posted on 2019-10-17, 17:36authored byYuanli Li, Wanlin Zhou, Xu Zhao, Weiren Cheng, Hui Su, Hui Zhang, Meihuan Liu, Qinghua Liu
Rationally
architectural design and accessible construction of an efficient electrocatalyst
featuring with high activity and stability in acid solution are fundamentally
important to advance the renewable energy conversion technologies
nowadays. Herein, we deliberately conceive and successfully synthesize
a donutlike architecture of RuCu bimetallic nanoalloy with well-defined
nanoscale shell by a facile “galvanic replacement” strategy
to boost Ru-based electrocatalysts with prominent water oxidation
performance in an acid condition. The as-prepared donutlike RuCu nanostructures
with an ultrathin shell of ∼1 nm thickness could catalyze the
oxygen evolution reaction (OER) under a small overpotential of 270
mV at 10 mA·cm–2 with excellent long-term stability
and ultrahigh mass activity of ∼1000 A·gRu–1, two-orders of magnitude larger than Ru and commercial
RuO2 nanoparticles. Experimental and theoretical analyses
reveal that the well-dispersed Cu element plays a key role in the
architectural engineering and catalytic activity improvement of donutlike
RuCu nanoalloy catalysts via dual regulation of coordination environment
and electron structure of Ru active sites. Especially, by the merits
of ultrathin shell structure, the strong surface electron transfer
via robust Ru–Cu bonds could effectively promote the appearance
of active and stable Ru2+ throughout donutlike RuCu nanoalloy,
resulting in much more thermodynamically favor for H2O
adsorption and *OOH formation during OER process compared with metallic
Ru nanoparticle. Undoubtedly, this approach may open a new avenue
for strategically designing highly active and performance-oriented
electrocatalytic materials for tremendous energy applications.