Fabrication of ZnO Nanoparticles Modified by Uniformly Dispersed Ag Nanoparticles: Enhancement of Gas Sensing Performance

Shuo Wang; Fuchao Jia; Xiaomei Wang; Leqi Hu; Yuping Sun; Guangchao Yin; Tong Zhou; Zhenyu Feng; Parveen Kumar; Bo Liu

doi:10.1021/acsomega.9b04243

Fabrication of ZnO Nanoparticles Modified by Uniformly Dispersed Ag Nanoparticles: Enhancement of Gas Sensing Performance

ACS Omega. 2020 Mar 2;5(10):5209-5218. doi: 10.1021/acsomega.9b04243. eCollection 2020 Mar 17.

Authors

Shuo Wang^{1

2}, Fuchao Jia^{2

3}, Xiaomei Wang², Leqi Hu^{1

2}, Yuping Sun², Guangchao Yin², Tong Zhou², Zhenyu Feng³, Parveen Kumar², Bo Liu²

Affiliations

¹ School of Material Science and Engineering, Shandong University of Technology, Zibo, Shandong 255000, China.
² Laboratory of Functional Molecules and Materials, School of Physics and Optoelectronic Engineering, Shandong University of Technology, Zibo, Shandong 255000, China.
³ Key Laboratory for Colloid and interface Chemistry of Education Ministry, Department of Chemistry, Shandong University, Jinan, Shandong 250100, China.

Abstract

Zinc oxide (ZnO) nanoparticles modified with uniformly dispersed silver (Ag) nanoparticles (Ag-ZnO) were prepared in one step by calcining precursor electrospun nanofibers. The molar ratios of Ag to Zn in the precursor solutions were 0, 1, 3, and 5%. The microstructure of the Ag-ZnO sensor was characterized by scanning electron microscopy and transmission electron microscopy. The existence of metallic Ag was confirmed by X-ray diffraction and X-ray photoelectron spectroscopy, and the gas sensing properties of Ag-ZnO were investigated. The results showed that the ZnO nanoparticles after Ag nanoparticles modification exhibited excellent gas sensing performance to ethanol and hydrogen sulfide (H₂S). The optimal working temperature of the Ag-ZnO sensor significantly decreased for ethanol compared with pure ZnO. The 3% Ag-ZnO sensor exhibited the fastest response to ethanol with the response/recovery times of only 5 and 9 s, respectively. However, all the Ag-ZnO-based gas sensors showed a high response value to H₂S, especially the 3% Ag-ZnO gas sensor exhibited a maximum response value of 298 at 10 ppm H₂S. These results could be attributed to the spillover effect and electron sensitization effect of Ag nanoparticles, which led to more absorbed oxygen species and active sites, and thereby can further enhance the gas sensing performances of ZnO-based gas sensors.