PANI/CD/SnO₂ Ternary Nanocomposite for Efficient Room-Temperature Ammonia Detection

We report a unique combination of three components in the form of a ternary nanocomposite, PANI/CD/SnO₂, for ammonia gas sensing at room temperature. This nanocomposite was synthesized via in situ chemical oxidative polymerization of aniline, in which other components were incorporated to form binary PANI/CD and ternary PANI/CD/SnO₂ nanocomposites. The fabrication process initially involved optimization of the PANI/CD nanocomposite and then incorporation of an optimized amount of SnO₂ to finally produce the ternary PANI/CD/SnO₂ nanocomposite. The ternary composite demonstrated better sensing properties than those of both PANI/CD (1:0.5) and pristine PANI in terms of sensitivity, selectivity, and response time over a concentration range of 5–100 ppm NH₃. The response of the PANI/CD/SnO₂ nanocomposite was 21.6% towards 100 ppm NH₃, which was higher than that of pure PANI and the PANI/CD nanocomposite. The ternary composite exhibited higher selectivity for ammonia over other gases as compared to PANI and the PANI/CD (1:0.5) nanocomposite. The PANI/CD/SnO₂ composite also achieved a shorter response time (94 s) than pure PANI (162 s) and the PANI/CD (144 s) composite, and it demonstrated a nearly linear variation in response with the analyte concentration. High repeatability and long-term stability further enhanced the possibility of real-world application of the proposed ternary nanocomposite for practical room-temperature ammonia sensing.