Defective UiO-66-NH2 design with enhanced photocatalytic reduction of Cr(vi)

Abstract

In this study, defective UiO-66-NH₂ was synthesized by a simple solvothermal method using benzoic acid and HCl as modulators, in which benzoic acid acts as a defective linker, and HCl serves as a modulator to tailor the amount of defects. The prepared MOF material with structural defects was employed for the photocatalytic reduction of Cr(VI). The results demonstrated that the prepared catalyst exhibited excellent photocatalytic activity in reducing Cr(VI), and its photocatalytic reduction rate was 5.11 times higher than that of defect-free UiO-66-NH₂. The large improvement in the performance is mainly attributed to the resulting defective structure, which promotes the transfer and separation of charge carriers, reduces the recombination rate of charge carriers, enhances the adsorption capacity for Cr(VI), and increases the light absorption and specific surface area. This work provides a facile and effective strategy for the modification of MOFs and a highly efficient catalyst for photocatalytic reduction of Cr(VI).