Therefore, Fe@SiO2 core-shell nanostructures are shown to provide platform materials for various fields of application, after a specific functionalization.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 359
Author(s):  
Francesco Ruffino

Bimetallic nanoparticles show novel electronic, optical, catalytic or photocatalytic properties different from those of monometallic nanoparticles and arising from the combination of the properties related to the presence of two individual metals but also from the synergy between the two metals. In this regard, bimetallic nanoparticles find applications in several technological areas ranging from energy production and storage to sensing. Often, these applications are based on optical properties of the bimetallic nanoparticles, for example, in plasmonic solar cells or in surface-enhanced Raman spectroscopy-based sensors. Hence, in these applications, the specific interaction between the bimetallic nanoparticles and the electromagnetic radiation plays the dominant role: properties as localized surface plasmon resonances and light-scattering efficiency are determined by the structure and shape of the bimetallic nanoparticles. In particular, for example, concerning core-shell bimetallic nanoparticles, the optical properties are strongly affected by the core/shell sizes ratio. On the basis of these considerations, in the present work, the Mie theory is used to analyze the light-scattering properties of bimetallic core–shell spherical nanoparticles (Au/Ag, AuPd, AuPt, CuAg, PdPt). By changing the core and shell sizes, calculations of the intensity of scattered light from these nanoparticles are reported in polar diagrams, and a comparison between the resulting scattering efficiencies is carried out so as to set a general framework useful to design light-scattering-based devices for desired applications.


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