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Uniform Functionalization of High-Quality Graphene with Platinum Nanoparticles for Electrocatalytic Water Reduction.

Mazzaro R, Boni A, Valenti G, Marcaccio M, Paolucci F, Ortolani L, Morandi V, Ceroni P, Bergamini G - ChemistryOpen (2015)

Bottom Line: The turnover frequency at zero overpotential (TOF0 in 0.1 m phosphate buffer, pH 6.8) was determined to be approximately 4600 h(-1).This remarkably high value is likely due to the optimal dispersion of the platinum nanoparticles on the graphene substrate, which enables the material to be loaded with only very small amounts of the noble metal (i.e., Pt) despite the very highly active surface.This study provides a new outlook on the design of novel materials for the development of robust and scalable water-splitting devices.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Chimica "G. Ciamician", Università di Bologna Via Selmi 2, 40126, Bologna, Italy ; Institute for Microelectronics & Microsystems (IMM)-Bologna, National Research Council (CNR) Via Gobetti 101, 40129, Bologna, Italy.

ABSTRACT
Graphene-metal composites have potential as novel catalysts due to their unique electrical properties. Here, we report the synthesis of a composite material comprised of monodispersed platinum nanoparticles on high-quality graphene obtained by using two different exfoliation techniques. The material, prepared via an easy, low-cost and reproducible procedure, was evaluated as an electrocatalyst for the hydrogen evolution reaction. The turnover frequency at zero overpotential (TOF0 in 0.1 m phosphate buffer, pH 6.8) was determined to be approximately 4600 h(-1). This remarkably high value is likely due to the optimal dispersion of the platinum nanoparticles on the graphene substrate, which enables the material to be loaded with only very small amounts of the noble metal (i.e., Pt) despite the very highly active surface. This study provides a new outlook on the design of novel materials for the development of robust and scalable water-splitting devices.

No MeSH data available.


Related in: MedlinePlus

Comparison between decoration of exfoliated graphene produced with different techniques: PCA-G using 1-pyrenecarboxylic acid (PCA) (left) and NMP-G using 1-methyl-2-pyrrolidone (NMP) (right). a,b) Low-magnification scanning transmission electron microscope (STEM) micrographs of decorated graphene flakes. c,d) High-resolution transmission electron microscopy (HR-TEM) micrographs of flake edges covered by platinum nanoparticles. e,f) Size distribution histogram of the platinum nanoparticles synthesized on graphene. The distribution was fitted by using the Lorentz function, and the average diameter is reported in the inset.
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fig02: Comparison between decoration of exfoliated graphene produced with different techniques: PCA-G using 1-pyrenecarboxylic acid (PCA) (left) and NMP-G using 1-methyl-2-pyrrolidone (NMP) (right). a,b) Low-magnification scanning transmission electron microscope (STEM) micrographs of decorated graphene flakes. c,d) High-resolution transmission electron microscopy (HR-TEM) micrographs of flake edges covered by platinum nanoparticles. e,f) Size distribution histogram of the platinum nanoparticles synthesized on graphene. The distribution was fitted by using the Lorentz function, and the average diameter is reported in the inset.

Mentions: Figure 2 shows the comparison between the results of the platinum nanoparticle decoration of exfoliated graphene using the PCA-G and NMP-G methods. The scanning transmission electron microscope (STEM) and HR-TEM micrographs (Figure 2 a–d) clearly show the strong selectivity of the decoration, without any particles outside the platelets, with a slightly lower concentration of particles in the NMP-G sample. We attributed this observation to the different concentration of graphene flakes for this sample, resulting in a lower platinum nanoparticle/graphene ratio. Nevertheless, both samples are characterized by a rather negligible aggregation of nanoparticles, proving that the graphene–PCA adduct acts as a scaffold for the arrangement of the particles on graphene, preventing the typical coalescence and precipitation issues.


Uniform Functionalization of High-Quality Graphene with Platinum Nanoparticles for Electrocatalytic Water Reduction.

Mazzaro R, Boni A, Valenti G, Marcaccio M, Paolucci F, Ortolani L, Morandi V, Ceroni P, Bergamini G - ChemistryOpen (2015)

Comparison between decoration of exfoliated graphene produced with different techniques: PCA-G using 1-pyrenecarboxylic acid (PCA) (left) and NMP-G using 1-methyl-2-pyrrolidone (NMP) (right). a,b) Low-magnification scanning transmission electron microscope (STEM) micrographs of decorated graphene flakes. c,d) High-resolution transmission electron microscopy (HR-TEM) micrographs of flake edges covered by platinum nanoparticles. e,f) Size distribution histogram of the platinum nanoparticles synthesized on graphene. The distribution was fitted by using the Lorentz function, and the average diameter is reported in the inset.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4522175&req=5

fig02: Comparison between decoration of exfoliated graphene produced with different techniques: PCA-G using 1-pyrenecarboxylic acid (PCA) (left) and NMP-G using 1-methyl-2-pyrrolidone (NMP) (right). a,b) Low-magnification scanning transmission electron microscope (STEM) micrographs of decorated graphene flakes. c,d) High-resolution transmission electron microscopy (HR-TEM) micrographs of flake edges covered by platinum nanoparticles. e,f) Size distribution histogram of the platinum nanoparticles synthesized on graphene. The distribution was fitted by using the Lorentz function, and the average diameter is reported in the inset.
Mentions: Figure 2 shows the comparison between the results of the platinum nanoparticle decoration of exfoliated graphene using the PCA-G and NMP-G methods. The scanning transmission electron microscope (STEM) and HR-TEM micrographs (Figure 2 a–d) clearly show the strong selectivity of the decoration, without any particles outside the platelets, with a slightly lower concentration of particles in the NMP-G sample. We attributed this observation to the different concentration of graphene flakes for this sample, resulting in a lower platinum nanoparticle/graphene ratio. Nevertheless, both samples are characterized by a rather negligible aggregation of nanoparticles, proving that the graphene–PCA adduct acts as a scaffold for the arrangement of the particles on graphene, preventing the typical coalescence and precipitation issues.

Bottom Line: The turnover frequency at zero overpotential (TOF0 in 0.1 m phosphate buffer, pH 6.8) was determined to be approximately 4600 h(-1).This remarkably high value is likely due to the optimal dispersion of the platinum nanoparticles on the graphene substrate, which enables the material to be loaded with only very small amounts of the noble metal (i.e., Pt) despite the very highly active surface.This study provides a new outlook on the design of novel materials for the development of robust and scalable water-splitting devices.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Chimica "G. Ciamician", Università di Bologna Via Selmi 2, 40126, Bologna, Italy ; Institute for Microelectronics & Microsystems (IMM)-Bologna, National Research Council (CNR) Via Gobetti 101, 40129, Bologna, Italy.

ABSTRACT
Graphene-metal composites have potential as novel catalysts due to their unique electrical properties. Here, we report the synthesis of a composite material comprised of monodispersed platinum nanoparticles on high-quality graphene obtained by using two different exfoliation techniques. The material, prepared via an easy, low-cost and reproducible procedure, was evaluated as an electrocatalyst for the hydrogen evolution reaction. The turnover frequency at zero overpotential (TOF0 in 0.1 m phosphate buffer, pH 6.8) was determined to be approximately 4600 h(-1). This remarkably high value is likely due to the optimal dispersion of the platinum nanoparticles on the graphene substrate, which enables the material to be loaded with only very small amounts of the noble metal (i.e., Pt) despite the very highly active surface. This study provides a new outlook on the design of novel materials for the development of robust and scalable water-splitting devices.

No MeSH data available.


Related in: MedlinePlus