Details

Autor(en) / Beteiligte

• Moon, Sinyoung
• Cho, Yun-Bin
• Yu, Areum
• Kim, Myung Hwa
• Lee, Chongmok
• Lee, Youngmi

Titel

Single-Step Electrospun Ir/IrO2 Nanofibrous Structures Decorated with Au Nanoparticles for Highly Catalytic Oxygen Evolution Reaction

Ist Teil von

• ACS applied materials & interfaces, 2019-01, Vol.11 (2), p.1979-1987

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Nanocomposites of gold (Au) and iridium (Ir) oxide with various compositions (denoted as Au x Ir1–x O y , x = 0.05, 0.10, or 0.33, Au precursor molar ratio to Ir precursor) were synthesized via electrospinning and subsequent calcination method with two different solvent composition ratios of ethanol to N,N-dimethylformamide (DMF) in the electrospinning solution (ethanol/DMF = 70:30 or 50:50% v/v). Simple single-step electrospinning successfully fabricated a hierarchical nanostructure having Au nanoparticles formed on fibrous main frames of Ir/IrO2. Different solvent composition in the electrospinning solution induced the formation of main frames with distinct nanostructures; nanoribbons (Au x Ir1–x O y -70) with ethanol/DMF = 70:30; and nanofibers (Au x Ir1–x O y -50) with ethanol/DMF = 50:50. The pure Ir or Au counterparts (IrO y and Au) were also prepared by the same synthetic procedure as Au x Ir1–x O y . Oxygen evolution reaction (OER) activities of as-synthesized Au x Ir1–x O y were investigated in 0.5 M H2SO4 and compared to those of IrO y , Au, and commercial iridium (Ir/C, 20% Ir loading on Vulcan carbon). Among them, Au0.10Ir0.90O y -50 exhibited the best OER activity, even better than previously reported catalysts containing both Ir and Au. The high OER activity of Au0.10Ir0.90O y -50 was mainly attributed to the fiber frame structure and the optimal interfacial areas between Au and Ir/IrO2, which are electrophilic OER active sites. The stability of Au0.10Ir0.90O y -50 was also evaluated to be much higher than that of Ir/C during OER. The current study suggests that the presence of Au on the Ir/IrO2 surface improves the OER activity of Ir/IrO2.