Limits...
Yucca-derived synthesis of gold nanomaterial and their catalytic potential.

Krishnamurthy S, Esterle A, Sharma NC, Sahi SV - Nanoscale Res Lett (2014)

Bottom Line: Varying pH of the solution significantly influenced the particle shape with the production of largely spherical particles at pH 5 to 6 and truncated triangles at pH 2.The catalytic function of Yucca-derived AuNPs was demonstrated by degradation of a wastewater dye: methylene blue using spectrophotometric measurements over time.Treatment with Au nanosheets and spheres demonstrated methylene blue degradation approximately 100% greater than the activity in control at 60 min.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biology, Western Kentucky University, 1906 College Heights Boulevard, Bowling Green 42101-1080, KY, USA.

ABSTRACT
AuNPs ranging in 20 to 300 nm size were synthesized at a room temperature using Yucca filamentosa leaf extract. Diverse nanomaterial morphologies were obtained by varying the extract concentration, reaction pH, and temperature. While low volumes of extract (0.25 and 0.5 mL) induced the formation of microscale Au sheets with edge length greater than 1 μm, high volumes yielded spherical particles ranging from 20 to 200 nm. Varying pH of the solution significantly influenced the particle shape with the production of largely spherical particles at pH 5 to 6 and truncated triangles at pH 2. Separation of multidimensional nanostructures was achieved using a novel method of sucrose density gradient centrifugation. The catalytic function of Yucca-derived AuNPs was demonstrated by degradation of a wastewater dye: methylene blue using spectrophotometric measurements over time. Treatment with Au nanosheets and spheres demonstrated methylene blue degradation approximately 100% greater than the activity in control at 60 min.

No MeSH data available.


Related in: MedlinePlus

Degradation of methylene blue by different nanostructures over 0 to 60 min.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4256969&req=5

Figure 6: Degradation of methylene blue by different nanostructures over 0 to 60 min.

Mentions: Photocatalysis of dyes and other pollutants is an effective remediation strategy for waste water treatment. In this study, the catalytic activity of AuNPs was substantiated by carrying out the degradation of MB dye using SnCl2 and biogenic AuNPs. Nanoparticles of different shapes and sizes obtained under above physicochemical conditions were tested for their catalytic properties. They included the following: (i) anisotropic microscale sheets obtained using 0.5 mL extract, (ii) spherical nanoparticles obtained at 100°C, (iii) commercially obtained citrate capped AuNPs for comparison, and (iv) polydisperse AuNPs synthesized at room temperature and native pH 4.2 of gold salt using 1 mL Yucca extract. The decolorization of MB using SnCl2 was monitored by a spectrophotometer (Figure 6). Addition of different AuNPs in MB solution resulted in reduction reactions over a period of time. In this case, MB with SnCl2 was used as control. It is evident from Figure 6 that AuNPs enhanced significantly the degradation of MB dye. This increase in photocatalytic activity in the presence of AuNPs is due to its ability to act as a sink for photoinduced electrons and promote the charge transfer process for catalytic activity in presence of SnCl2[35]. It can be clearly seen from the above experiment that the catalytic activity in presence of microscale gold sheets was most efficient for the degradation of dye (Figure 6). It is interesting to observe that the absorbance peak falls drastically in the first 10 min of reaction and then gradually decreases over a period of time. The AuNPs synthesized at 100°C and the heterogeneous mixture of AuNPs show an activity similar to those of commercially obtained citrate capped AuNPs. In the absence of AuNPs (control), only 46% of the dye was found degraded after 60 min of reaction. On the contrary, the photocatalytic degradation of the dye was found to be 89% and 81% in presence of Au nanosheets and spherical AuNPs, respectively. (Additional file1: Table S1) The results clearly indicate that AuNPs enhance the photocatalytic degradation of methylene blue in the presence of SnCl2. Single factor ANOVA was performed in order to analyze the variance in different samples. The p value for this analysis was found to be p <0.05, which is an evidence for significant difference in photocatalytic activity of different samples. Anisotropic particles possess better positional order of FCC lattice in comparison with the spherical counterparts[36]. This allows face-to-face interaction and immediate absorption of MB on microscale Au sheets[35], due to which we can see an immediate drop in absorbance during the initial stage of the reaction. Hence, anisotropic AuNPs degrade MB dye more efficiently. These results clearly indicate that properties of biogenic nanoparticles can be controlled using various parameters and made suitable for use as an efficient photocatalyst.


Yucca-derived synthesis of gold nanomaterial and their catalytic potential.

Krishnamurthy S, Esterle A, Sharma NC, Sahi SV - Nanoscale Res Lett (2014)

Degradation of methylene blue by different nanostructures over 0 to 60 min.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4256969&req=5

Figure 6: Degradation of methylene blue by different nanostructures over 0 to 60 min.
Mentions: Photocatalysis of dyes and other pollutants is an effective remediation strategy for waste water treatment. In this study, the catalytic activity of AuNPs was substantiated by carrying out the degradation of MB dye using SnCl2 and biogenic AuNPs. Nanoparticles of different shapes and sizes obtained under above physicochemical conditions were tested for their catalytic properties. They included the following: (i) anisotropic microscale sheets obtained using 0.5 mL extract, (ii) spherical nanoparticles obtained at 100°C, (iii) commercially obtained citrate capped AuNPs for comparison, and (iv) polydisperse AuNPs synthesized at room temperature and native pH 4.2 of gold salt using 1 mL Yucca extract. The decolorization of MB using SnCl2 was monitored by a spectrophotometer (Figure 6). Addition of different AuNPs in MB solution resulted in reduction reactions over a period of time. In this case, MB with SnCl2 was used as control. It is evident from Figure 6 that AuNPs enhanced significantly the degradation of MB dye. This increase in photocatalytic activity in the presence of AuNPs is due to its ability to act as a sink for photoinduced electrons and promote the charge transfer process for catalytic activity in presence of SnCl2[35]. It can be clearly seen from the above experiment that the catalytic activity in presence of microscale gold sheets was most efficient for the degradation of dye (Figure 6). It is interesting to observe that the absorbance peak falls drastically in the first 10 min of reaction and then gradually decreases over a period of time. The AuNPs synthesized at 100°C and the heterogeneous mixture of AuNPs show an activity similar to those of commercially obtained citrate capped AuNPs. In the absence of AuNPs (control), only 46% of the dye was found degraded after 60 min of reaction. On the contrary, the photocatalytic degradation of the dye was found to be 89% and 81% in presence of Au nanosheets and spherical AuNPs, respectively. (Additional file1: Table S1) The results clearly indicate that AuNPs enhance the photocatalytic degradation of methylene blue in the presence of SnCl2. Single factor ANOVA was performed in order to analyze the variance in different samples. The p value for this analysis was found to be p <0.05, which is an evidence for significant difference in photocatalytic activity of different samples. Anisotropic particles possess better positional order of FCC lattice in comparison with the spherical counterparts[36]. This allows face-to-face interaction and immediate absorption of MB on microscale Au sheets[35], due to which we can see an immediate drop in absorbance during the initial stage of the reaction. Hence, anisotropic AuNPs degrade MB dye more efficiently. These results clearly indicate that properties of biogenic nanoparticles can be controlled using various parameters and made suitable for use as an efficient photocatalyst.

Bottom Line: Varying pH of the solution significantly influenced the particle shape with the production of largely spherical particles at pH 5 to 6 and truncated triangles at pH 2.The catalytic function of Yucca-derived AuNPs was demonstrated by degradation of a wastewater dye: methylene blue using spectrophotometric measurements over time.Treatment with Au nanosheets and spheres demonstrated methylene blue degradation approximately 100% greater than the activity in control at 60 min.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biology, Western Kentucky University, 1906 College Heights Boulevard, Bowling Green 42101-1080, KY, USA.

ABSTRACT
AuNPs ranging in 20 to 300 nm size were synthesized at a room temperature using Yucca filamentosa leaf extract. Diverse nanomaterial morphologies were obtained by varying the extract concentration, reaction pH, and temperature. While low volumes of extract (0.25 and 0.5 mL) induced the formation of microscale Au sheets with edge length greater than 1 μm, high volumes yielded spherical particles ranging from 20 to 200 nm. Varying pH of the solution significantly influenced the particle shape with the production of largely spherical particles at pH 5 to 6 and truncated triangles at pH 2. Separation of multidimensional nanostructures was achieved using a novel method of sucrose density gradient centrifugation. The catalytic function of Yucca-derived AuNPs was demonstrated by degradation of a wastewater dye: methylene blue using spectrophotometric measurements over time. Treatment with Au nanosheets and spheres demonstrated methylene blue degradation approximately 100% greater than the activity in control at 60 min.

No MeSH data available.


Related in: MedlinePlus