“…Various devices have been utilized for CO detection, including surface acoustic waves, 3 optical gas sensors, 4 electrochemical gas sensors, 5 and metal oxide gas sensors. 6 Among these, metal oxide semiconductor (MOS) sensors have gained widespread use for gas sensing due to their high sensitivity, excellent stability, and ease of fabrication. 7 In recent years, extensive research on MOS sensor materials has examined n-type semiconductors like ZnO, 8 SnO 2 , 9,10 In 2 O 3, 11 and WO 3 , 12 alongside p-type semiconductors including NiO, 13 CuO, 14 and Co 3 O 4 .…”