Scalable WS2-Graphene Hybrids for Ultralow NO2 Concentration Detection

Identifier:  imarina:9453715

Handle: https://hdl.handle.net/20.500.11797/imarina9453715

Authors:  Malik, SB; Annanouch, FE; Bittencourt, C; Llobet, E

Abstract:
This work presents a facile approach for fabricating hybrid heterostructures of tungsten disulfide (WS2), synthesized via atmospheric pressure chemical vapor deposition (APCVD) and commercial graphene. A simple airbrushing technique, with nitrogen (N-2) as the carrier gas, was employed to fabricate the sensors. The morphological and structural characterizations of the hybrid material revealed a sheet-like synthesis of edge-enriched 2D WS2 decorated with multilayer graphene nanomaterial. The gas-sensing properties of the pristine and hybrid materials were evaluated for nitrogen dioxide (NO2) at various operating temperatures. The hybrid sensor with a WS2 to graphene ratio of 3:1 demonstrated exceptional sensitivity to ultralow NO2 concentrations (10 ppb) at a remarkably low operating temperature of 100 degrees C, outperforming both the graphene and WS2 counterparts. Additionally, the sensor's responses to CO, H-2, C6H6, and NH3 were examined to assess its selectivity. The sensor was tested under different relative humidity conditions (RH at 25 degrees C; 25%, 50%, and 75%). The sensor response nearly doubled at RH = 50%, highlighting its potential for practical applications in selective NO2 detection. The sensor responses eventually reached saturation at 75% RH. In addition, the manuscript provides a detailed discussion of the NO2 gas sensing mechanism.