Coral-Shaped MoS₂ Decorated with Graphene Quantum Dots Performing as a Highly Active Electrocatalyst for Hydrogen Evolution Reaction

Abstract

We report a new CVD method to prepare coral-shaped monolayer MoS with a large amount of exposed edge sites for catalyzing hydrogen evolution reaction. The electrocatalytic activities of the coral-shaped MoS can be further enhanced by electronic band engineering via decorated with graphene quantum dot (GQD) decoration. Generally, GQDs improve the electrical conductivity of the MoS electrocatalyst. First-principles calculations suggest that the coral MoS@GQD is a zero-gap material. The high electric conductivity and pronounced catalytically active sites give the hybrid catalyst outstanding electrocatalytic performance with a small onset overpotential of 95 mV and a low Tafel slope of 40 mV/dec as well as excellent long-term electrocatalytic stability. The present work provides a potential way to design two-dimensional hydrogen evolution reaction (HER) electrocatalysts through controlling the shape and modulating the electric conductivity.

Defects Enhance the Electrocatalytic Hydrogen Evolution Properties of MoS2‐based Materials

“…Defect engineering can tune the surface electron state to improve the conductivity of the carbon support further. [41,42] Therefore, electron transfer can be accelerated through the synergy between MoS 2 and defective conductive substrate, thereby improving electrocatalytic performance. The defective conductive carbon supports can also increase the concentration of active edge sites in the basal plane of MoS 2 by altering its morphology.…”

Hybridizing Strong Quadrupole Gap Plasmons Using Optimized Nanoantennas with Bilayer MoS2 for Excellent Photo‐Electrochemical Hydrogen Evolution

“…The results in Figure S14a in the Supporting Information reveal the effectively modified band structure by compounding the Au and MoS 2 . The band gap of MoS 2 @Au reduces almost to zero, leading to easier and faster electronic transportation . In addition, from Figure S14b in the Supporting Information, we can clearly see the Fermi level of MoS 2 @Au shifts toward conduction band with new isolated energy level formed in the band gap.…”

Bottom‐Up Synthesized MoS2 Interfacing Polymer Carbon Nanodots with Electrocatalytic Activity for Hydrogen Evolution

“…However, the preparation of the aforementioned TMD/PCND hybrid materials was achieved by top‐down strategies based on exfoliation of MoS 2 (or WS 2 ) followed by functionalization and coupling with PCNDs. On the contrary, bottom‐up approaches for TMDs remain rather unexplored, and in the cases in which they have been employed the conjugated carbon nanodots were prepared from carbonaceous or graphitic sources. Hydrothermal treatment of carbonaceous CNDs, Na 2 MoO 4 , and l ‐cysteine resulted in the formation of MoS 2 ‐CND .…”

“…Hydrothermal treatment of carbonaceous CNDs, Na 2 MoO 4 , and l ‐cysteine resulted in the formation of MoS 2 ‐CND . Meanwhile, another electrocatalyst has been prepared by drop casting GCNDs onto MoS 2 grown by chemical vapor deposition . Moreover, by employing the latter preparation process, MoS 2 ‐GCND was obtained, and charge transfer between the two components was studied …”