Enhanced ^•OH generation and pollutants removal by framework Cu doped LaAlO₃/Al₂O₃

Highly dispersed framework Cu⁺/Cu²⁺ containing LaAlO₃/Al₂O₃ (La-Cu-Al) was synthesized by a solid-liquid mixed sol-gel method. Excessive Al₂O₃ was confirmed to be necessary for the formation of LaAlO₃. The NMR, EXAFS, FTIR and element mapping results revealed that Cu⁺/Cu²⁺ preferred to substitute octahedral Al sites and bonded by Cu-O-Al in the lattice of LaAlO₃. Compared to La₂CuO₄, CuAl₂O₄ and other reported Fenton-like catalysts, La-Cu-Al was more efficient to mineralize refractory pollutants at a wide pH range of 4.0-10.0. More single electrons around Cu center and octahedral Cu⁺ were confirmed to be responsible for the effective reduction of H₂O₂ into powerful ^•OH. Moreover, organic pollutants as electron donors could interact with surface Cu to accelerate Cu²⁺/Cu⁺ cycle and affect O-O bond of H₂O₂ on La-Cu-Al surface, further promoting the reduction of H₂O₂ into ^•OH. These processes resulted in the high H₂O₂ utilization and the highly efficient removal of pollutants on La-Cu-Al.