UV-light-activated H2S gas sensing by a TiO2 nanoparticulate thin film at room temperature

A UV-light-activated TiO₂ thin film gas sensor composed of nanoparticles is reported for H₂S detection at room temperature. TiO₂ nanoparticulate thin films were fabricated by bar coating of a mixture of TiO₂ powder and acetic acid. The morphology and structural properties of the films were examined by scanning electron microscopy, X-ray diffraction, photoluminescence spectroscopy, and absorption spectroscopy. The nil response to H₂S was significantly enhanced by UV light irradiation in the response levels and response/recovery kinetics. The effect of the sensor conductance and light intensity towards sensor optimization was discussed. The sensor exhibited high gas selectivity, repeatability, and linearity for practical applications of the sensor, but the interference of humidity on the sensing process needs to be solved. The results exhibited a simple way to detect parts per million concentrations of H₂S at room temperature.