Amorphous Ruthenium‐Sulfide with Isolated Catalytic Sites for Pt‐Like Electrocatalytic Hydrogen Production Over Whole pH Range

Abstract

Electrocatalytic hydrogen evolution reaction (HER) is an efficient way to generate hydrogen fuel for the storage of renewable energy. Currently, the widely used Pt‐based catalysts suffer from high costs and limited electrochemical stability; therefore, developing an efficient alternative catalyst is very urgent. Herein, one pot hydrothermal synthesis is reported of amorphous ruthenium‐sulfide (RuSx) nanoparticles (NPs) supported on sulfur‐doped graphene oxide (GO). The as‐obtained composite serves as a Pt‐like HER electrocatalyst. Achieving a current density of −10 mA cm−2 only requires a small overpotential (−31, −46, and −58 mV in acidic, neutral, and alkaline electrolyte, respectively) with high durability. The isolated Ru active site inducing Volmer–Heyrovsky mechanism in the RuSx NPs is demonstrated by the Tafel analysis and X‐ray absorption spectroscopy characterization. Theoretical simulation indicates the isolated Ru site exhibits Pt‐like Gibbs free energy of hydrogen adsorption (−0.21 eV) therefore generating high intrinsic HER activity. Moreover, the strong bonding between the RuSx and S–GO, as well as pH tolerance of RuSx are believed to contribute to the high stability. This work shows a new insight for amorphous materials and provides alternative opportunities in designing advanced electrocatalysts with low‐cost for HER in the hydrogen economy.

Ru‐Doping Enhanced Electrocatalysis of Metal–Organic Framework Nanosheets toward Overall Water Splitting

“…The HER in alkaline media involves two tandem steps, that is, the Volmer step to produce adsorbed H atom, which subsequently generates H 2 via either Heyrovsky or Tafel step [15] . Therefore this comparison unveils that Ru‐doping in MIL‐53(NiFe)@NF greatly accelerates the sluggish Volmer step to boost the HER [9b, 16] . Electrochemical impedance spectrum (EIS) measurements in Figure 2 d show that the charge‐transfer resistance of MIL‐53(Ru‐NiFe)@NF significantly decreases in comparison with MIL‐53(NiFe)@NF, which further confirms that the doped Ru atoms in MIL‐53(NiFe)@NF structure can essentially enhance the electron transport process at the electrode/electrolyte interface, in accordance with the LSV results in Figure 2 a.…”

Engineering Multimetallic Aerogels for pH‐Universal HER and ORR Electrocatalysis

“…Referring to reported electrochemical HER performances of noble‐metal‐NP‐based electrocatalysts, the as‐developed Au–Rh aerogel catalyst is among the most favorable ones with a high activity and fast kinetics (Figure 2j–l and Table S4, Supporting Information). [ 21–32 ] It is worth mentioning that, while quite a few noble‐metal‐based catalysts were investigated for HER across a wide range of pH values, only few can outperform commercial Pt/C in every environment. For example, ruthenium‐dots‐loaded self‐crosslinking carbon dots (Ru@SC‐CDs) performed slightly better than commercial Pt/C from the aspects of overpotential and exchange current density, while it is inferior to Pt/C in acid and neutral environment.…”

Ru Nanoparticles Supported on Co-Embedded N-Doped Carbon Nanotubes as Efficient Electrocatalysts for Hydrogen Evolution in Basic Media

“…The Tafel slope is extracted to investigate the reaction kinetics during HER[ Fig.3(C)], and it shows a similar order to the LSV results in this case. Especially, the slope of Ru/Co-NCNTs is about 36 mV/dec, which is less than that of 20% Pt/C(41 mV/dec), indicating that the HER pathway follows the Volmer-Tafel mechanism [21] . Mass activities of the samples were calculated with respect to their mass loading of total metal.…”