Cu Distribution Pattern Controlled Active Species Generation and Sulfamethoxazole Degradation Routes in a Peroxymonosulfate System

Abstract

The distribution pattern of metals as active centers on a substrate influenced persulfate (PS) activation and contaminants degradation. Herein, we applied atomic layer deposition (ALD) to prepare Cu single atom (SA), cluster (C) and film (F) decorated MXene catalysts in a controlled manner. Taking SMX degradation by activated PMS as an example, Cu cluster decorated MXene (C-Cu-MXene) exhibited stronger activity and faster pollutants degradation (k = 0.0485 min-1). 1O2 oxidation and electron transfer played a major role in SA-Cu-MXene and F-Cu-MXene/PMS systems. However, co-existing non-radical and radical (e.g., SO4•-) pathways were presented in C-Cu-MXene/PMS systems. In comparison, SMX degradation routes in C-Cu-MXene/PMS system was found with fewer toxic intermediates. C-Cu-MXene was more prone to adsorb PMS, promoting the cleavage of O-O bond in PMS and generating reactive oxygen species (ROS). Metal sites should be fully utilized to produce specific active species, improving oxidants utilization efficiency.

Keywords: Cu cluster, Distribution pattern, Peroxymonosulfate, Active species, Degradation routes