Effect of Oxygen Functional Groups in Reduced Graphene Oxide-Coated Silk Electronic Textiles for Enhancement of NO₂ Gas-Sensing Performance

Abstract

An electronic textile-based NO 2 gas sensor was fabricated using commercial silk and graphene oxide (GO). It showed a fast response time and excellent sensing performance, which was simply accomplished by modifying the heat-treatment process. The heat treatment was conducted at 400 °C and different heating rates of 1, 3, and 5 °C/min. Compared with our previous research, the response time significantly decreased, from 32.5 to 3.26 min, and we found that the highest response was obtained with the sensor treated at a heating rate of 1 °C/min. To find the reason for this enhanced sensing performance, the morphology, structure, and chemical composition of the reduced GO (rGO) were investigated, depending on the thermal treatment process, using scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. We also measured the temperature-dependent resistance of rGO, which was well described by the fluctuation-induced tunneling (FIT) model. These results revealed that the rGO thermally treated with 1 °C/ min of heating rate had the largest amount of oxygen groups. This means that the oxygen functional groups play an important role in NO 2 gas-sensing performance.

Flexible Sensory Systems: Structural Approaches

“…The various advantages of these fabrics have been applied to industry [ 260 , 290 , 291 ] and energy harvesting [ 292 , 293 , 294 , 295 ], and, in particular, have led to the development of smart textiles for healthcare monitoring [ 256 , 296 , 297 , 298 ].…”

Intrinsically Breathable and Flexible NO2 Gas Sensors Produced by Laser Direct Writing of Self-Assembled Block Copolymers

“…As the F127/resol mass ratio increases from 1:2 to 3:2, the response in the absolute value increases from −2.3 to −5.1‰, which is likely attributed to the increased defects and adsorption sites as evidenced by the increased I D /I G ratio (Figure S9). 46,47 The larger pore size in LIG prepared by the higher F127/resol mass ratio may also expedite the adsorption rate of NO 2 molecules during the same exposure time for a larger gas response. The decoration of the Ag NPs, as confirmed by the binding energies of Ag 3d 5/2 (368.3 eV) and Ag 3d 3/2 (374.3 eV) in the XPS analysis 48 (Figure S10), on the porous LIG further enhances the sensor response by an The enhancement is likely attributed to the higher specific surface area and increased active sensing sites in the Ag/LIG composites.…”

Graphene oxide fiber microelectrodes with controlled sheet alignment for sensitive neurotransmitter detection

“…31,32 The D′ (∼1635 cm −1 ) band is attributed to the disorder-induced phonon mode due to crystal defects. 33 The D″ band (∼1550 cm −1 ) remains a topic of controversy, however, recent research indicates a significant correlation between the band and the oxygen content. 34 Based on this understanding, peak fitting was employed, incorporating all four bands as depicted in Fig.…”