Small-particle research: physicochemical properties of extremely small colloidal metal and semiconductor particles

Henglein, A.

doi:10.1021/cr00098a010

Cited by 2,859 publications

(1,680 citation statements)

References 14 publications

Supporting

Mentioning

1,611

Contrasting

Unclassified

Order By: Relevance

“…13 Although the thermodynamic properties of nanoparticles differ from those of the bulk material, 47,48 the conclusions based on thermodynamic calculations are still valid since silver metal becomes less thermodynamically stable as its size decreases. 13,49,50 Thus, the question of AgNP dissolution becomes one of chemical kinetics.…”

Section: Silver Nanoparticle Dissolutionmentioning

confidence: 99%

“…50,56 Theoretical and experimental work has shown that as particle size decreases, redox potential becomes more negative, which means that small particles will be more readily oxidized and will be less thermodynamically stable than larger particles of the same material. 49,50,57 This decrease in redox potential has been related to the increase in surface free energy that occurs as surface area increases. 47,57 The enhanced reactivity of nanomaterials can also be attributed to their large number of edges, corners, and high energy surface defects.…”

Section: Effects Of Size Shape and Crystallinity On Agnp Dissolutionmentioning

confidence: 99%

See 1 more Smart Citation

Controlled Evaluation of Silver Nanoparticle Dissolution Using Atomic Force Microscopy

Kent

Vikesland

2012

Environ. Sci. Technol.

125

128

View full text Add to dashboard Cite

Incorporation of silver nanoparticles (AgNPs) into an increasing number of consumer products has led to concern over the potential ecological impacts of their unintended release to the environment. Dissolution is an important environmental transformation that affects the form and concentration of AgNPs in natural waters; however, studies on AgNP dissolution kinetics are complicated by nanoparticle aggregation. Herein, nanosphere lithography (NSL) was used to fabricate uniform arrays of AgNPs immobilized on glass substrates. Nanoparticle immobilization enabled controlled evaluation of AgNP dissolution in an air-saturated phosphate buffer (pH 7, 25 °C) under variable NaCl concentrations in the absence of aggregation. Atomic force microscopy (AFM) was used to monitor changes in particle morphology and dissolution. Over the first day of exposure to ≥10 mM NaCl, the in-plane AgNP shape changed from triangular to circular, the sidewalls steepened, and the height increased by 6-12 nm. Subsequently, particle height and inplane radius decreased at a constant rate over a 2-week period. Dissolution rates varied linearly from 0.4 to 2.2 nm/d over the 10-550 mM NaCl concentration range tested. NaCl-catalyzed dissolution of AgNPs may play an important role in AgNP fate in saline waters and biological media. This study demonstrates the utility of NSL and AFM for the direct investigation of unaggregated AgNP dissolution.iii Acknowledgements I thank my advisor, Dr. Peter Vikesland, for his insight, guidance, and innovative ideas throughout my time at Virginia Tech, and for giving me the opportunity to work on this research project. He was ready and available to help whenever I needed his input. I also thank the other members of my committee,

show abstract

Section: Silver Nanoparticle Dissolutionmentioning

confidence: 99%

Section: Effects Of Size Shape and Crystallinity On Agnp Dissolutionmentioning

confidence: 99%

Controlled Evaluation of Silver Nanoparticle Dissolution Using Atomic Force Microscopy

Kent

Vikesland

2012

Environ. Sci. Technol.

125

128

View full text Add to dashboard Cite

show abstract

“…The idea to carry out this process with 'miniaturized photoelectrochemical cells' suspended in water gained traction after Arthur Nozik formulated the concept of 'photochemical diodes' [29]. This was quickly followed by experimental demonstrations of photocatalytic effects in suspended semiconductor particles by Bard [43], and on 'colloidal microelectrodes' by Henglein [54,73]. In 1979, Michael Grätzel reported photocatalytic water oxidation by a suspended RuO 2 nanoparticle in the presence of a [Ru(bipy) 3 ] 2+ complex for visible light absorption and methyl viologen (MV 2+ ) as sacrificial electron acceptor [74].…”

Section: Brief History Of Nanoscale Water Splitting Photocatalysismentioning

confidence: 99%

Nanoscale Effects in Water Splitting Photocatalysis

Osterloh

2015

Topics in Current Chemistry

View full text Add to dashboard Cite

From a conceptual standpoint, the water photoelectrolysis reaction is the simplest way to convert solar energy into fuel. It is widely believed that nanostructured photocatalysts can improve the efficiency of the process and lower the costs. Indeed, nanostructured light absorbers have several advantages over traditional materials. This includes shorter charge transport pathways and larger redox active surface areas. It is also possible to adjust the energetics of small particles via the quantum size effect or with adsorbed ions. At the same time, nanostructured absorbers have significant disadvantages over conventional ones. The larger surface area promotes defect recombination and reduces the photovoltage that can be drawn from the absorber. The smaller size of the particles also makes electron-hole separation more difficult to achieve. This chapter discusses these issues using selected examples from the literature and from the laboratory of the author.

show abstract

“…Since the pioneering work of Brus, Ekimov, and many others in the early 1980-1990s [1][2][3][4][5][6][7][8][9][10][11][12][13], the study of semiconductor nanocrystals (NCs) has developed into a mature, dynamic and multidisciplinary research field, which attracts increasing attention worldwide, both for its fundamental challenges and its potential for a number of technologies (light emitting devices, solar cells, luminescent solar concentrators, optoelectronics, sensing, thermoelectrics, biomedical applications, catalysis) [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. Colloidal semiconductor NCs are particularly attractive, since they consist of an inorganic core that is coated with a stabilizing layer of (usually) organic ligand molecules.…”

Section: Introductionmentioning

confidence: 99%

Excited-State Dynamics in Colloidal Semiconductor Nanocrystals

Rabouw

Donegá

2016

Photoactive Semiconductor Nanocrystal Quantum Dots

View full text Add to dashboard Cite

Colloidal semiconductor nanocrystals have attracted continuous worldwide interest over the last three decades owing to their remarkable and unique sizeand shape-, dependent properties. The colloidal nature of these nanomaterials allows one to take full advantage of nanoscale effects to tailor their optoelectronic and physical-chemical properties, yielding materials that combine size-, shape-, and composition-dependent properties with easy surface manipulation and solution processing. These features have turned the study of colloidal semiconductor nanocrystals into a dynamic and multidisciplinary research field, with fascinating fundamental challenges and dazzling application prospects. This review focuses on the excited-state dynamics in these intriguing nanomaterials, covering a range of different relaxation mechanisms that span over 15 orders of magnitude, from a few femtoseconds to a few seconds after photoexcitation. In addition to reviewing the state of the art and highlighting the essential concepts in the field, we also discuss

show abstract

Small-particle research: physicochemical properties of extremely small colloidal metal and semiconductor particles

Cited by 2,859 publications

References 14 publications

Controlled Evaluation of Silver Nanoparticle Dissolution Using Atomic Force Microscopy

Controlled Evaluation of Silver Nanoparticle Dissolution Using Atomic Force Microscopy

Nanoscale Effects in Water Splitting Photocatalysis

Excited-State Dynamics in Colloidal Semiconductor Nanocrystals

Contact Info

Product

Resources

About