Ruthenium‐Doped Cobalt–Chromium Layered Double Hydroxides for Enhancing Oxygen Evolution through Regulating Charge Transfer

Abstract

Exploring the origin of transition metal (TM) lattice‐doped layered double hydroxides (LDHs) toward the oxygen evolution reaction (OER) plays a crucial role in engineering efficient electrocatalysts. Without understanding the physics behind the TM‐induced catalytic enhancements, it would be challenging to design the next generation of electrocatalysts. Herein, single Ru atoms are introduced into a CoCr LDHs lattice to improve activity. In 0.1 m KOH, CoCrRu LDHs require only 290 mV overpotential to drive to 10 mA cm−2 and show a Tafel slope of 56.12 mV dec−1. Electronic structure analyses based on density functional theory confirm that promoted OER activity originates from synergetic charge transfer among Ru, Cr, and Co elements. Specifically, Ru dopants can downshift d states of Co and enhance electron donation of Cr to oxygenates, which essentially breaks the scaling relation and achieves higher activity. This work provides insights into how single atomic Ru dopant tunes the electronic structures of its neighbor's active site Co and thus increases OER activities.

Engineering Self‐Reconstruction via Flexible Components in Layered Double Hydroxides for Superior‐Evolving Performance

“…[23] Their corresponding selected area electron diffraction (SAED) images (Figure S1a,b, Supporting Information) show similar diffraction rings from (012), (015), and (006) planes of edge-sharing MO 6 octahedron layer in LDHs structure. [40] Their LDH crystal structures are further determined by the powder X-ray diffraction (XRD) patterns (Figure 2e), which correspond to the standard PDF no. 40-0215, [41] where the more negative (003) peak of NiFeMo-LDH indicates an expansion of interlayer distance compared to typical NiFeC-LDH, conductive to electrolyte penetration for deep reconstruction and active site exposure.…”

Amorphous CoOx-Decorated Crystalline RuO2 Nanosheets as Bifunctional Catalysts for Boosting Overall Water Splitting at Large Current Density

“…39 Obviously, the C dl of CoO x −RuO 2 /NF, RuO 2 / NF, CoO x /NF, and NF are 1.26, 0.56, 0.36, and 0.07 mF, respectively. This result reveals that the decoration of CoO x to RuO 2 can create more active sites, 40 which is critical to boost catalytic activity. The OER and HER polarization curves after normalization is shown in Figure S8 according to eq 2 41…”

Synthesis of a magnetically separable LDH-based S-scheme nano-heterojunction for the activation of peroxymonosulfate towards the efficient visible-light photodegradation of diethyl phthalate

“…On the other hand, the attendance of Cr 3+ was studied through the ascribed fine spectra Cr 2p. The peaks settled at 577.38 affirmed Cr 2P 3/2 state; whereas, the Cr 2p 1/2 state was confirmed with the appeared peak at 587.1 eV [36,37]. Lastly, the recorded high-resolution Fe 2p spectrum implied the presence of Fe 2+ and Fe 3+ on the surface of the sample by observing two main peaks with their 15 satellite peaks located at the binding energy of 705-735 [38].…”