Hyper crosslinked polymer supported NHC stabilized gold nanoparticles with excellent catalytic performance in flow processes

Eisen, Constantin; Ge, Lingcong; Santini, Elena; Chin, Jia Min; Woodward, Robert T.; Reithofer, Michael R.

doi:10.1039/d2na00799a

“…A variety of techniques, including wet chemistry, electro-plating, sonochemistry, and dewetting, have been employed by researchers to alter or coat the surface of polymers with metal nanoparticles [10][11][12][13]. Recently, nanosized patterns with enhanced structural stability were produced on gold surfaces using reversible addition-fragmentation chain transfer (RAFT) PS [14].…”

Section: Introductionmentioning

confidence: 99%

Plasma Treatment of Polystyrene Films—Effect on Wettability and Surface Interactions with Au Nanoparticles

Islam¹,

Matouk

²

,

Ouldhamadouche

³

et al. 2023

Plasma

4

0

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Polystyrene (PS)/Gold (Au) is used for a wide range of applications, including composite nanofibers, catalysis, organic memory devices, and biosensing. In this work, PS films were deposited on silicon substrates via a spin coating technique followed by treatment with argon (Ar) plasma admixed with ammonia (NH3), oxygen (O2), or tetrafluoroethane (C2H2F4). X-Ray photoelectron spectroscopy (XPS) analysis revealed modified surface chemistry for Ar/O2, Ar/NH3, or Ar/C2H2F4 plasma treatment through the incorporation of oxygen, nitrogen, or fluorine groups, respectively. Size-controlled magnetron sputter deposition of Au nanoparticles (NP) onto these plasma-treated PS films was investigated via XPS and AFM techniques. The interaction of the Au NPs, as probed from the XPS and AFM measurements, is discussed by referring to changes in surface chemistry and morphology of the PS after plasma treatment. The results demonstrate the effect of surface chemistry on the interaction of Au NPs with polymer support having different surface functionalities. The XPS results show that significant oxygen surface incorporation resulted from oxygen-containing species in the plasma itself. The surface concentration of O increased from 0.4% for the pristine PS to 4.5 at%, 35.4 at%, and 45.6 at% for the Ar/C2H4F4, Ar/NH3, and Ar/O2, respectively. The water contact angle (WCA) values were noticed to decrease from 98° for the untreated PS to 95°, 37°, and 15° for Ar/C2H2F4, Ar/NH3, and Ar/O2 plasma-modified PS samples, respectively. AFM results demonstrate that surface treatment was also accompanied by surface morphology change. Small Au islands are well dispersed and cover the surface, thus forming a homogeneous, isotropic structure. The reported results are important for exploiting Au NPs use in catalysis and sensing applications.

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Poly(N‐Heterocyclic Carbene)‐Capped Alloy and Core‐Shell AuAg Bimetallic Nanoparticles

Nguyen,

Salek,

Shultz‐Johnson

et al. 2024

Angewandte Chemie

0

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N‐Heterocyclic carbene (NHC)‐stabilized metal nanoparticles (NPs) have recently attracted considerable attention. While most efforts in the field have been devoted to the development of NHC‐tethered monometallic NPs and enhancing their stabilities under various conditions, their bimetallic counterparts are rare in the literature. Herein, we demonstrate that the covalent immobilization of Au and Ag atoms on polymerized NHCs is a powerful method to access bimetallic AuAg NPs. In addition, we show that while AuAg alloy NPs are often obtained via this method, the use of bimetallic polymeric substrates with lower Ag content, relative to Au, results in the formation of core‐shell NPs with Au core and Ag shell. Application of these nanomaterials for oxygen reduction reaction is demonstrated with all materials exhibiting electrocatalytic activity. This work demonstrates for the first time that while bimetallic poly(NHC‐metal)s are viable substrates to access NHC‐stabilized bimetallic NPs, careful adjustment of metal content in the polymeric substrates can finetune the microstructure of the resulting NPs, i.e. alloy vs. core‐shell.

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Poly(N‐Heterocyclic Carbene)‐Capped Alloy and Core‐Shell AuAg Bimetallic Nanoparticles

Nguyen,

Salek,

Shultz‐Johnson

et al. 2024

Angew Chem Int Ed

0

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N‐Heterocyclic carbene (NHC)‐stabilized metal nanoparticles (NPs) have recently attracted considerable attention. While most efforts in the field have been devoted to the development of NHC‐tethered monometallic NPs and enhancing their stabilities under various conditions, their bimetallic counterparts are rare in the literature. Herein, we demonstrate that the covalent immobilization of Au and Ag atoms on polymerized NHCs is a powerful method to access bimetallic AuAg NPs. In addition, we show that while AuAg alloy NPs are often obtained via this method, the use of bimetallic polymeric substrates with lower Ag content, relative to Au, results in the formation of core‐shell NPs with Au core and Ag shell. Application of these nanomaterials for oxygen reduction reaction is demonstrated with all materials exhibiting electrocatalytic activity. This work demonstrates for the first time that while bimetallic poly(NHC‐metal)s are viable substrates to access NHC‐stabilized bimetallic NPs, careful adjustment of metal content in the polymeric substrates can finetune the microstructure of the resulting NPs, i.e. alloy vs. core‐shell.

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Hyper crosslinked polymer supported NHC stabilized gold nanoparticles with excellent catalytic performance in flow processes

Abstract: Highly active and selective heterogeneous catalysis driven by metallic nanoparticles relies on a high degree of stabilization of such nanomaterials facilitated by strong surface ligands or the deposition on solid...

Cited by 7 publications

References 62 publications

Plasma Treatment of Polystyrene Films—Effect on Wettability and Surface Interactions with Au Nanoparticles

Plasma Treatment of Polystyrene Films—Effect on Wettability and Surface Interactions with Au Nanoparticles

Poly(N‐Heterocyclic Carbene)‐Capped Alloy and Core‐Shell AuAg Bimetallic Nanoparticles

Poly(N‐Heterocyclic Carbene)‐Capped Alloy and Core‐Shell AuAg Bimetallic Nanoparticles

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