Atomically engineering activation sites onto metallic 1T-MoS2 catalysts for enhanced electrochemical hydrogen evolution

Abstract

Engineering catalytic sites at the atomic level provides an opportunity to understand the catalyst’s active sites, which is vital to the development of improved catalysts. Here we show a reliable and tunable polyoxometalate template-based synthetic strategy to atomically engineer metal doping sites onto metallic 1T-MoS 2 , using Anderson-type polyoxometalates as precursors. Benefiting from engineering nickel and oxygen atoms, the optimized electrocatalyst shows great enhancement in the hydrogen evolution reaction with a positive onset potential of ~ 0 V and a low overpotential of −46 mV in alkaline electrolyte, comparable to platinum-based catalysts. First-principles calculations reveal co-doping nickel and oxygen into 1T-MoS 2 assists the process of water dissociation and hydrogen generation from their intermediate states. This research will expand on the ability to improve the activities of various catalysts by precisely engineering atomic activation sites to achieve significant electronic modulations and improve atomic utilization efficiencies.

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

“…All above results suggest that Ru is single‐atomically anchored in the MoS 2 plane by replacing Mo sites and coordinating with S atoms. Moreover, we also further explored the interaction between Ru and MoS 2 substrate, and found the transition of MoS 2 from 2H to 1T phase when the Ru is doped into the MoS 2 matrix, which is consistent with the previous reference . Figure e shows visibly different structural regions in the SA‐Ru‐MoS 2 sample, where red and green balls indicate Mo and S atoms, respectively.…”

“…In alkaline condition, the HER reaction process include two steps: i) the initial H 2 O dissociation step (the Volmer step) and ii) the H 2 production step (the Tafel or Heyrovsky step). The results in previous literatures indicate that the free energy differences of the initial water dissociation step, , and the final adsorption and desorption of H* intermediate step, Δ G H* , are mainly responsible for the sluggish HER activity on the surface of MoS 2 . The free energy diagrams on the surfaces of eight model catalysts were shown in Figure a.…”

Theoretical Analysis of Surface Active Sites in Defective 2H and 1T′ MoS2 Polymorphs for Hydrogen Evolution Reaction: Quantifying the Total Activity of Point Defects

“…As a complementary study, we investigated the change in Δ G H on 2H and 1T′ MoS 2 surfaces exposed to uniaxial strain which can be present in folded MoS 2 sheets caused by impurities or defects, and that are commonly observed experimentally 6,11g,35a,35d. We noted that for both 2H and 1T′, a positive (tensile) strain strengthen the Δ G H while a negative strain weakens the Δ G H (Figures S9–S11, Supporting Information) as previously found for 2H MoS 2 4b.…”

Defect‐Rich Heterogeneous MoS2/NiS2 Nanosheets Electrocatalysts for Efficient Overall Water Splitting

“…[1] Electrocatalytic water splitting involving two half reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), requires highly efficient electrocatalysts such as Pt for HER and RuO 2 or IrO 2 for OER to lower the activation barrier and boost the reaction process. [1] Electrocatalytic water splitting involving two half reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), requires highly efficient electrocatalysts such as Pt for HER and RuO 2 or IrO 2 for OER to lower the activation barrier and boost the reaction process.…”

“…[7,8] However, the limited electroactive sites and insufficient stability of these TMSs seriously restricted the improved electrocatalytic activity. [1,7] Considering that surfaces or interfaces play the key role in electrochemical reactions, the morphology, surface defects or interfaces, and electrical structures are the key factors on the electrocatalytic performances of efficient catalysts. [1,7] Considering that surfaces or interfaces play the key role in electrochemical reactions, the morphology, surface defects or interfaces, and electrical structures are the key factors on the electrocatalytic performances of efficient catalysts.…”