Design, synthesis and applications of core–shell, hollow core, and nanorattle multifunctional nanostructures

Kong

et al. 2019

Adv Elect Materials

nevertheless, they usually put undue emphasis on the capacity of the positive electrode, instead. There are few reports that discuss the negative electrode materials relatively. As a result, the capacity of the negative electrodes is much lower than that of the positive electrodes, and the capacity mismatch between the positive and negative electrodes is more serious. [6] As a matter of fact, similar to "cask effect," the capacity of the negative electrode is the shortest plank for supercapacitor, which decides how much energy capacity the supercapacitor can store. In other words, the way that can increase the capacity of the negative electrode materials, can remedy the low energy density deficiency of supercapacitor. [7] Looking at what predecessors have been developed for constructing the supercapacitor negative electrode, carbon and Fe-based materials are two major electrodes that can be utilized. [8][9][10] Due to the redox characteristic of Fe-based materials, it is believed to have the higher theoretical capacity compared with carbon materials that presents double layer capacitance characteristics. [11] To our disappointment, the poor electrical conductivity, which affects the efficiency of electronic transmission, resulted in low supercapacitor performance embodiment, far less than what was expected. [12,13] Therefore, how to improve the electrical conductivity to enhance the efficiency of electron transfer is the most important factor when designing and fabricating an Fe-based negative electrode material. [14] To address this challenge, one of the strategies is to fabricate composites with carbon materials. [4,15] On account of the excellent electrical conductivity of carbon materials, the Fe-based compand/carbon composites show good electrical conductivity. However, the low theoretical capacity of carbon materials limits the capacity promotion of Fe-based compand/ carbon composites. Another method is to rationally design a hierarchical nanostructure. [5,14,16,17] Core-shell structure is believed to be a good choice, where materials with good electrical conductivity are used as the core and materials with high theoretical capacity are used as the shell. [13,[18][19][20] Therefore, the good electrochemical performance has been ascribed to its unique structure, which endows the electrode with large specific area and facilitates the contact between the electrode and The shortcoming of Fe-based materials, their poor electron transfer efficiency, restricts their electrochemical performance severely. An electric field (E) is induced by an Fe 7 S 8 /α-FeOOH nano-heterostructure (SACF) via two simple immersion steps at room temperature. The charge transfer from α-FeOOH to Fe 7 S 8 spontaneously establishes an intrinsic electric field at the Fe 7 S 8 /α-FeOOH nano-heterostructure boundary. Additionally, the relationship between structure and property is investigated by structural characterization and density functional theory calculations that are used to explain the electron transfer mechanism and good wettabilit...

Section: Resultsmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Electric‐Field‐Assisted Enhanced Electron Transfer to Boost Supercapacitor Negative Electrode Performance for a Fabricated Fe₇S₈/α‐FeOOH Nano‐Heterostructure

Kong

et al. 2019

Adv Elect Materials

“…This arises because of either synergistic interaction between the core and the shell or they offer new physicochemical properties due to their interaction . The properties of core‐shell nanomaterials can be tuned by varying the size, and shape of core/shell or completely changing the composition of core or shell depending upon a desired application …”

Section: Introductionmentioning

confidence: 99%

Synthesis of Zn₂TiO₄@CdS Core‐shell Heteronanostructures by Novel Thermal Decomposition Approach for Photocatalytic Application

Mahajan

Jeevanandam

2019

ChemistrySelect

Zn2TiO4@CdS core‐shell heteronanostructures with Zn2TiO4 as core and CdS nanoparticles as shell have been synthesized for the first time by a novel thermal decomposition approach. The size of CdS nanoparticles in the shell can be easily tuned by varying the amount of single molecular precursor (bis(thiourea)cadmium acetate, [Cd(CS(NH2)2)2]⋅(CH3COO)2). Various state‐of‐art analytical techniques prove the formation of Zn2TiO4@CdS core‐shell heteronanostructures. Powder XRD results confirm the presence of cubic Zn2TiO4 and hexagonal CdS in the core‐shell heteronanostructures. SEM and TEM studies indicate spherical morphology for pure Zn2TiO4 and formation of core‐shell structure in Zn2TiO4@CdS with Zn2TiO4 as core and CdS nanoparticles as shell. XPS measurements prove the presence of Zn2+, Ti4+, Cd2+ and S2− in the Zn2TiO4@CdS core‐shell heteronanostructures. The synthesized Zn2TiO4@CdS core‐shell heteronanostructures were explored for photocatalytic degradation of crystal violet in an aqueous solution. The core‐shell heteronanostructures exhibit better photocatalytic activity as compared to their parent materials.

“…7 Besides, interference techniques, such as PTT and drug delivery systems, have been widely used. New methods, such as magnetic hyperthermia, 8 radio sensitizers, 9 targeted drug delivery systems, 10 absorbance in the near-infrared (NIR) region, 11 and multifunctional core-shell structures, 12 in addition to other attempts, have been used as upgrades, with the goal of accurately and effectively destroying cancer cells. However, destroying cancer cells topically never fulfills the aim of cancer therapy.…”

Section: Introductionmentioning

confidence: 99%

Inhibition of cancer cell migration with CuS@mSiO<sub>2</sub>-PEG nanoparticles by repressing MMP-2/MMP-9 expression

Deng¹,

Zhou²,

Wu³

et al. 2017

IJN

The metastasis of cancer cells is a vital aspect of disease progression and therapy. Although a few nanoparticles (NPs) aimed at controlling metastasis in cancer therapy have been reported, the NPs are normally combined with drugs, yet the direct therapeutic effects of the NPs are not reported. To study the direct influence of NPs on cancer metastasis, the potential suppression capacity of CuS@mSiO 2 -PEG NPs to tumor cell migration, a kind of typical photothermal NPs, was systemically evaluated in this study. Using CuS@mSiO 2 -PEG NP stimulation and a transwell migration assay, we found that the migration of HeLa cells was significantly decreased. This phenomenon may be associated with two classical proteins in metastasis: matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9). In addition, the mechanism may closely associate with non-receptor tyrosine kinase protein (SRC)/focal adhesion kinase (FAK) signaling pathway which varies in vivo and in vitro. To confirm the differences in the expression of SRC and FAK, related inhibitors were studied for additional comparison. Also, the results indicated that even though the migration inhibition was closely related to SRC and FAK signaling pathway, there may be another unknown regulation mechanism existing and its metastasis inhibition was significant. Confirmed by long-term survival curve study, CuS@mSiO 2 -PEG NPs significantly reduced the metastasis of cancer cells and improved the survival rates of metastasis in a mouse model. Thus, we believe that the direct influence of NPs on cancer cell metastasis is a promising study topic.