Novel isoreticular UiO-66-NH2 frameworks by N-cycloalkyl functionalization of the 2-aminoterephtalate linker with enhanced solar photocatalytic degradation of acetaminophen

Abstract

This work reports for the first time the functionalization of the 2-aminoterephtalate linker of UiO-66-NH2 with cyclopentyl or cyclohexyl rings. The resulting materials displayed reduced bandgaps with enhanced separation of the photogenerated charges due to the inductive electron effect of the cycloalkyl substituent. These functionalized materials displayed higher photocatalytic performance towards the solar abatement of acetaminophen than UiO-66-NH2. The photocatalytic activation mechanism was proposed based on the band alignment and scavenger tests, suggesting the major contribution of holes and superoxide radicals. In particular, UiO-66-NH-C5 exhibited high stability under reaction with low activity loss after reusing. The acetaminophen degradation pathway was also studied indicating that the ACE molecules were coupled to dimers and trimers that were further oxidized. The small bandgap, the band structure, and the photocatalytic performance resulting from the cycloalkyl functionalization of UiO-66-NH2 make it a promising approach to designing novel photocatalysts for solar abatement of emerging contaminants.