ZnO-activated SnO2-TiO2 ternary nanocomposite based highly selective formaldehyde sensor at room temperature

Researchers highlight the field of nanosized semiconducting oxide gas sensors because of threats to the atmosphere and health of humans. In this work, Zn-doped SnO2-TiO2 ternary nanocomposites were synthesized via the method of co-precipitation and hydrothermal method. Stannic chloride, titanium isopropoxide and zinc nitrate were used as precursors. Ternary nanocomposites with different composition of ZnO-doped SnO2-TiO2 were obtained and named as STZ1, STZ2 and STZ3. The characterization studies of ternary nanocomposites were determined by X-ray diffractogram, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy and UV-diffused reflectance spectroscopy (UV-DRS) analyses. To construct sensing devices, STZ1, STZ2 and STZ3 were coated on glass substrate as a thick film via doctor blade method. The STZ2 fabricated sensor shows the best selectivity to formaldehyde and attains maximum sensitivity at 100 ppm of gas concentration and at 10 ppm response time and recovery time was 8 s and 9 s, respectively, at room temperature.

Automated summary

Researchers focus on nanosized semiconducting oxide gas sensors due to their potential threats to the atmosphere and human health. In this study, Zn-doped SnO2-TiO2 ternary nanocomposites were synthesized using co-precipitation and hydrothermal methods. Different compositions of ZnO-doped SnO2-TiO2 nanocomposites (STZ1, STZ2, STZ3) were obtained and characterized using X-ray diffractogram, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and UV-diffused reflectance spectroscopy (UV-DRS). Thick films of STZ1, STZ2, and STZ3 were coated onto glass substrates to construct sensing devices. The STZ2 sensor exhibited the best selectivity for formaldehyde, with maximum sensitivity at 100 ppm gas concentration and response and recovery times of 8 s and 9 s, respectively, at room temperature.