Adsorption kinetics and nanostructure development during layer by layer assembly of graphene nanoplatelets and amorphous carbon nanospheres

Alazemi, Mubarak; Dutta, Indrajit; Wang, F.; Blunk, Richard H.; Angelopoulos, Anastasios P.

doi:10.1016/j.carbon.2010.07.012

Cited by 12 publications

(6 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Layers were formed by cycling the substrate into baths of polymer then Pt nanoparticle suspensions for 2 and 5 min, respectively, with intervening DI water rinses. The adsorption times were selected to achieve an equilibrated surface concentration of each species based on previous laboratory investigations. − …”

Section: Methodsmentioning

confidence: 99%

“…He demonstrated that only a monolayer of one species remained on the other after rinsing. Since the work of Iler, a vast number of potential applications utilizing electrostatic LbL assembly have been investigated. − Several authors have investigated the electrostatic assembly of gold nanoparticles with various supports for oxygen reduction and other electrocatalytic applications. Li et al used electrostatic attraction between negatively charged Au nanoparticles and positively charged Azure 1 to fabricate a composite Au/multiwalled carbon nanotube (MWCNT) membrane for use as a stable immunosensor .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Enhanced Electrocatalytic Oxygen Reduction through Electrostatic Assembly of Pt Nanoparticles onto Porous Carbon Supports from SnCl₂-Stabilized Suspensions

2011

View full text Add to dashboard Cite

Monodisperse Pt nanoparticles with atomic structures that span the cluster to crystal transition have recently been synthesized in electrostatically stabilized, aqueous-based suspensions. In the present study, the anionic charge from the stabilizing SnCl(2) sheath adsorbed on the surface of these particles is used for the first time to assemble Pt directly onto porous carbon supports via electrostatic assembly. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) reveals that these assemblies have substantially higher Pt-C dispersions than obtained from precipitation methods commonly used for commercial electrocatalyst systems. Energy dispersive spectroscopy (EDS) and inductively coupled plasma-mass spectrometry (ICP-MS) are used to determine that loadings of 10-30% by weight Pt (particle packing fractions from 0.05 to 0.25) are obtained through a single electrostatic application of these particles on Vulcan carbon, depending on particle size. The highest average oxygen reduction reaction (ORR) mass activity obtained using this approach is 90.4 A/g(Pt) at 0.9 V vs RHE in 0.1 M perchloric acid is with 1-2 nm particles that exhibit a transitional atomic structure. This activity compares to an average value of 74.0 A/g(Pt) obtained from densely packed electrostatic layer-by-layer (LbL) assemblies of unsupported particles and 36.7 A/g(Pt) commercial Vulcan electrocatalyst from Tanaka Kikinzoku Kogyo (TKK). Enhanced activity is observed with electrostatic assembly of any particle size on Vulcan relative to unsupported or commercial electrocatalyst with comparable durability. Such enhanced activity is attributed to improved reactant accessibility to the catalyst surface due to the increase in particle dispersion. An extinction coefficient of 7.41 m(2)/g at 352 nm is obtained across the entire cluster to crystal transition from 20 atom clusters to 2.9 nm single crystal nanoparticles, indicating that observed variation in ORR activity with particle size may be associated primarily with changes in atomic surface structure as opposed to the metallic character of the nanoparticles as assessed by UV-vis spectroscopy.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Enhanced Electrocatalytic Oxygen Reduction through Electrostatic Assembly of Pt Nanoparticles onto Porous Carbon Supports from SnCl₂-Stabilized Suspensions

2011

View full text Add to dashboard Cite

show abstract

“…Layer-by-layer (LBL) assembly allows for precise control over the alignment of the graphene nanosheets and the film microstructure. [223][224][225][226][227][228] In this technique, alternating layers of materials are deposited from a graphene-containing solution and a polymer solution. The adhesion of the alternative layers is accomplished by electrostatic attraction between oppositely charged components/constituents of each layer, hydrophobic attractions or the covalent interactions between the materials within each layer.…”

Section: Graphene-based Thin Filmsmentioning

confidence: 99%

Challenges in Liquid‐Phase Exfoliation, Processing, and Assembly of Pristine Graphene

Parviz¹,

Irin²,

Shah³

et al. 2016

Advanced Materials

137

View full text Add to dashboard Cite

Recent developments in the exfoliation, dispersion, and processing of pristine graphene (i.e., non-oxidized graphene) are described. General metrics are outlined that can be used to assess the quality and processability of various "graphene" products, as well as metrics that determine the potential for industrial scale-up. The pristine graphene production process is categorized from a chemical engineering point of view with three key steps: i) pretreatment, ii) exfoliation, and iii) separation. How pristine graphene colloidal stability is distinct from the exfoliation step and is dependent upon graphene interactions with solvents and dispersants are extensively reviewed. Finally, the challenges and opportunities of using pristine graphene as nanofillers in polymer composites, as well as as building blocks for macrostructure assemblies are summarized in the context of large-scale production.

show abstract

“…Furthermore, this strategy has an additional benet that the areal density can be enhanced by a layer-by-layer approach to create multidimensional hybrid structures of CdSe and graphene with accurate dimensional control. 11 Here we use this novel methodology (Scheme 1) to selectively make thiol (-SH) terminated graphene sheets (Section S1 †) by reacting graphene with the diazonium salt of 4-aminothiophenol (4-ATP) followed by building-up of CdSe quantum dots. Since the -SH group has strong affinity towards CdSe QDs (both -SH and CdSe are so), oleic acid capped CdSe QDs with pre-dened sizes have been effectively exchanged with these thiolated graphene materials by mixing in solution, to make CdSe-graphene hybrids.…”

mentioning

confidence: 99%

Thiolated graphene – a new platform for anchoring CdSe quantum dots for hybrid heterostructures

Debgupta

Pillai

2013

Nanoscale

View full text Add to dashboard Cite

show abstract

Adsorption kinetics and nanostructure development during layer by layer assembly of graphene nanoplatelets and amorphous carbon nanospheres

Cited by 12 publications

References 31 publications

Enhanced Electrocatalytic Oxygen Reduction through Electrostatic Assembly of Pt Nanoparticles onto Porous Carbon Supports from SnCl₂-Stabilized Suspensions

Enhanced Electrocatalytic Oxygen Reduction through Electrostatic Assembly of Pt Nanoparticles onto Porous Carbon Supports from SnCl₂-Stabilized Suspensions

Challenges in Liquid‐Phase Exfoliation, Processing, and Assembly of Pristine Graphene

Thiolated graphene – a new platform for anchoring CdSe quantum dots for hybrid heterostructures

Contact Info

Product

Resources

About

Adsorption kinetics and nanostructure development during layer by layer assembly of graphene nanoplatelets and amorphous carbon nanospheres

Cited by 12 publications

References 31 publications

Enhanced Electrocatalytic Oxygen Reduction through Electrostatic Assembly of Pt Nanoparticles onto Porous Carbon Supports from SnCl2-Stabilized Suspensions

Enhanced Electrocatalytic Oxygen Reduction through Electrostatic Assembly of Pt Nanoparticles onto Porous Carbon Supports from SnCl2-Stabilized Suspensions

Challenges in Liquid‐Phase Exfoliation, Processing, and Assembly of Pristine Graphene

Thiolated graphene – a new platform for anchoring CdSe quantum dots for hybrid heterostructures

Contact Info

Product

Resources

About

Enhanced Electrocatalytic Oxygen Reduction through Electrostatic Assembly of Pt Nanoparticles onto Porous Carbon Supports from SnCl₂-Stabilized Suspensions

Enhanced Electrocatalytic Oxygen Reduction through Electrostatic Assembly of Pt Nanoparticles onto Porous Carbon Supports from SnCl₂-Stabilized Suspensions