Interface strain in vertically stacked two-dimensional heterostructured carbon-MoS2 nanosheets controls electrochemical reactivity

Abstract

Two-dimensional (2D) materials offer numerous advantages for electrochemical energy storage and conversion due to fast charge transfer kinetics, highly accessible surface area, and tunable electronic and optical properties. Stacking of 2D materials generates heterogeneous interfaces that can modify native chemical and physical material properties. Here, we demonstrate that local strain at a carbon-MoS2 interface in a vertically stacked 2D material directs the pathway for chemical storage in MoS2 on lithium metal insertion. With average measured MoS2 strain of ∼0.1% due to lattice mismatch between the carbon and MoS2 layers, lithium insertion is facilitated by an energy-efficient cation-exchange transformation. This is compared with low-voltage lithium intercalation for unstrained MoS2. This observation implies that mechanical properties of interfaces in heterogeneous 2D materials can be leveraged to direct energetics of chemical processes relevant to a wide range of applications such as electrochemical energy storage and conversion, catalysis and sensing.

Synergetic Exfoliation and Lateral Size Engineering of MoS2 for Enhanced Photocatalytic Hydrogen Generation

“…The spectrum indicates the presence of both terminal and bridging and apical S ligands in amorphous MoS x . For crystalline MoS 2 , only a single doublet was observed corresponding to S 2p 1/2 and S 2p 3/2 orbitals of divalent sulfide ions, which is in good agreement with the binding energy of S 2− ions in 2H‐MoS 2 . Moreover, Raman spectroscopy (Figure S2, Supporting Information) further confirmed the 2H‐phase structure of the as‐prepared MoS 2 precursor by the appearance of two distinct peaks at 380 and 406 cm −1 , which correspond to the in‐plane vibration ( E 2g 1 ) and out‐of‐plane mode ( A 1g ), respectively .…”

A simple electrochemical route to metallic phase trilayer MoS2: evaluation as electrocatalysts and supercapacitors

“…When the potential of the electrode was scanned in a negative direction, a cathodic current started to flow at approximately −3.0 V vs. Ag wire, and a broad peak was observed between -4.5 to −5.0 V. This process was due to the insertion of Li + into the MoS 2 . 23,24 In the return sweep, a broad anodic peak was seen at 1.0 V due to the de-intercalation of Li + (Equation 1). The shape of the CV reported here is similar to that reported in the literature except that the peak-to-peak separation of the Li + intercalation and de-intercalation is wider.…”

MoS2‐on‐MXene Heterostructures as Highly Reversible Anode Materials for Lithium‐Ion Batteries

“…In fact, during the conversion from Li x MoS 2 to Li 2 S, several intermediate polysulfides will form . Similar to Li‐sulfur batteries, the polysulfide shuttling problem during discharge process may also occur .…”