Enhanced Fenton-like catalytic activity and stability of g-C3N4 nanosheet-wrapped copper phosphide with strong anti-interference ability: Kinetics and mechanistic study

Metal-based Fenton-like catalysts usually activate H2O2 to produce free radicals ((OH)-O-center dot and O-2(center dot)) for the degradation of organic pollutants. However, a catalytic reaction dominated by free radicals is easily interfered with by various inorganic anions and water matrices. Herein, g-C3N4-wrapped copper phosphide (CuxP), as a highly efficient Fenton-like catalyst, was successfully synthesized by a simple low-temperature phosphidation method. The CuxP/g-C3N4 catalyst exhibited excellent catalytic ability for the removal of various organic contaminants over a wide pH range of 3-11. In addition, the catalyst exhibited strong anti-interference ability toward various inorganic anions (Cl-, SO42-, NO3-, F-, H2PO4-, HCO3- and CO32-) and water matrices (lake water, river water, tap water and simulated water matrix). The reasons for this performance were analyzed by verifying the mechanism of the catalytic reaction. Compared to the pure CuxP catalyst, the CuxP/g-C3N4 composite possessed good catalytic stability. The enhanced and deactivated mechanisms of the CuxP/g-C3N4 catalyst were systematically analyzed by a series of characterization techniques. A possible reaction mechanism was also proposed based on the experimental results. This work provides new insights into designing highly efficient metal-based Fenton-like catalysts with strong anti-interference ability to practically treat wastewater. (C) 2021 Elsevier Inc. All rights reserved.