Low voltage hydrogen plasma interaction with palladium surface

Radjabov, T.D.; Alimova, L. Ya.; Sharudo, A.V.

doi:10.1016/0022-3115(84)90560-9

Cited by 2 publications

(2 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although TEM imaging is not a surface characterization technique, the observed evolution of the image contrast upon plasma treatment provides some insight into nanoparticle surface restructuring. Specifically, the darker regions might stem from high diffraction angles which can be inferred from induced strain or defects on the surface, as reported, for example, for lattice dislocations and stacking faults. , This effect is particularly apparent after the H 2 plasma treatment step (Figure a, dashed-line highlighted region) and in line with earlier reports of plasma treatments structurally altering Pd surfaces at the atomic level. , Furthermore, atomic force microscopy (AFM) topographical scans of representative nanoparticles corroborate the surface structuring as a significant increase of surface roughness from 0.1 ± 0.0 nm on a pristine Pd nanoparticle to 0.8 ± 0.0 nm after H 2 plasma treatment (Figure . For additional sampling details refer to Figure S6 and Table S3).…”

Section: Resultssupporting

confidence: 86%

“…62,63 This effect is particularly apparent after the H 2 plasma treatment step (Figure 6a, dashed-line highlighted region) and in line with earlier reports of plasma treatments structurally altering Pd surfaces at the atomic level. 64,65 Furthermore, atomic force microscopy (AFM) topographical scans of representative nanoparticles corroborate the surface structuring as a significant increase of surface roughness from 0.1 ± 0.0 nm on a pristine Pd nanoparticle to 0.8 ± 0.0 nm after H 2 plasma treatment (Figure 7. For additional sampling details refer to Figure S6 and Table S3).…”

Section: ■ Results and Discussionmentioning

confidence: 72%

See 1 more Smart Citation

Plasma Cleaning of Cationic Surfactants from Pd Nanoparticle Surfaces: Implications for Hydrogen Sorption

Darmadi

Piella

Stolaś

et al. 2023

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

Cationic surfactants are widely used in the colloidal synthesis of noble metal nanoparticles in general, and of Pd nanoparticles in particular, to stabilize them toward aggregate formation in solution and to promote shape-specific particle growth. Despite the benefits at the synthesis stage, these surfactants can be problematic once the nanoparticles are to be applied as they may both geometrically block and electronically alter surface sites that are important for surface chemical reactions. This is particularly relevant in applications like bio- and chemosensors where analyte-nanoparticle surface interactions constitute the actual sensing event. Here, H2 sensors based on Pd and its alloys are no exception since the dissociation of H2 on the particle surface is the first step toward hydride formation and thus hydrogen detection, and it has been demonstrated that the presence of surfactant molecules detrimentally affects the hydrogen sorption rate. Here, we therefore develop a scheme to remove cationic surfactants from Pd nanoparticle surfaces by means of subsequent O2 and H2 plasma treatment, whose effectiveness we verify by X-ray photoelectron spectroscopy. Furthermore, we find that the plasma treatment both alters the surface structure of the Pd nanoparticles at the atomic level and leads to surface contamination by so-called H2 plasma swift chemical sputtering of Al, Si and F species present in the plasma chamber, which in combination significantly reduce hydrogen sorption rates and increase apparent activation energies, as revealed by plasmonic hydrogen sorption kinetic measurements. Finally, we show that both these effects can be reversed by mild thermal annealing and that after the complete plasma cleaning–thermal annealing sequence hydrogen sorption rates essentially identical to the ones of neat Pd particles never exposed to cationic surfactants can be achieved. This advertises tailored plasma cleaning and mild heat treatments as an effective recipe for the removal of surfactant molecules from nanoparticle surfaces.

show abstract