SO2 Gas Detection Using GLAD-Synthesized ZnO Nanowires

Zinc oxide nanowires (ZnO NWs) grown using a simple catalytic-free technique called glancing angle deposition retrofitted to a magnetron sputtering unit have been studied for sulfur dioxide (SO
₂
) gas sensing application. The fabricated sensor showed good response (18.19%) toward SO
₂
at 300 °C under low ppm concentration (3 ppm) level. Temperature-dependent reaction involved between the ionosorbed surface oxygen and the target gas (SO
₂
) on the large surface area of the ZnO NWs might have played a crucial role in enhancing the sensor response. Furthermore, the as-grown sample showed good selectivity toward different interfering gases, such as NO
₂
(2.75%) and CO (1.45%). Also, fast adsorption/desorption kinetics of SO
₂
on the NW surface even at low ppm (3 ppm) concentration was observed resulting in good response (41.82 s) and recovery (84.93 s) process of the sensor.