Ex-Situ Formed PANI/WS2 Composite for Improved Selectivity Towards Ammonia Gas

In this study, PANI was synthesized using oxidative polymerization while a colloidal method was followed to synthesize WS2. Subsequently, the two were used to form the PANI/WS
2
composite ex-situ. The synthesized composite was used as a sensor to detect ammonia vapours at room temperature. The composite showed greater response to the ammonia vapours compared to pristine PANI and WS
2
. The improved response is attributed to the heterojunction as the electrons are transferred from p-to n-type material resulting in an increase in resistance and thus an increase in response. The properties of the PANI/WS
2
composite based sensor were evaluated, and the sensor showed good selectivity, sensitivity, stability, and repeatability towards the ammonia vapours at room temperature.