2D/0D SnSe2/TiO2 nanocomposites for trace NO2 detection under H2S interference at room temperature

Complex gas environments and the demand for room temperature detection will provide challenges for chemo-resistive-type gas sensors in a variety of applications. In this work, 2D/0D SnSe2/TiO2 composite is used as a sensing material, displaying good sensitivity and specificity to ppb-level NO2 at ambient temperature (25 °C). The response value and time of the SnSe2/TiO2 sensor are 207 % and 139s when exposed to 100 ppb NO2, as opposed to 62 % and 183s for the pristine SnSe2 sensor. The composite sensor also offers great long-term stability for NO2 and good gas selectivity. Notably, the SnSe2/TiO2 sensor's mixed gases (NO2+H2S) measurement is done to examine its NO2 detection capacity in the presence of interfering gas. The constructed composite sensor can accurately detect NO2 even if the concentration of the reductive interfering H2S is 66.7 times higher than that of the oxidative target NO2. The effective usage of SnSe2 modified by TiO2 for low-concentration, room-temperature NO2 detection in a complex gas environment is shown by the composite sensor's pleasing gas detection results.