Low temperature acetylene gas sensor based on Ag nanoparticles-loaded ZnO-reduced graphene oxide hybrid

This paper scrutinizes the fabrication of a chemiresistive type of acetylene (C2H2) gas sensor by synthesizing a silver (Ag)-loaded zinc oxide (ZnO)-reduced graphene oxide (Gr) hybrid via a facile chemical route. The as-synthesized hybrid was characterized in detail in terms of its structural, morphological and compositional properties. The physical properties of the hybrid exhibited a well-structured crystalline nature and mixed phases of Ag, Gr, and ZnO. The morphological characterization revealed that particle like nanostructures of the ZnO and Ag mixer were well distributed and closely affixed onto the surface of thin-layer reduced graphene oxide sheets. At an optimum temperature of 150 degrees C, the 3 wt% Ag-loaded ZnO-Gr hybrid showed preferential detection of acetylene gas with a response value of 21.2 for 100 ppm gas concentrations. The fabricated sensor showed a low detection limit of 1 ppm, fast response and recovery times of 25 s and 80 s, respectively, and good repeatability. Experimental results also showed that the synthesized hybrid had a negligible relative humidity (RH) effect up to 31% RH, and then deteriorated significantly with increasing RH concentrations. After detailed examination, we conclude that an Ag-loaded ZnO-Gr hybrid could be an effective means of fabricating high-performance practical C2H2 sensors. (C) 2014 Elsevier B.V. All rights reserved.