A self-supporting UiO-66 photocatalyst with Pd nanoparticles for efficient degradation of tetracycline

In situ growth of UiO-66 on zirconium (Zr) substrate was performed to construct a self-supporting photocatalyst through a mild electrochemical method with 1,4-benzenedicarboxylic acid as organic ligand. The as-prepared three-dimensional UiO-66 nanoparticles have abundant pores and corners, providing an ideal interface with large surface area for subsequent decoration of Pd nanoparticles (NPs). The resultant Pd/UiO-66 can efficiently degrade tetracycline (TC) via hydroxyl radical (center dot OH) and superoxide radical (center dot O-2(-)) governing pathway, exhibiting outstanding photocatalytic performance due to fast mass transport endowed by well-dispersed Pd NPs. Under the simulated sunlight irradiation, the electrons of UiO-66 are transferred to Pd NPs, promoting the effective separation of photogenerated electron-hole pairs. Transient fluorescence spectra show that the lifetime of electrons is decreased from 5.08 ns to 3.60 ns with the assistance of Pd NPs, indicating that photogenerated electrons can transfer rapidly. Electrons gathering on the Pd/UiO-66 can react with O-2 to produce center dot O-2(-), and plenty of holes left in UiO-66 host generate center dot OH by oxidizing the adsorbed H2O, producing abundant active species for photocatalytic degradation of tetracycline.

Automated summary

In situ growth of UiO-66 on zirconium substrate with 1,4-benzenedicarboxylic acid as ligand leads to the construction of a self-supporting photocatalyst. The decorated Pd nanoparticles on UiO-66 effectively enhance the photocatalytic performance for tetracycline degradation through efficient electron transfer and rapid generation of reactive species.