Energy Level Engineering of MoS₂ by Transition-Metal Doping for Accelerating Hydrogen Evolution Reaction

Abstract

Water-splitting devices for hydrogen generation through electrolysis (hydrogen evolution reaction, HER) hold great promise for clean energy. However, their practical application relies on the development of inexpensive and efficient catalysts to replace precious platinum catalysts. We previously reported that HER can be largely enhanced through finely tuning the energy level of molybdenum sulfide (MoS) by hot electron injection from plasmonic gold nanoparticles. Under this inspiration, herein, we propose a strategy to improve the HER performance of MoS by engineering its energy level via direct transition-metal doping. We find that zinc-doped MoS (Zn-MoS) exhibits superior electrochemical activity toward HER as evidenced by the positively shifted onset potential to -0.13 V vs RHE. A turnover of 15.44 s at 300 mV overpotential is achieved, which by far exceeds the activity of MoS catalysts reported. The large enhancement can be attributed to the synergistic effect of electronic effect (energy level matching) and morphological effect (rich active sites) via thermodynamic and kinetic acceleration, respectively. This design opens up further opportunities for improving electrocatalysts by incorporating promoters, which broadens the understanding toward the optimization of electrocatalytic activity of these unique materials.

Stimulated Electrocatalytic Hydrogen Evolution Activity of MOF‐Derived MoS2 Basal Domains via Charge Injection through Surface Functionalization and Heteroatom Doping

“…As presented in Figure 4a, MoS-CoS-Zn exhibits a valence band maximum value of 0.48 eV, which is much closer to the Fermi level (set to 0 eV) than 0.80 eV obtained for MoS-CoS. [38] Compared with MoS-CoS, lower energy is required to liberate the electrons from MoS-CoS-Zn, which, from the thermodynamic viewpoint, supports the lower overpotential requirement of the zinc-coordinated structures. Furthermore, work function of MoS-CoS is found to be 5.15 eV and decreased by 0.35 eV upon insertion of zinc to 4.8 eV (Figure 4b).…”

Beyond 1T‐phase? Synergistic Electronic Structure and Defects Engineering in 2H‐MoS2xSe2(1‐x) Nanosheets for Enhanced Hydrogen Evolution Reaction and Sodium Storage

“…For 1T‐MoSe 2 , the computed density of states (DOS) is consecutive around the Fermi level, suggesting the conductive nature of 1T‐phase structure, which is also well consistent with the recent results . In addition, the chemisorbed hydrogen is considered as the reaction intermediate for HER and the ΔG H* is the factor determining the HER activity . Generally, an excellent HER catalyst should show a ΔG H* closer to 0 eV .…”

Reversing Interfacial Catalysis of Ambipolar WSe2 Single Crystal

“…Figure 3b shows the Tafel curves which are fitted according to Tafel equation: η = b log(j) + a, where η is the potential, b is the Tafel slope, and j is current density, respectively. Although the external field modulation may not lead to the highest catalytic performance, combination with other strategies, e.g., introducing point defects via doping heteroatoms [28,29] may further enhance the catalytic performance. As seen, the polarization current is largely boosted with the increasing of gate voltage from 0 to +20 V. voltages are +5, +10, +15, and +20 V, respectively.…”

“…2020, 7,1901382 Interestingly, the position of the adsorbed H with respect to the Se atom depends on its charge state. [28,29] Generally, a good HER catalyst should feature | | H * ∆G value near zero, which allows optimal adsorption/desorption kinetics. The SeH bond is aligned with a WSe bond, pointing toward the surface spacing.…”