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Electrochemical Nanoparticle Sizing Via Nano-Impacts: How Large a Nanoparticle Can be Measured?

Bartlett TR, Sokolov SV, Compton RG - ChemistryOpen (2015)

Bottom Line: The 'nano-impacts' technique is an excellent and qualitative in situ method for nanoparticle characterization.Two complementary studies on silver and silver bromide nanoparticles (NPs) were used to assess the large radius limit of the nano-impact method for NP sizing.Noting that by definition a NP cannot be larger than 100 nm in diameter, we have shown that the method quantitatively sizes at the largest limit, the lower limit having been previously reported as ∼6 nm.1.

View Article: PubMed Central - PubMed

Affiliation: Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford South Parks Road, Oxford, OX1 3QZ, UK.

ABSTRACT
The field of nanoparticle (NP) sizing encompasses a wide array of techniques, with electron microscopy and dynamic light scattering (DLS) having become the established methods for NP quantification; however, these techniques are not always applicable. A new and rapidly developing method that addresses the limitations of these techniques is the electrochemical detection of NPs in solution. The 'nano-impacts' technique is an excellent and qualitative in situ method for nanoparticle characterization. Two complementary studies on silver and silver bromide nanoparticles (NPs) were used to assess the large radius limit of the nano-impact method for NP sizing. Noting that by definition a NP cannot be larger than 100 nm in diameter, we have shown that the method quantitatively sizes at the largest limit, the lower limit having been previously reported as ∼6 nm.1.

No MeSH data available.


Average spike area as a function of applied potential in 0.10 m NaNO3. Dotted line indicates the switch-on potential for AgBr NP reduction. The numbers by each point indicate the number of spikes averaged to produce each data point.
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fig05: Average spike area as a function of applied potential in 0.10 m NaNO3. Dotted line indicates the switch-on potential for AgBr NP reduction. The numbers by each point indicate the number of spikes averaged to produce each data point.

Mentions: To investigate the effect of applied potential on the impact features, the voltage was varied, and the average area of the spikes calculated. Figure 5 shows the average spike area (charge) plotted as a function of applied potential. A clear switch on after −0.75 V is observed, with the average spike charge reaching a steady value consistent with full electrolysis of the particle. The errors reflect the number of impacts measured for each data point which vary significantly. This onset corresponds with the earliest observable reductive features in the stripping voltammetry of the drop cast particles and indicates a significant nucleation overpotential for the reduction of impacting AgBr NPs as seen with the drop-cast particles.


Electrochemical Nanoparticle Sizing Via Nano-Impacts: How Large a Nanoparticle Can be Measured?

Bartlett TR, Sokolov SV, Compton RG - ChemistryOpen (2015)

Average spike area as a function of applied potential in 0.10 m NaNO3. Dotted line indicates the switch-on potential for AgBr NP reduction. The numbers by each point indicate the number of spikes averaged to produce each data point.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608527&req=5

fig05: Average spike area as a function of applied potential in 0.10 m NaNO3. Dotted line indicates the switch-on potential for AgBr NP reduction. The numbers by each point indicate the number of spikes averaged to produce each data point.
Mentions: To investigate the effect of applied potential on the impact features, the voltage was varied, and the average area of the spikes calculated. Figure 5 shows the average spike area (charge) plotted as a function of applied potential. A clear switch on after −0.75 V is observed, with the average spike charge reaching a steady value consistent with full electrolysis of the particle. The errors reflect the number of impacts measured for each data point which vary significantly. This onset corresponds with the earliest observable reductive features in the stripping voltammetry of the drop cast particles and indicates a significant nucleation overpotential for the reduction of impacting AgBr NPs as seen with the drop-cast particles.

Bottom Line: The 'nano-impacts' technique is an excellent and qualitative in situ method for nanoparticle characterization.Two complementary studies on silver and silver bromide nanoparticles (NPs) were used to assess the large radius limit of the nano-impact method for NP sizing.Noting that by definition a NP cannot be larger than 100 nm in diameter, we have shown that the method quantitatively sizes at the largest limit, the lower limit having been previously reported as ∼6 nm.1.

View Article: PubMed Central - PubMed

Affiliation: Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford South Parks Road, Oxford, OX1 3QZ, UK.

ABSTRACT
The field of nanoparticle (NP) sizing encompasses a wide array of techniques, with electron microscopy and dynamic light scattering (DLS) having become the established methods for NP quantification; however, these techniques are not always applicable. A new and rapidly developing method that addresses the limitations of these techniques is the electrochemical detection of NPs in solution. The 'nano-impacts' technique is an excellent and qualitative in situ method for nanoparticle characterization. Two complementary studies on silver and silver bromide nanoparticles (NPs) were used to assess the large radius limit of the nano-impact method for NP sizing. Noting that by definition a NP cannot be larger than 100 nm in diameter, we have shown that the method quantitatively sizes at the largest limit, the lower limit having been previously reported as ∼6 nm.1.

No MeSH data available.