A Novel Heterostructure Based on RuMo Nanoalloys and N‐doped Carbon as an Efficient Electrocatalyst for the Hydrogen Evolution Reaction

Abstract

Heterostructures, [1] particularly 2D heterostructures, have shown great potential in the field of catalytic energy conversion due to the fascinating synergism of different components in tuning electronic structures for promoted surface catalysis. [2-5] In typical catalytic reactions, heterostructures always need to be exposed to corrosive liquids and gases to fully interact with the reactants. Therefore, the rational design and synthesis of heterostructures that have rich exposed active sites and highly stable heterointerfaces are rising as an appealing and critical issue in the area of energy conversion. On the other hand, hydrogen generated from electrochemical water splitting is regarded as an ideal alternative to fossil fuels because of its ultrahigh gravimetric energy density, zero-carbon emission, and natural abundance. [6-10] Currently, the alkaline electrolyzers are technically more available for the production of electrocatalytic hydrogen, such as in the water-alkaline electrolysis and in the chloralkaline industry, owing Heterostructures exhibit considerable potential in the field of energy conversion due to their excellent interfacial charge states in tuning the electronic properties of different components to promote catalytic activity. However, the rational preparation of heterostructures with highly active heterosurfaces remains a challenge because of the difficulty in component tuning, morphology control, and active site determination. Herein, a novel heterostructure based on a combination of RuMo nanoalloys and hexagonal N-doped carbon nanosheets is designed and synthesized. In this protocol, metal-containing anions and layered double hydroxides are employed to control the components and morphology of heterostructures, respectively. Accordingly, the as-made RuMo-nanoalloysembedded hexagonal porous carbon nanosheets are promising for the hydrogen evolution reaction (HER), resulting in an extremely small overpotential (18 mV), an ultralow Tafel slope (25 mV dec −1), and a high turnover frequency (3.57 H 2 s −1) in alkaline media, outperforming current Ru-based electrocatalysts. Firstprinciple calculations based on typical 2D N-doped carbon/RuMo nanoalloys heterostructures demonstrate that introducing N and Mo atoms into C and Ru lattices, respectively, triggers electron accumulation/depletion regions at the heterosurface and consequently reduces the energy barrier for the HER. This work presents a convenient method for rational fabrication of carbon-metal heterostructures for highly efficient electrocatalysis.

A Two‐dimensional Amorphous Plasmonic Heterostructure of Pd/MoO3‐x for Enhanced Photoelectrochemical Water Splitting Performance

“…The predominant peaks at approximately 2.4 and 3.0 Å for Mo foil EXAFS curve are assigned to Mo−Mo bonding. And the EXAFS curve of MoO 3‐x is characterized by three distinct peaks: two peaks at 1.2 and 1.6 Å corresponding to the chemical bonds of the Mo=O and Mo−O split in the MoO 6 octahedra, and the other one at 3.0 Å associated with Mo−Mo bonds [19] . The low intensities of 1.6 Å peaks indicate the structural disorder and the missing oxygen coordination in the MoO 3‐x, therewith resulting in formation of Mo−Mo bonds [7b] .…”

Engineering Ruthenium-Based Electrocatalysts for Effective Hydrogen Evolution Reaction

“…2 Effect of different doping strategies on free energy of reaction intermediates: a ΔG H* on Ru, P1-Ru, P2-Ru, and P3-Ru [31], with permission from the American Chemical Society. b Initial, intermediate, and final transition state free energy of Ru NCs/BNC and Pt/C in HER [33], with permission from the Elsevier Ltd. c Free energy of each reaction stage of RuMo alloying [47], with permission from the Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. d ΔG H* value under Co-doped Ru-based catalyst [41], with permission from the Nature Publishing Group showed outstanding electrocatalytic performance, such as small overpotential at 10 and 50 mA cm −2 (14 and 50 mV, respectively), superior durability in both electrolytes, and a low Tafel slope (28.9 mV dec −1 ).…”

“…Heterostructures showed great potential in the field of catalytic energy conversion because of the fascinating synergism of different components in tuning electronic structures for promoted surface catalysis, and the interface charge distribution can also be realized by adjusting different components [44][45][46]. Zhuang et al [47] devised a facile and scalable fabrication of a novel heterostructure RuMo nanoalloy-embedded 2D porous carbon (2DPC-RuMo) nanosheet with hard-templating synthesis and anion-exchange processes. The unique structures of the 2DPC-RuMo nanosheets obtained by alloying Mo atoms into the Ru lattice led to an excellent electrocatalytic HER activity with an extremely low overpotential (18 mV at 10 mA cm −2 in1 M KOH), an ultrasmall Tafel slope (25 mV dec −1 ), and a high turnover frequency (TOF) of 3.57 H 2 s −1 at 50 mV.…”

Kinetically Controlled, Scalable Synthesis of γ‐FeOOH Nanosheet Arrays on Nickel Foam toward Efficient Oxygen Evolution: The Key Role of In‐Situ‐Generated γ‐NiOOH

“…Compared with γ‐FeOOH@γ‐NiOOH, the positive shift of Fe 2p 3/2 peak in γ‐FeOOH/CC and negative shift of Ni 2p 3/2 peak in bare NF suggest an internal charge transfer from γ‐NiOOH to γ‐FeOOH in the heterostructure (Figure S22, Supporting Information). [ 24 ]…”