Facile Fabrication of ZnO-ZnFe2O4 Hollow Nanostructure by a One-Needle Syringe Electrospinning Method for a High-Selective H2S Gas Sensor

Abstract

Herein, a facile fabrication process of ZnO-ZnFe2O4 hollow nanofibers through one-needle syringe electrospinning and the following calcination process is presented. The various compositions of the ZnO-ZnFe2O4 nanofibers are simply created by controlling the metal precursor ratios of Zn and Fe. Moreover, the different diffusion rates of the metal oxides and metal precursors generate a hollow nanostructure during calcination. The hollow structure of the ZnO-ZnFe2O4 enables an enlarged surface area and increased gas sensing sites. In addition, the interface of ZnO and ZnFe2O4 forms a p-n junction to improve gas response and to lower operation temperature. The optimized ZnO-ZnFe2O4 has shown good H2S gas sensing properties of 84.5 (S = Ra/Rg) at 10 ppm at 250 ∘C with excellent selectivity. This study shows the good potential of p-n junction ZnO-ZnFe2O4 on H2S detection and affords a promising sensor design for a high-performance gas sensor.

Solvothermal Preparation of Oxygen-Vacancy-Rich Nano-ZnO for Electrocatalytic CO2 Reduction in a Flow Cell

“…The surface chemical state of the ZnO catalysts was probed by XPS. As shown in Figure b–d, the satellite peaks appeared at 531.5 and 530.0 eV, indicating the presence of O atoms near the oxygen vacancies and the O bond of Zn–O–Zn, respectively. ,, The oxygen vacancy concentration was quantified by the ratio of the peak areas at 531.5 to 530.0 eV. This corresponds to 0.51, 1.05, and 1.39, for ZnO-W-180, ZnO-EG-150-3, and ZnO-EG-180-3 catalysts, respectively (Figure b–d).…”

“…The crystal structure of the prepared ZnO catalysts was investigated by X-ray diffraction (XRD). As shown in Figure 2a, the ZnO catalysts prepared with different solvents were 28,31,34 The oxygen vacancy concentration was quantified by the ratio of the peak areas at 531.5 to 530.0 eV. This corresponds to 0.51, 1.05, and 1.39, for ZnO-W-180, ZnO-EG-150-3, and ZnO-EG-180-3 catalysts, respectively (Figure 2b−d).…”

Recent advancements in nano sensors for air and water pollution control

“…Zhang et al, 62 are describing a facile fabrication of a flexible gas sensor for rapid detection of hydrogen sulfide (H 2 S) through integrating NO 2 -UiO-66 on electrospun nanofibers membrane (NO 2 -UiO-66 NM). Good H 2 S gas sensing properties has shown a study reported by Park et al, 63 describing the fabrication of ZnO-ZnFe 2 O 4 electro spun hollow nano fibers, enabling enlarged surface area and increasing gas sensing sites. The interface of ZnO and ZnFe 2 O 4 forms a p-n junction for improved sensor response and lowers the operation temperature.…”

Ultraviolet-Induced Gas Sensing Performance of Ag/WO3/rGO Nanocomposites for H2S Gas Sensors

“…Exposure to this gas can cause a multitude of health issues, including but not limited to eye irritation, fatigue, nausea, headache, and pulmonary edema . Even low concentrations of the H 2 S gas can damage the human nervous system and result in loss of consciousness. , The identification of H 2 S as a potential biomarker for asthma and chronic obstructive pulmonary disease highlights the need for the development of affordable and efficient gas sensors capable of detecting low concentrations of this compound. Such sensors are crucial for ensuring both human health and environmental safety.…”