“…In general, they are employed as adsorbents for the removal of several types of pollutants (dyes [ 43 , 44 ], metals [ 45 , 46 ]) or as photosensitizers [ 47 , 48 , 49 , 50 ]. Among COPs, polyaniline (PANI) occupies a special place for its unique characteristics and, therefore, it can be considered a valid candidate to be used in the fields, where its interesting redox properties related to the presence of imino-quinoid/amino-benzenoid groups can make the difference [ 42 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 ]. So far, concerning NOx, COPs have been largely studied to fabricate gas sensors [ 59 , 60 , 61 ].…”