Ultrafine Ruthenium Oxide Nanoparticles Supported on Molybdenum Oxide Nanosheets as Highly Efficient Electrocatalyst for Hydrogen Evolution in Acidic Medium

Abstract

Engineering of efficient, robust and inexpensive Pt-free catalysts for the hydrogen evolution reaction has drawn great attention, and there is a rapidly growing demand for electrochemical water-splitting reactions. Here, we report, for the first time, synthesis of ruthenium oxide nanoparticles supported on molybdenum oxide nanosheets (MoO 3 @RuO 2 ). This composite catalyst was prepared sonochemically, followed by calcination of the product in air at 400°C for one hour. The as-synthesized MoO 3 @RuO 2 composite catalyst was used to explore the electro-catalytic hydrogen evolution reaction in acidic medium.Notably, compared to MoO 3 or RuO 2 , the composite exhibited high exchange current density of 0.57 mA cm À 2 , and a current density of 10 mA cm À 2 was achieved at low overpotential of 110 mV in 0.5 M H 2 SO 4 . The Tafel slope of the MoO 3 @RuO 2 catalyst was 62 mV dec À 1 and it showed excellent stability. This remarkable performance can be attributed to the synergetic effect generated by the strong interaction between MoO 3 nanosheets and RuO 2 nanoparticles, which resulted in enhanced long-term stability as well.be a potential alternative in various energy conversion applications to the benchmark Pt catalyst, which is significantly more expensive than ruthenium metal.

Nanostructured MoO3 for Efficient Energy and Environmental Catalysis

“…The HER activity of MoO3/MoS2 remained stable even if it was tested for 10,000 cycles ( Figure 3c) [56]. Besides, Pt [59], Pd [60], RuO2 [19] can also load on MoO3, to get excellent electrocatalysts for electrocatalytic hydrogen evolution. [49].…”

“…Stability is another crucial factor for catalysts. In general, MoO 3 -based nanocatalysts, which served as substrate or active center, possessed excellent stability in both acid and alkaline media for HER [19,55]. The current density can remain stable at a specific voltage for 12 [55], 24 [19], and even 40 h [65].…”

“…Each oxygen atom bonds to only one molybdenum atom of MoO 6 octahedra, and oxygen vacancy generates Mo dangling bond. MoO 3 favors the adsorption of water molecules in oxygen vacancies, which act as electron acceptors and consequently reduce the energy barrier make it highly reactive for electrocatalysis [2,19]. As a good gasochromic material, MoO 3 has efficient positive-ion accommodation and good charge transfer, and it can be used as an optical-based gas sensor.…”

Ecofriendly ruthenium-containing nanomaterials: synthesis, characterization, electrochemistry, bioactivity and catalysis

“…Reports suggest that metal NPs synthesized via the sol-gel technique are more active than those synthesized through the adsorption-reduction technique, as the former is capable of generating nanocatalysts of suitable particle size with high surface activity. 33 As depicted in Scheme 3, the structures can broadly be classied as monometallic or bimetallic NPs. Monometallic NPs can further be subdivided into catalytic and bioactive NMs, based on the presence or absence of substrate adsorption.…”

Surface and Interface Engineering: Molybdenum Carbide–Based Nanomaterials for Electrochemical Energy Conversion

“…Previous researches have revealed that charge transfer at the interfaces of hybrid plays a significant role in the catalytic enhancement for HER. [108][109][110] For instance, highly dispersed β-Mo 2 C nanoparticles with an average size of 5 nm embedded in ordered mesoporous carbon (OMC) composite has been synthesized via the pyrolysis of Mo salts and OMC precursors. [111] Figure 6a,b shows the highly ordered parallel mesoporous carbon channels with well-dispersed Mo 2 C nanoparticles loading.…”