Development and characterization of varying percentages of Ru-doped ZnO (xRu:ZnO; 1% ≤ x ≤ 5%) as a potential material for LPG sensing at room temperature

Five different concentrations of ruthenium were doped in ZnO nanoparticles to synthesize 1%, 2%, 3%, 4% and 5% Ru-doped ZnO utilizing sol-gel technique. Several characterization techniques, viz. X-ray diffraction (XRD), ultraviolet-visible absorption, Fourier transform infrared, elemental dispersive X-ray analysis and scanning electron microscopy (SEM), were utilized for morphological, elemental, structural and optical studies of the synthesized materials. The average crystallite size for each of the materials was calculated with the help of their XRD patterns using Debye-Scherrer formula. These were found to be 14 nm, 17 nm, 19 nm, 22 nm and 24 nm for 1%, 2%, 3%, 4% and 5% Ru-doped ZnO, respectively. By analysing SEM images, the nanosphere and nanoflake types of surface morphologies were observed with varying concentrations of Ru in ZnO nanoparticles. Further, the utility of these materials in LPG sensing was investigated and all the important parameters of LPG sensing, such as response time, recovery time and sensitivity, were determined. The LPG sensing studies suggested that 5% Ru-doped ZnO shows excellent potential in terms of LPG sensing. Its highly porous nature results in greater sensitivity towards LPG along with low response and recovery times and greater stability.