Fabrication of low-temperature acetylene gas sensor based on Ag nanoparticles-loaded hierarchical ZnO nanostructures

Fabrication and evaluation of Ag nanoparticles (NPs)-loaded hierarchical ZnO nanostructure (Ag/ZnO) and their acetylene (C₂H₂) gas sensing properties have been studied. Physical and structural characterisations reveal the formation of high-purity, standard crystalline hierarchical ZnO nanostructures and Ag/ZnO composites. Gas sensing characteristics of the synthesised materials were carried out within the temperature range 25-300°C at different C₂H₂ gas concentrations. At an optimum temperature of 200°C, 5 wt% Ag/ZnO composite showed preferable detection of C₂H₂ with a high sensor response of 92% (1000 ppm), low limit of detection (LOD) of 5 ppm and excellent selectivity towards reducing/oxidising gases. Experimental results demonstrated that addition of appropriate amounts of Ag to ZnO nanostructures enhanced the C₂H₂ sensing performance, which suggests the possibility of fabrication and development of high-performance C₂H₂ sensors.