Rational Design of a TpTt/NH 2 ‐MIL‐125(Ti) Dual‐Core Photocatalyst With Structural‐Electronic Synergy for Enhanced Imidacloprid Degradation
Weixia Yang, Shiman Wang, Yusheng Dai, Lu Tian, Yuqing Liu, Haiwei RenABSTRACT
An in situ‐grown TpTt/NH 2 ‐MIL‐125(Ti) covalent organic framework/metal–organic framework (COF/MOF) heterojunction was constructed for visible‐light‐driven degradation of imidacloprid (IMD) coupled with peroxymonosulfate (PMS) activation. The composite combines the visible‐light absorption and π‐conjugated charge‐transport framework of TpTt‐COF with the porous Ti‐containing and amino‐functionalized microenvironment of NH 2 ‐MIL‐125(Ti). X‐ray photoelectron spectroscopy (XPS) and photoelectrochemical analyses indicate interfacial charge redistribution and suppressed charge recombination. The optimized TpTt/NH 2 ‐MIL‐125(Ti)/PMS/Vis system achieved 100% IMD removal within 150 min and retained activity across pH 3–9 and in the presence of common anions. Electron paramagnetic resonance spectroscopy (EPR) spectroscopy and scavenging experiments identified SO 4 • − , •OH, and 1 O 2 as the main reactive species. Liquid chromatography–mass spectrometry (LC‐MS), DFT‐predicted reactive sites, and ECOSAR analysis were integrated to examine the transformation pathway and the predicted ecological toxicity of the products. The distinguishing feature of this study is the integration of an in situ COF/MOF interface, photoassisted PMS activation, and pesticide‐specific transformation and toxicity analysis within one catalyst system.