scholarly journals Separable Magnetic Fe3O4@MoS2 Composite for Adsorption and Piezo-Catalytic Degradation of Dye

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1403
Author(s):  
Chi Zhou ◽  
Wencheng Liu ◽  
Hanqing Li ◽  
Miao Yang ◽  
Zixin Yang

Well-designed composite catalysts are of increasing concern due to their improved performance compared to individual components. Herein, we designed and synthesized an Fe3O4@MoS2 composite via a simple hydrothermal method. As for the resultant composite, the MoS2 nanolayers presented a novel piezo-catalytic effect, while the Fe3O4 core provided a magnetic separation property. The structure and properties of Fe3O4@MoS2 were determined by relevant experiments. It was found that Fe3O4@MoS2 exhibited enhanced piezo-catalytic degradation of rhodamine B and good magnetic recovery/recycling features. The kobs for rhodamine B degradation over Fe3O4@MoS2 was 0.019 min−1—a little longer than that over MoS2 (0.013 min−1). Moreover, Fe3O4@MoS2 also showed a favorable ability to adsorb rhodamine B in solution, with a saturation adsorption of 26.8 mg/g. Further studies revealed that piezo-electrons, holes, and superoxide anions were key species in the piezo-catalytic degradation of rhodamine B. Notably, the step where oxygen trapped electrons to produce superoxide anions had a significant impact on the degradation of the dye. This work, not limited to the development of a high-performance MoS2-based piezo-catalyst, is expected to provide new insights into the working mechanisms and process profiles of composite piezo-catalysts.

Author(s):  
C.K. Wu ◽  
P. Chang ◽  
N. Godinho

Recently, the use of refractory metal silicides as low resistivity, high temperature and high oxidation resistance gate materials in large scale integrated circuits (LSI) has become an important approach in advanced MOS process development (1). This research is a systematic study on the structure and properties of molybdenum silicide thin film and its applicability to high performance LSI fabrication.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1130
Author(s):  
Mariana Pires Figueiredo ◽  
Ana Borrego-Sánchez ◽  
Fátima García-Villén ◽  
Dalila Miele ◽  
Silvia Rossi ◽  
...  

This work presents the development of multifunctional therapeutic membranes based on a high-performance block copolymer scaffold formed by polyether (PE) and polyamide (PA) units (known as PEBA) and layered double hydroxide (LDH) biomaterials, with the aim to study their uses as wound dressings. Two LDH layer compositions were employed containing Mg2+ or Zn2+, Fe3+ and Al3+ cations, intercalated with chloride anions, abbreviated as Mg-Cl or Zn-Cl, or intercalated with naproxenate (NAP) anions, abbreviated as Mg-NAP or Zn-NAP. Membranes were structurally and physically characterized, and the in vitro drug release kinetics and cytotoxicity assessed. PEBA-loading NaNAP salt particles were also prepared for comparison. Intercalated NAP anions improved LDH–polymer interaction, resulting in membranes with greater mechanical performance compared to the polymer only or to the membranes containing the Cl-LDHs. Drug release (in saline solution) was sustained for at least 8 h for all samples and release kinetics could be modulated: a slower, an intermediate and a faster NAP release were observed from membranes containing Zn-NAP, NaNAP and Mg-NAP particles, respectively. In general, cell viability was higher in the presence of Mg-LDH and the membranes presented improved performance in comparison with the powdered samples. PEBA containing Mg-NAP sample stood out among all membranes in all the evaluated aspects, thus being considered a great candidate for application as multifunctional therapeutic dressings.


Author(s):  
Zahra Shokri Aghbolagh ◽  
Mohammad Saim Rahmatyan ◽  
Mohammad Reza Khanmohammadi Khorrami

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 589
Author(s):  
Sivagowri Shanmugaratnam ◽  
Balaranjan Selvaratnam ◽  
Aravind Baride ◽  
Ranjit Koodali ◽  
Punniamoorthy Ravirajan ◽  
...  

Earth–abundant transition metal chalcogenide materials are of great research interest for energy production and environmental remediation, as they exhibit better photocatalytic activity due to their suitable electronic and optical properties. This study focuses on the photocatalytic activity of flower-like SnS2 nanoparticles (composed of nanosheet subunits) embedded in TiO2 synthesized by a facile hydrothermal method. The materials were characterized using different techniques, and their photocatalytic activity was assessed for hydrogen evolution reaction and the degradation of methylene blue. Among the catalysts studied, 10 wt. % of SnS2 loaded TiO2 nanocomposite shows an optimum hydrogen evolution rate of 195.55 µmolg−1, whereas 15 wt. % loading of SnS2 on TiO2 exhibits better performance against the degradation of methylene blue (MB) with the rate constant of 4.415 × 10−4 s−1 under solar simulated irradiation. The improved performance of these materials can be attributed to the effective photo-induced charge transfer and reduced recombination, which make these nanocomposite materials promising candidates for the development of high-performance next-generation photocatalyst materials. Further, scavenging experiments were carried out to confirm the reactive oxygen species (ROS) involved in the photocatalytic degradation. It can be observed that there was a 78% reduction in the rate of degradation when IPA was used as the scavenger, whereas around 95% reduction was attained while N2 was used as the scavenger. Notably, very low degradation (<5%) was attained when the dye alone was directly under solar irradiation. These results further validate that the •OH radical and the superoxide radicals can be acknowledged for the degradation mechanism of MB, and the enhancement of degradation efficiency may be due to the combined effect of in situ dye sensitization during the catalysis and the impregnation of low bandgap materials on TiO2.


Nanoscale ◽  
2016 ◽  
Vol 8 (5) ◽  
pp. 2857-2866 ◽  
Author(s):  
Matilde Saura-Múzquiz ◽  
Cecilia Granados-Miralles ◽  
Marian Stingaciu ◽  
Espen Drath Bøjesen ◽  
Qiang Li ◽  
...  

High-performance hexaferrite magnets of aligned single-domain nanoplatelets are obtained by supercritical synthesis and compaction through Spark Plasma Sintering.


2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yongli Zhang ◽  
Shujuan Dai ◽  
Yanbo Zhou ◽  
Kai Lin

Fe-Co-Ce composite catalysts were prepared by coprecipitation method using CO(NH2)2, NaOH, NH4HCO3, and NH3·H2O as precipitant agents. The effects of the precipitant agents on the physicochemical properties of the Fe-Co-Ce based catalysts were investigated by SEM, TEM, BET, TG-DTA, and XRD. It was found that the precipitant agents remarkably influenced the morphology and particle size of the catalysts and affected the COD removal efficiency, decolorization rate, and pH of methyl orange for catalytic wet air oxidation (CWAO). The specific surface area of the Fe-Co-Ce composite catalysts successively decreased in the order of NH3·H2O, NH4HCO3, NaOH, and CO(NH2)2, which correlated to an increasing particle size that increased for each catalyst. For the CWAO of a methyl orange aqueous solutions, the effects of precipitant agents NH3·H2O and NaOH were superior to those of CO(NH2)2and NH4HCO3. The catalyst prepared using NH3·H2O as the precipitant agent was mostly composed of Fe2O3, CoO, and CeO2. The COD removal efficiency of methyl orange aqueous solution for NH3·H2O reached 92.9% in the catalytic wet air oxidation. Such a catalytic property was maintained for six runs.


Nanoscale ◽  
2015 ◽  
Vol 7 (21) ◽  
pp. 9589-9596 ◽  
Author(s):  
Shuangyu Liu ◽  
Guoqing Wang ◽  
Fangfang Tu ◽  
Jian Xie ◽  
Hui Ying Yang ◽  
...  

Porous Au/δ-MnO2on graphene-coated Ni foam exhibited a superior catalytic effect for Li–O2batteries with Au-induced directed Li2O2growth.


Author(s):  
Shuhui Yin ◽  
Qiong Zhu ◽  
Jianyong Liu ◽  
Panwang Zhou

1,1-diamino-2,2-dinitroethene (FOX-7) is a novel energetic material with high performance and low sensitivity. In order to deeply understand the reaction mechanism in the initiation “hot spots” of FOX-7 and reveal the growth mechanism of these initiation “hot spots” in the explosion process, the detailed mechanisms of bimolecular reaction of NO2 and FOX-7, as well as the subsequent reactions have been investigated by the quantum chemical calculations. The mechanism of NO2 and FOX-7 bimolecular reaction and the catalytic effect of NO2 were revealed by three key dissociation paths. It is demonstrated that the NO2 molecule plays an important role in promoting the decomposition of the FOX-7 molecule, and the main exothermic pathways were the reactions between oxidizing intermediates (NO, NO2), and reducing intermediates (CO, NH3).


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