Akademik Veri Yönetim Sistemi
CERAMICS INTERNATIONAL, cilt.50, sa.18, ss.32477-32489, 2024 (SCI-Expanded)
Owing to their flexibility and high thermal resistance, para-aramid based KevlarTM TM fabric substrates are an ideal candidate for obtaining flexible gas sensors for new-generation wearable technologies. The morphology of the surface of the substrate where the target gas comes into contact directly affects the important features of the sensor such as detection limit, selectivity, and response. In this context, a feasible technique is introduced to enhance the efficiency of flexible gas sensors utilizing ZnO/KevlarTM, TM, entailing the modification of ZnO morphology. ZnO based gas sensing layers were deposited on KevlarTM TM fabric substrates by a two-stage method. Initially, seed layer was produced on KevlarTM TM fabric using the ultrasonic bath method, with five different seed layer processing times ranging from 1 min to 20 min. In the nucleation, all nanostructured layers were deposited by hydrothermal method with constant parameters and under the same conditions. As the seeding time was increased, nanorods (1D) formed on the surface became flakes (2D), leading to considerable improvement in NH3 gas sensing properties. The sensor with a 5-min seeding time showed a sensitivity of 49 % at an optimal operating temperature of 190 degrees C, while the sensor produced in 20 min showed the best response performance with 169 % at 130 degrees C for 50 ppm NH3 gas. The increase in seeding time not only reduced the operating temperature of the gas sensor through the conversion from 1D nanostructure to 2D, but also significantly increased the sensor response. Under constant hydrothermal conditions and solution concentration, the density per unit area increases. However, after 10 min of seeding, the length of nanorods shortens and turn into a rod-flake hybrid morphology. A superior sensor performance was demonstrated for the samples examined. The obtained results also showed that flexible KevlarTM TM fabric could be a feasible and interesting substrate for nanostructured ZnObased NH3 gas sensors.