Highly active PdPt bimetallic nanoparticles synthesized by one-step bioreduction method: Characterizations, anticancer, antibacterial activities and evaluation of their catalytic effect for hydrogen generation

Author(s):  
Aysenur Aygun ◽  
Fulya Gulbagca ◽  
Elif Esra Altuner ◽  
Muhammed Bekmezci ◽  
Tugba Gur ◽  
...  
Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 369 ◽  
Author(s):  
Arumugam Saravanan ◽  
Moorthy Maruthapandi ◽  
Poushali Das ◽  
John H. T. Luong ◽  
Aharon Gedanken

Carbon dots (CDs) were obtained from medicinal turmeric leaves (Curcuma longa) by a facile one-step hydrothermal method and evaluated for their bactericidal activities against two gram-negative; Escherichia coli, Klebsiella pneumoniae, and two gram-positive counterparts; Staphylococcus aureus, S. epidermidis. The CDs exhibited spherical shapes with a mean size of 2.6 nm. The fluorescence spectra of CDs revealed intense fluorescence at λex/em = 362/429 nm with a bright blue color in an aqueous solution. The CDs showed strong photostability under various environmental conditions (pH, salt, and UV-radiation). The complete bactericidal potency of CDs was 0.25 mg/mL for E.coli and S. aureus after 8 h of exposure, while for K. pneumoniae, and S. epidermidis, the CDs at 0.5 mg/mL good antibacterial effect within 8 h and complete eradication after 24 h of exposure is observed. The release of reactive oxygen species played a crucial role in the death of the bacterial cell. The present study provides a strategy for the preparation of CDs from a medicinal plant and their potential antibacterial activities against four common contagious pathogens.


ACS Catalysis ◽  
2021 ◽  
pp. 8174-8182
Author(s):  
Kailu Guo ◽  
Yantao Wang ◽  
Junfeng Huang ◽  
Min Lu ◽  
Hua Li ◽  
...  

2012 ◽  
Vol 463-464 ◽  
pp. 743-747
Author(s):  
Ygin Chieh Chen ◽  
Jia You Liou ◽  
Wen Jie Lan ◽  
Jyun Yu Chen ◽  
Hong Wen Wang

A heterogeneous structured photo electrode using CDS -modified TiO2nanotube arrays (TNA) was fabricated. The CDS nano particles were precipitated by immersing TNA into NaS and Cd (ClO4)2solution, where the number of immersion gave different amount of CDS precipitates. The effect of CDS on the performance of photochemical cell of TNA was evaluated. FESEM, EDS, XRD and UV-Visible were employed to characterize the structures and properties of CDS -modified TNA heterogeneous structure. The water splitting experiments were carried out using these CDS -modified TNA under standard AM 1.5 solar illumination (100mW/cm2>). An optimum hydrogen generation rate of 20.61μmole/cm2>)h (~0.50 ml/cm2>)h) was obtained. It was considered that the smaller band gap of CDS rendered the electrons a rapid transportation to the TiO2nanotube arrays and the recombination of electron-hole was therefore effectively prevented. In summary, the CDS nano particles were effective in promoting the catalytic effect of TNA for hydrogen production.


2020 ◽  
Vol 13 (06) ◽  
pp. 2051025
Author(s):  
Hongyan Liu ◽  
Qianyu Shi ◽  
Yumei Yang ◽  
Ya-Na Yu ◽  
Yan Zhang ◽  
...  

In this paper, CoO[Formula: see text]Co2P composite nanocatalysts as highly active catalysts were successfully prepared for catalytic hydrolysis of sodium borohydride (NaBH[Formula: see text] to generate hydrogen. For catalyst preparation, pre-synthesized Co(OH)2 nanosheets were uniformly mixed with sodium hypophosphite (NaH2PO[Formula: see text] and then treated through vapor-phase phosphorization process. For characterization, field-emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), N2 adsorption–desorption measurement and X-ray photoelectric spectroscopy (XPS) were carried out, and traditional water-displacement method was performed to measure the hydrogen generation rate (HGR). It was found that component and catalytic activity of the composites were greatly affected by the ratio of Co(OH)2 to NaH2PO2. When the ratio was 2:1, the obtained catalyst composed of CoO and Co2P presented the highest HGR up to 3.94[Formula: see text]L min[Formula: see text] g[Formula: see text] using a 2[Formula: see text]wt.% NaBH[Formula: see text][Formula: see text]wt.% NaOH solution at [Formula: see text]C, and the apparent activation energy was detected as low as 27.4[Formula: see text]kJ mol[Formula: see text]. Additionally, the optimum CoO[Formula: see text]Co2P catalyst still retains 60% of the initial activity after recycling four times.


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