Improvement in ammonia gas sensing properties of Co doped MoO3 thin films prepared by cost effective nebulizer spray pyrolysis method

Abstract

The capacity to detect and monitor NH3 in the environment in real time has been established using an ammonia (NH3) sensing material consisting of Cobalt (Co) doped Molybdenum trioxide (MoO3) thin films on glass substrates. With Co doping, the XRD peaks of MoO3 films shifted towards lower angle and increase cell volume in the case of 3% Co doped MoO3 film compared to other samples, depicts the successful Co doping into the host structure. The chain link particles observed for as-fabricated MoO3film increased for Co doped films and obtained maximum particle size for 3% Co doped MoO3 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 MoO3 sensors for NH3 detection at room temperature and attained maximum gas response of 9120 % for 3% Co doped MoO3 film. The sensor with 3%Co doped MoO3 sensing film exhibited faster response and recovery times than sensor with undoped MoO3 film, which is critical for MoO3 sensor practical applications. Furthermore, the ammonia selectivity of the doped MoO3 sensors was found to be remarkable.

Keywords

• Cobalt doped MoO3 thin film
• Ammonia gas sensing
• Nebulizer spray method