Defective UiO-66-NH2 modified TCPP enhanced the photocatalytic reduction of Cr(VI)

In this investigation, UiO-66-NH2 was effectively synthesized through a solvothermal approach, utilizing benzoic acid and hydrochloric acid (HCl) as modulating agents. This synthesis process intentionally introduced defects mediated by benzoic acid, and the degree of these defects was precisely adjusted by the concentration of HCl. Subsequently, the material underwent a covalent modification process through an amidation reaction, resulting in the attachment of tetrakis (4-carboxyphenyl) porphyrin (TCPP). The results demonstrated a significant improvement in the photocatalytic reduction of Cr(VI), showcasing a 125 % elevation in reduction efficiency as compared to the unmodified UiO-66-NH2 material serving as the baseline. The performance enhancement is due to the synergistic effect of the defect structure and TCPP modification, which enhances the light absorption, promotes charge transfer and separation, reduces the recombination rate, and improves the adsorption capacity and light absorption efficiency of Cr(VI). This research introduces an innovative approach and a highly effective catalyst, offering a novel solution for modifying metal-organic frameworks (MOFs) and enhancing their photocatalytic performance in the reduction of Cr(VI). © 2024 Elsevier Ltd