Active W Sites Promoted by Defect Engineering Enhanced C₂H₆S₃ Sensing Performance of WO₃ Nanosheets

Abstract

Defect engineering has received extensive attention as an effective method to tune the gas sensing properties of semiconductor materials. Here, defective WO 3 (D-WO 3 ) nanosheets were obtained by a simple hydrogenation process with a detection limit as low as 5 ppb for dimethyl trisulfide (DMTS) and a response of 2.3 times that of the initial WO 3 nanosheets to 100 ppb DMTS. Importantly, X-ray photoelectron spectroscopy and Raman spectroscopy confirmed the partial loss of oxygen atoms in D-WO 3 nanosheets, and density functional theory calculations found that the W sites near the oxygen defect showed higher adsorption energy for DMTS and transferred more electrons during the gas interaction, indicating that the active W site caused by oxygen atom loss can effectively enhance the reactivity of twodimensional WO 3 nanosheets. Different from the traditional oxygen defect model, this work reveals the positive effect of active metal sites on gas sensing for the first time, which is expected to provide an effective reference for the sensing application of defect engineering in metal oxides.

Hierarchical Flower-like WO3 Nanospheres Decorated with Bimetallic Au and Pd for Highly Sensitive and Selective Detection of 3-Hydroxy-2-butanone Biomarker

“…This kind of hierarchical nanostructure possesses a large specific surface area, offering plentiful paths for gas diffusion Figure e shows that the lattice fringe spacings of 0.36 and 0.38 nm corresponded to the (200) plane and (002) plane of the monoclinic structure of WO 3 . The bimetallic AuPd nanoparticles are presented in Figure g.…”

“…35 Figure 2e shows that the lattice fringe spacings of 0.36 and 0.38 nm corresponded to the (200) plane and (002) plane of the monoclinic structure of WO 3 . 36 The bimetallic AuPd nanoparticles are presented in Figure 2g. Figure 2h exhibits that the lattice fringe spacings of the AuPd nanoparticles were 0.21 and 0.23 nm assigned to the Au(111) plane and Pd(111) plane, respectively.…”

Single‐Atom Cu Stabilized on Ultrathin WO2.72 Nanowire for Highly Selective and Ultrasensitive ppb‐Level Toluene Detection

“…[25] Combined with electron paramagnetic resonance and UV-visible-near-infrared absorption spectra (Figures S13 and S14, Supporting Information), the introduction of Cu atoms increases the number of oxygen vacancies, i.e., the local atomic structure disorders/defects. [26][27][28] The corresponding Fourier transform infrared spectra results indicate the successful introduction of Cu atoms and the maintenance of WO 2.72 crystal structure (Figure S15, Supporting Information).…”

Application of Polyoxometalates in Chemiresistive Gas Sensors: A Review

“…Among the chemiresistive gas sensors, traditional inorganic semiconductor materials including TiO 2 and SnO 2 and organic semiconductor materials such as polyaniline are the core materials of the sensors. − With the continuous deepening of research, new and developing materials such as 1-D materials (including carbon nanotubes), 2-D materials (including graphene and Mxene), framework materials (including metal–organic frames), and some mesoporous materials have shown good sensing properties in recent years. − It can be seen that the development of new gas-sensitive materials to replace or improve the performance of traditional sensing materials has become one of the research hotspots in the field of chemiresistive gas sensors. However, the performances of traditional inorganic semiconductor gas-sensitive materials are still limited by fast electron–hole recombination.…”