Single‐Atom Ru Doping Induced Phase Transition of MoS₂ and S Vacancy for Hydrogen Evolution Reaction

Abstract

Using electrochemical water splitting to produce hydrogen is still a grand challenge due to the lack of economical and efficient Pt‐free catalysts. Herein, a single‐atom Ru supported on MoS2 (SA‐Ru‐MoS2) electrocatalyst for the hydrogen evolution reaction (HER) is reported. Results indicate that single‐atom Ru doping induces phase transition of MoS2 and generation of S vacancies, which significantly improve the performance of inert 2D MoS2 for HER. In particular, the SA‐Ru‐MoS2 electrocatalyst exhibits a low overpotential of 76 mV at 10 mA cm−2 in alkaline media, which is superior to most electrocatalysts previously reported in the literature. Combining experimental results with density functional theory (DFT) calculations, it is further revealed that the origin of high HER activity is mainly attributed to the synergy effects of single‐atom Ru doping and S vacancies and phase transition of local structure of MoS2, which efficiently tailors the electronic structure of SA‐Ru‐MoS2 and extremely reduces the energy barrier of the Volmer step and the adsorption/desorption of H* intermediate step. In short, this work provides a single‐atom doping strategy to transfer the inert MoS2 into the highly efficient electrocatalysts.

Microenvironment modulation of single-atom catalysts and their roles in electrochemical energy conversion

“…The HER activity could be improved by designing large numbers of well-defined atomically dispersed active sites hosted over transition metal dichalcogenide materials, such as MoS 2 (111)(112)(113)(114)(115). For instance, carbonized polyacrylonitrile-immobilized single molecular MoS 2 (MoS 2 -cPAN) was demonstrated with much higher turnsover frequency (TOF) to HER than bulk MoS 2 (Fig.…”

Recent advances in single metal atom-doped MoS2 as catalysts for hydrogen evolution reaction

“…Here, different synthetic strategies for single metal atom-doped MoS 2 are summarized and discussed ( Fig. 2a-f [36][37][38][39][40][41]).…”

“…Recently, this method has been applied in the preparation of several SA-doped MoS 2 catalysts. For example, Zhang et al [36] reported an SA-Ru doped MoS 2 electrocatalyst that was formed using a one-step impregnation method. As shown in Fig.…”

“…[41]. Copyright 2019 ACS the lattices of MoS 2 for HER application and showed an enhanced performance, including Pd [57], Rh [59] and Ru [36].…”

Defect Engineering of van der Waals Solids for Electrocatalytic Hydrogen Evolution

“…By theoretical calculations, it revealed that the doped Pt atoms can increase the electronic states around the Fermi level, thus tuning the ΔG H* of S atoms neighboring the doped Pt to favor the HER activity. In addition, Zhang et al [23] synthesized singleatom Ru-doped MoS 2 (SA-Ru-MoS 2 ). It induced phase transition from 2H-MoS 2 to 1T-MoS 2 and generated S vacancies, resulting a low η of 76 mV at 10 mA cm À 2 in alkaline media, as shown in Figure 3a and b.…”