Narrow‐Gap Quantum Wires Arising from the Edges of Monolayer MoS₂ Synthesized on Graphene

Abstract

MoS2/graphene (MoS2/Gr) vertical heterostructures have exhibited great application potentials in high speed electronic and optoelectronic devices, as well as efficient electrocatalysts in hydrogen evolution reaction (HER). The electronic property at the edge of monolayer MoS2 is an essential parameter for addressing such applications. Herein, it is reported that, for monolayer MoS2 synthesized on Gr/Au foils by chemical vapor deposition, a dramatic decrease of the bandgap from ≈2.20 to ≈0.30 eV occurs at the domain edge within a lateral distance of ≈6 nm, as evidenced by scanning tunneling microscopy/spectroscopy observations. The edges of monolayer MoS2 on Gr/Au foils can thus be regarded as narrow‐gap quantum wires considering of their reduced bandgaps. More intriguingly, it is found that this bandgap decrease at the domain edge is closely related to the rather high HER performance for MoS2/Gr/Au foils comparing with that of MoS2/Au foils. Briefly, this work should propel the band structure investigations for MoS2/Gr stacks and their applications in energy related fields.

2D Metallic Transitional Metal Dichalcogenides for Electrochemical Hydrogen Evolution

“…Synthesizing TMDCs on conductive substrates (such as Au foils, graphene, and glass carbon) has attracted more attention . The former two growth systems can be readily used for the onsite STM/STS characterizations of the atomic‐scale structures, defects, and the related electronic properties .…”

“…Synthesizing TMDCs on conductive substrates (such as Au foils, graphene, and glass carbon) has attracted more attention . The former two growth systems can be readily used for the onsite STM/STS characterizations of the atomic‐scale structures, defects, and the related electronic properties . The direct electrocatalytic and photocatalytic measurements can also be conducted on Au foils or glass carbon electrode materials, thus providing straight evidences for their applications in related fields.…”

Modulierung der elektronischen Strukturen anorganischer Nanomaterialien für eine effiziente elektrokatalytische Wasserspaltung

“…Einer detaillierten Analyse zufolge sind zueinander passende Elektronenaffinitäten und Fermi-Niveaus der Materialien die Voraussetzung fürd ie Konstruktion eines effizienten Mott-Schottky-Elektrokatalysators. [167,168] Vork urzem berichteten Yaoe tal. [164] Da die Elektronenaffinitätv on MoB im Va kuum grçßer war als die von g-C 3 N 4 ,k onnten Elektronen von g-C 3 N 4 auf MoB überwechseln, und das elektronenangereicherte MoB konnte so HER effizienter katalysieren.…”

“…[159,168,169] Statt der Herstellung gestapelter und verdichteter Heterostrukturen synthetisierten Fu et al beispielsweise eine 2D-In-Plane-WC/ Graphen-Heterostruktur.D iese bewirkte einen effizienteren Elektronentransfer zwischen Graphen und WC. [159,168,169] Statt der Herstellung gestapelter und verdichteter Heterostrukturen synthetisierten Fu et al beispielsweise eine 2D-In-Plane-WC/ Graphen-Heterostruktur.D iese bewirkte einen effizienteren Elektronentransfer zwischen Graphen und WC.…”

“…Inzwischen wurde ein Elektronen-Offset von ähnlicher Struktur auch durch andere Experimente und theoretische Arbeiten belegt. [167,168] Vork urzem berichteten Yaoe tal. über die Heterostruktur von gestçrtem Graphen (defective graphene,D G) und von NiFe-Doppelhydroxid-Nanoschichten (NiFeLDH-NS;L DH = layered double hydroxide).…”