Synthesis and Photoluminescence Properties of MoS₂/Graphene Heterostructure by Liquid-Phase Exfoliation

Abstract

Here, we report the synthesis of MoS 2 /graphene heterostructure in single-stage, liquid-phase exfoliation using a 7:3 isopropyl alcohol/water mixture. Further, the synthesized heterostructure was characterized using UV–visible and micro-Raman spectroscopies, transmission electron microscopy (TEM), and dynamic light scattering (DLS) analysis. UV–visible and micro-Raman analyses confirmed that the synthesized heterostructure had mostly few-layered (two-to-four sheets) MoS 2 . The photophysical properties of the heterostructure were analyzed using steady-state and time-resolved luminescence techniques. Enhanced photoluminescence was observed in the case of the heterostructure probably due to an increase in the defect sites or reduction in the rate of nonradiative decay upon formation of the sandwiched heterostructure. Applications of this heterostructure for fluorescence live-cell imaging were carried out, and the heterostructure demonstrated a better luminescence contrast compared to its individual counterpart MoS 2 in phosphate-buffered saline (PBS).

Improved liquid phase exfoliation technique for the fabrication of MoS2/graphene heterostructure-based photodetector

“…This peak C is frequently attributed to the π-π* absorption band of graphene and π-plasmon resonance band which emerges from a combined oscillation of π-electrons in the graphene lattice in riposte to incident light. The UV band at 272 nm makes it obvious that the graphene sample is composed of both thick multilayered and thin layered graphene [ 54 ]. The absorption spectra of MoS 2 /graphene heterostructures prepared in this work have shown comparable absorption bands at 685 and 624 nm identical to those of exfoliated MoS 2 [ 51 , 54 , 55 ].…”

“…The UV band at 272 nm makes it obvious that the graphene sample is composed of both thick multilayered and thin layered graphene [ 54 ]. The absorption spectra of MoS 2 /graphene heterostructures prepared in this work have shown comparable absorption bands at 685 and 624 nm identical to those of exfoliated MoS 2 [ 51 , 54 , 55 ]. We observed a blue shift at the 685 and 624 nm for the heterostructure relative to the MoS 2 's absorption bands.…”

“…This generates an electric field at the gold/graphene nanosheets interface and another electric field is produced at the MoS 2 /graphene interface due to the bias. The generation of these electric fields plays a significant role in the separation charge carriers and the subsequent transfer of these carriers to the electrodes, which enhances the photoconductive behavior of MoS 2 /graphene-based photodetectors [ 54 ]. The presence of two electric field generating interfaces in MoS 2 /graphene photodetector is the reason for the higher photocurrent for this device when compared with the MoS 2 -based detector.…”

Edge-Rich 3D Structuring of Metal Chalcogenide/Graphene with Vertical Nanosheets for Efficient Photocatalytic Hydrogen Production

“…The Mo(W)S 2 /3D Gr heterostructure not only showed improved absorbance (Figure S6 improvement in the light absorption properties of the heterostructure with the insertion of the 3D graphene network. 55 Meanwhile, the optical bandgap energies of the samples were 1.82 (MoS 2 ), 1.88 (WS 2 ), 1.83 (MoS 2 /3D Gr), and 1.89 eV (WS 2 /3D Gr), as estimated from the intercept of the linear portion of the plot of (αhν) 2 as a function of energy (hν) (Figure S6(a)). The dynamic behavior of the photo-generated carriers was explored in depth using PL and TRPL analyses.…”

A sulfonated graphene supported nano copper MoS2 network for non-enzymatic simultaneous sensing of dopamine and serotonin

“…The CuNP buds with particle size 410 nm in the TEM imaging (Fig. 4(e)) with a scale bar of 20 nm, 51,52 appear uniformly encapsulated throughout this matrix. SAED patterns appeared indexed to (111), (200), and (220) planes of CuNPs, which are in agreement with the Cu planes obtained from the XRD data (Fig.…”