Synthesis of Spongy Gold Nanocrystals with Pronounced Catalytic Activities

Rashid, Md. Harunar; Bhattacharjee, Rama Ranjan; Kotal, Atanu; Mandal, Tarun K.

doi:10.1021/la060939j

Cited by 226 publications

(164 citation statements)

References 22 publications

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“…This band decreased slightly with increased reduction time and became stable after 45 min without change. This result is in agreement with the previous work by Seoudi et al [33] and Rashid et al (2006) [34].…”

Section: Uv-vis Spectra Of Agnpssupporting

confidence: 94%

Preparation and Characterization of Silver Nanoparticles and Their Use in Catalytic Reduction of 4-Nitrophenol

Al-Marhaby¹,

Seoudi²

2016

WJNSE

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Silver nanoparticles of various sizes were prepared at room temperature using silver nitrate as a precursor, various molar ratios of sodium citrate as a surfactant stabilizing material and sodium borohydride as a reducing agent. The morphology, distribution and sphericity of the particles were assessed in images from a transmission electron microscope (TEM). The sizes of the particles were calculated as being 9, 11 and 14 nm. The effects of the particles' sizes on the plasmon bands were confirmed by ultraviolet-visible spectra measurements. The prepared samples were applied in photo catalysis of 4-Nitrophenol (4-NP), and the rate constant was determined as 0.05 s −1 , 0.0015 s −1 and 0.00021 s −1 for particles of 9 nm, 11 nm and 14 nm, respectively. Due to their high surface energy, the smaller particle sizes were more active in the photo catalytic application.

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Section: Uv-vis Spectra Of Agnpssupporting

confidence: 94%

Preparation and Characterization of Silver Nanoparticles and Their Use in Catalytic Reduction of 4-Nitrophenol

Al-Marhaby¹,

Seoudi²

2016

WJNSE

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“…These results indicate that the 4-NP was not reduced to 4-AP. These data agree with the previous work of polydispersity et al [19]. The catalytic activity of AuNPs that were 4 nm (S1), 7 nm (S2) and 11 nm (S3) in diameter was monitored by measuring the UV-Vis spectrum of 4-NP in the 200 -600 nm range at different times in the presence of NaBH 4 .…”

Section: Photo-catalytic Reduction Of 4-np Using Nabh4 and Colloidal supporting

confidence: 92%

Synthesis, Characterization and Photocatalytic Application of Different Sizes of Gold Nanoparticles on 4-Nitrophenol

Seoudi¹,

Al-Marhaby²

2016

WJNSE

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In this work, different sizes of gold nanoparticles were synthesized at room temperature by using trisodium citrate as a surfactant stabilizing agent and sodium borohydride as a reducing agent. Transmission Electron Microscopy (TEM) confirmed that the samples were synthesized in spherical shapes with three different particle sizes: 4 nm, 7 nm and 11 nm. Ultraviolet-visible spectra measurements were used to analyze the way that surface plasmon bands were affected by the different particles sizes. The effect of sphere size on photocatalytic reduction of 4-Nitrophenol was then studied and the rate constant of the reduction was calculated to be 0.014 s −1 , 0.0091 s −1 and 0.003 s −1 for particles sizes of 4 nm, 7 nm and 11 nm, respectively. The results obtained indicated that small particles were more active in catalytic reduction due to their high surface energy.

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“…[4] Gold nanoparticles (AuN) became an object of great attention due to their interesting electronic, optical and thermal properties and potential applications in the fields of medicine, biology, chemistry, physics and material sciences. [5] The AuN have been reported as both toxic and non-toxic. [6,7] AuN were used as markers for tracking signal transduction in cells, which also suggests their non-toxic nature.…”

Section: Introductionmentioning

confidence: 99%

Gold nanoparticles and ions – friends or foes? As they are seen by human cells U-937 and HL-60

Barbasz

Oćwieja

2015

Journal of Experimental Nanoscience

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Gold nanoparticles (AuN) are one of the most investigated nanomaterials, finding numerous applications from medicine to industry. AuN were obtained by reduction of gold salts using tannic acid as a reducing agent. To detach the impact of AuN onto cells of two lines human monocytic cells (U-937) and human promyelocytic leukaemia cells (HL-60), the effects of postreaction residues (of effluent from sol cleaning) and gold ions were also examined. It was demonstrated that resistance of cells to the toxic action of AuN is dependent not only on incubation time and dosage, but also on stages of cell differentiation. It was found that after incubation of promonocytes U-937 with 25 ppm AuN, the cell viability decreased by 25% and of macrophages by 50%. Differentiated cells U-937 showed a significantly lower resistance than the not-differentiated cells. For HL-60 cells, regardless of differentiation, cell viability decreased by approximately 20% after treatment with 25 ppm AuN sol. It was noticed that U-937 exhibited higher vulnerability to AuN than HL-60 cells. It was proved that AuN induced over a 15-fold increase in nitric oxide and a decrease of intracellular glutathione levels indicating the inflammatory response of cells. Even though gold ions did not show a significant effect on cell viability, they caused fivefold increase of nitric oxide level. The results show a higher cytotoxicity of AuN than gold ions. An overall picture of the interaction of AuN with human cells of first defence line was obtained. The results indicate that AuN may cause changes in the response of phagocytes in inflammatory conditions.

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Synthesis of Spongy Gold Nanocrystals with Pronounced Catalytic Activities

Cited by 226 publications

References 22 publications

Preparation and Characterization of Silver Nanoparticles and Their Use in Catalytic Reduction of 4-Nitrophenol

Preparation and Characterization of Silver Nanoparticles and Their Use in Catalytic Reduction of 4-Nitrophenol

Synthesis, Characterization and Photocatalytic Application of Different Sizes of Gold Nanoparticles on 4-Nitrophenol

Gold nanoparticles and ions – friends or foes? As they are seen by human cells U-937 and HL-60

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