Improvement in ammonia gas sensing properties of Co doped MoO3 thin films prepared by cost effective nebulizer spray pyrolysis method
Amira Ben Gouider Trabelsi, Fatemah H. Alkallas, M. Aslam Manthrammel, Mohd. Shkir, S. AlFaify
Abstract
• Highly sensitive Co doped MoO 3 films were fabricated by nebulizer spray pyrolysis. • XRD study confirm the single phase of MoO 3 films fabrication for Co contents. • The optical studies revealed band gap reduction in Co doped MoO 3 . • 3 % Co:MoO3 film exhibits highest sensitivity (9120 %) with short raise/decay time 54/6s. • It confirms that the 3% Co:MoO3 films will be suitable as ammonia gas sensor. The capacity to detect and monitor NH 3 in the environment in real time has been established using an ammonia (NH 3 ) sensing material consisting of Cobalt (Co) doped Molybdenum trioxide (MoO 3 ) thin films on glass substrates. With Co doping, the XRD peaks of MoO 3 films shifted towards lower angle and increase cell volume in the case of 3% Co doped MoO 3 film compared to other samples, depicts the successful Co doping into the host structure. The chain link particles observed for as-fabricated MoO 3 film increased for Co doped films and obtained maximum particle size for 3% Co doped MoO 3 film. In addition, to test the films elemental and optical properties, energy-dispersive X-ray (EDX) and UV spectroscopy were used to analyze the prepared samples. Simultaneously, we established the gas-sensing characteristics of Co-doped MoO 3 sensors for NH 3 detection at room temperature and attained maximum gas response of 9120 % for 3% Co doped MoO 3 film. The sensor with 3%Co doped MoO 3 sensing film exhibited faster response and recovery times than sensor with undoped MoO 3 film, which is critical for MoO 3 sensor practical applications. Furthermore, the ammonia selectivity of the doped MoO 3 sensors was found to be remarkable.