Preparation and H2S gas-sensitive properties of hierarchical flower-like Ag/ZnO composites

Abstract

In this research, a hierarchically structured, flower-like ZnO material was successfully synthesized via a solvothermal approach. Subsequently, silver (Ag) nanoparticles were deposited onto the ZnO flowers through ultraviolet light reduction, yielding a highly efficient Ag/ZnO composite material. Notably, the 3 at% Ag/ZnO composite demonstrated a remarkably enhanced response to 100 ppm H₂S at a relatively low operating temperature of 92 °C, reaching 430.0, which is significantly higher than the 157.3 observed for the pristine ZnO material. Furthermore, the detection limit for H₂S was dramatically lowered from 0.05 ppm to a mere 1 ppb. The findings of this research suggest that the incorporation of Ag nanoparticles substantially ameliorates the H₂S sensing capabilities of the pure ZnO material. To delve deeper into the underlying mechanisms, X-ray photoelectron spectroscopy (XPS) was utilized to explore the interaction between the Ag/ZnO sensor and H₂S gas. This analysis provided valuable insights into the reasons behind the observed enhancement in gas sensing performance, shedding light on the synergistic effects of the Ag nanoparticles and the ZnO matrix in the composite material.