Synergistically enhanced NH3 gas sensing of graphene oxide-decorated Nano-ZnO thin films

This study focuses on enhancing nanostructured ZnO thin films ammonia (NH3) sensing capabilities at room temperature by integrating graphene-oxide (GO) via the drop-casting technique, thereby exploring the possibilities of tailoring NH3 sensing measurements. Structural investigations indicated the hexagonal-wurtzite structure of the sputtered ZnO and GO-decorated thin films. The Raman spectroscopy results validate the electrochemically exfoliated GO, and the X-ray photoelectron spectroscopy characterization revealed the Zn2+ state and oxygen vacancies. The NH3 gas sensing measurements for GO/ZnO revealed a remarkable increase in sensitivity, with a limit of detection (LOD) of 0.1 ppm. This exhibited a response 50 times superior to bare ZnO for 5 ppm of NH3 at room temperature (RT). As a result of decorating GO increased active sites and surface area. This significant enhancement in sensor response underscores the synergistic effect of GO-decoration, and ZnO leading to substantially improved gas-detecting capabilities. The NH3 sensing mechanism of GO/ZnO thin film. [Display omitted] •ZnO thin films were fabricated through DC reactive magnetron sputtering.•Graphene oxide (GO) was prepared via the one-pot synthesis of the electrochemical exfoliation method.•The GO decorated ZnO sensor exhibited an extensive detection range from 0.1 to 100 ppm, enhancing a remarkable limit of detection at 0.1 ppm.•This represents a substantial 50-fold improvement compared to the sensitivity of pristine ZnO.•Response-recovery times of 26 and 86 s were observed towards 0.1 ppm of NH3.