Fe-doped Ag2S with excellent peroxidase-like activity for colorimetric determination of H2O2

In this work, Fe was doped in the semiconductor Ag2S to form Fe-doped Ag2S nanocomposites (Fe-Ag2S NCs) for enhancing the catalytic performance of pure Ag2S for the first time. According to the investigation of the oxidation reaction of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2, the FeAg2S NCs were proved to possess more excellent catalytic activity compared with that of Ag2S as a peroxidase mimic. Besides, the catalytic mechanism of the Fe-Ag2S was ascribed to the hydroxyl radical (center dot OH) generated from the decomposition of H2O2 in the catalytic oxidation process of TMB. On the basis of the excellent catalytic activity of Fe-Ag2S, a sensitive and efficient colorimetric sensor has been constructed for determining H2O2 and this sensor has a sensitive linear response to H2O2 in the range of 10 -150 mu M with a detection limit of 7.82 mu M. All of the above confirmed that the doping of iron could really improve the catalytic activity of Ag2S. It is believed that Fe-doped Ag2S will open a new way for researchers to optimize the performance of semiconductors. (C) 2019 Elsevier B.V. All rights reserved.