Room temperature benzene gas sensing properties based on Sr-substituted ceria oxide nanopetals.

At room-temperature sensing, the rapid response and recovery time of the sensor (Sr-CeO 2) towards the target gas molecules (25–150 ppm) were similar. This property plays a crucial role in the stability and sensitivity of the sensor under ambient conditions. Furthermore, the sensor surface exhibits this characteristic property over wide range of target gas concentration. The surface-science experiment exhibits the presence of adsorbed oxygen and lattice oxygen, which indicates favorable contribution in sensing mechanism. The attuned morphology of the nanomaterials (nanopetals, small size particles) added advantage to the sensing. The fabricated Sr-substituted sensor demonstrates robust repeatability and high selectivity to benzene. It also illustrates enriched sensor surface for sensing reaction resulting in treble increase of sensitivity as compared to pristine sensor. This sensor outperformed in sensitivity, selectivity and stability measurements, enabling its use for practical applications in industrial and outdoor monitoring. The proposed method of sensor material fabrication is simple and may lead to large scale production of sensors devices. Moreover, the sensor shows ∼96% reproducibility over a long period of time. Optical studies suggest that the bandgap energy of ceria sensor reduces with Sr substitution. Consequently, this enhances the conductivity of the sensor facilitating the response endowment. Under anti-humidity test, the Sr-substituted sensor shows the moderate response to higher humidity and high response to low humidity. Based on overall sensing results, we emphasize that the strontium (Sr) is noble material for room-temperature sensing. • The response and recovery time of the sensor were similar tendency. • Strontium substitution to cerium oxide produces the nanopetals morphology. • Sr-substituted ceria oxide sensor demonstrates good response under low-humidity. [ABSTRACT FROM AUTHOR]