Graphene Oxide@3D Hierarchical SnO2 Nanofiber/Nanosheets Nanocomposites for Highly Sensitive and Low-Temperature Formaldehyde Detection

Abstract

In this work, we reported a formaldehyde (HCHO) gas sensor with highly sensitive and selective gas-sensing performance at low operating temperature based on graphene oxide (GO)@SnO 2 nanofiber/nanosheets (NF/NSs) nanocomposites. Hierarchical SnO 2 NF/NSs coated with GO nanosheets showed enhanced sensing performance for HCHO gas, especially at low operating temperature. A series of characterization methods, including X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) were used to characterize their microstructures, morphologies, compositions, surface areas and so on. The sensing performance of GO@SnO 2 NF/NSs nanocomposites was optimized by adjusting the loading amount of GO ranging from 0.25% to 1.25%. The results showed the optimum loading amount of 1% GO in GO@SnO 2 NF/NSs nanocomposites not only exhibited the highest sensitivity value (R a /R g = 280 to 100 ppm HCHO gas) but also lowered the optimum operation temperature from 120 • C to 60 • C. The response value was about 4.5 times higher than that of pure hierarchical SnO 2 NF/NSs (R a /R g = 64 to 100 ppm). GO@SnO 2 NF/NSs nanocomposites showed lower detection limit down to 0.25 ppm HCHO and excellent selectivity against interfering gases (ethanol (C 2 H 5 OH), acetone (CH 3 COCH 3 ), methanol (CH 3 OH), ammonia (NH 3 ), methylbenzene (C 7 H 8 ), benzene (C 6 H 6 ) and water (H 2 O)). The enhanced sensing performance for HCHO was mainly ascribed to the high specific surface area, suitable electron transfer channels and the synergistic effect of the SnO 2 NF/NSs and GO nanosheets network.Molecules 2020, 25, 35 2 of 15 sensitivity, poor selectivity and/or relatively high optimum operation temperature. Hence, designing and developing gas sensors with high sensibility, excellent selectivity and lower optimum operation temperature is urgent and important.Graphene is a typical two-dimensional (2D) sheet of sp 2 bonded carbon with excellent electronic applications. Due to its unique physical and chemical properties, many efforts have been carried out on the application of graphene as sensing elements [12]. These advantages, including its high conductivity, large surface area and low electrical noise, make it a promising platform for preparing new sensors [13][14][15]. In order to prepare a new gas sensor with high sensing performance, low operation temperature and excellent selectivity, the combination of graphene and metal oxide semiconductors is a new strategy to enhance sensing performance compared to pure sensing materials [16]. Gaikwad et al. have reported a NH 3 gas sensor based on Polyaniline/Graphene Oxide (PANI/GO) by nanoemulsion method [17]. Sun et al. have synthesized rGO/ZnSnO 3 composites as a sensing material for detecting HCHO gas by a facile solution-based self-assembly synthesis method [18]. Rong et al. have prepared microstructures of SnO 2 @rGO nanocomposites for HCHO detection by facile thermal treatment ...

High-Performance Cataluminescence Sensor Based on Nanosized V2O5 for 2-Butanone Detection

“…Volatile organic compounds (VOCs) in residential buildings and in the workplace pose serious threats to public health [ 1 , 2 , 3 ]. As a typical colorless VOC, 2-butanone is produced industrially on a large scale, is widely used as a common solvent, denaturing agent and cleaning agent.…”

Breakthroughs in the Design of Novel Carbon-Based Metal Oxides Nanocomposites for VOCs Gas Sensing

“…In addition, Wan et al [ 78 ] reported a formaldehyde gas sensor with highly sensitive and selective gas sensing performances at low temperatures based on graphene oxide (GO)@SnO 2 nanofiber/nanosheets (NF/NSs) synthesized by electrospinning technique followed by a hydrothermal step ( Figure 5 l). Figure 5 m shows the XRD patterns of pristine SnO 2 NF/NSs, GO@SnO 2 NF/NSs nanocomposites and GO.…”

“…Elsevier, 2019. ( l ) Sketch of the preparation process of GO@SnO 2 nanofiber (NF)/nanosheets (NSs) [ 78 ]. ( m ) XRD patterns of GO, SnO 2 NF/NSs and GO@SnO 2 NF/NSs nanocomposites with different GO concentrations [ 78 ].…”

“…( l ) Sketch of the preparation process of GO@SnO 2 nanofiber (NF)/nanosheets (NSs) [ 78 ]. ( m ) XRD patterns of GO, SnO 2 NF/NSs and GO@SnO 2 NF/NSs nanocomposites with different GO concentrations [ 78 ]. ( n ) Sensing responses toward 100 ppm of formaldehyde at different operating temperatures [ 78 ].…”

“…( m ) XRD patterns of GO, SnO 2 NF/NSs and GO@SnO 2 NF/NSs nanocomposites with different GO concentrations [ 78 ]. ( n ) Sensing responses toward 100 ppm of formaldehyde at different operating temperatures [ 78 ]. ( o ) Response of the gas sensors to different test gases at their respective optimal temperature [ 78 ].…”