Ruthenium decorated nickel-iron layered double hydroxides (NiFe-LDH) for promoting peroxymonosulfate activation and atrazine degradation

Abstract

With the extensive use of atrazine (ATZ), its potential hazards to ecological environment and human health have raised public concerns. This study reports the effective degradation of ATZ via advanced oxidation processes (AOPs) using peroxymonosulfate (PMS) activated by heterogeneous catalysts of Ru loaded NiFe-LDH blossom nanosheets (Ru/NiFe-LDH). During AOPs, the highly dispersed Ru sites as the main catalytic centers and the NiFe-LDH substrate synergistically stimulated PMS to efficiently produce reactive oxygen species to oxidize ATZ. Under optimal conditions, the degradation activity of ATZ by 5.8Ru/NiFe-LDH/PMS system reached 100% within 90 min. Additionally, it also exhibited good environmental applicability. Besides, electron paramagnetic resonance along with quenching experiments illustrated the production of 1O2, O2• −, •OH, SO4• − and surface-bond radicals during the degradation, where 1O2, •OH and surface-bond radicals were further identified as the dominant oxygen species for the oxidation. The ATZ degradation pathway was determined using the liquid chromatography-mass spectrometry to discern the intermediate products, e.g., dealkylation, alkylic-hydroxylation and dechlororination-hydroxylation processes. This work holds a potential application value for the removal of atrazine and other pollutants.