Gamma irradiated Cu-doped TiO₂ nanoparticles for selective ammonia sensing

In this research, the effect of gamma ray doses on volatile organic compound (VOC) sensing properties of Cu doped TiO₂ nanoparticles are studied to further improve the VOC sensing performance. Pure and Cu doped TiO₂ nanoparticles have been prepared by sol-gel technique on Au interdigitated plexiglas substrate and irradiated by gamma-rays with doses varying from 1 to 150 KGy. The irradiation was performed by using ⁶⁰Co as gamma source. The structural, morphology and modifications were analyzed with X-ray diffraction (XRD), scanning electron microscopy (SEM), and Atomic Force Microscopy (AFM) techniques. The sensing performance of these films toward ethanol, methanol, 2-propanol, benzene, toluene, xylene and ammonia vapors has been tested. It was observed that no remarkable sensor response to any vapors except ammonia was observed at room temperature. Changes in sensor’ ammonia sensitivity have been correlated with the gamma radiation dose and Cu doping ratio. Maximum sensing performance was observed with 3% Cu doped TiO₂ exposed to gamma radiation dose of 150 kGy.