Construction of 3D ternary layered double hydroxides on nickel foam for enhancing dielectric barrier discharge plasma to degrade DUR: Performance, mechanism and energy efficiency

Dielectric barrier discharge plasma (DBDP) has attracted much attention because of its energy saving, high efficiency, and simultaneous production of various active substances. In this work, a three-dimensional (3D) ZnFe-layered double hydroxides (LDH)/nickel foam (NiF) was rationally engineered and synthesized to overcome the problem of active substances insufficient use and clogged pipes in DBDP. With the assistance of ZnFe-LDH/NiF, the removal efficiency of diuron (DUR) increased from 85.98 % to 96.52 %, and the energy efficiency increased from 1074 mg·kWh −1 to 1281 mg·kWh −1 . In various circumstances, the DBDP + ZnFe-LDH/NiF process performed a strong anti-interference ability, high stability, and reusability. The improvement of catalytic degradation ability could be attributed to the combined action of the Fenton-like process and O 3 catalysis, all three elements participating in the electron transfer. With the help of quenching experiments, reactive oxygen species (ROS, including OH, 1 O 2 , and O 2 − ) were identified as the dominant active substance, significantly contributing to DUR elimination. Density functional theory calculation (DFT) and quadrupole-time of flight-liquid chromatography/mass spectrometry (Q-TOF-LC/MS) reached the same conclusion that C N and C−Cl were the main sites attacked by electrophiles and radicals. In summary, the combination of DBDP and ZnFe-LDH/NiF sheds new light on catalyst design and DBDP application.