Preparation of TiO/Fe-MOF n‒n heterojunction photocatalysts for visible-light degradation of tetracycline hydrochloride.

Visible-light-assisted photocatalysis has been recognized as an effective solution to the degradation of various pollutants including antibiotics, pesticides, herbicides, microplastics, and organic dyes. Herein, an n-n heterojunction TiO/Fe-MOF photocatalyst is reported, designed via solvothermal synthesis route. TiO/Fe-MOF photocatalyst was characterized by XPS, BET, EIS, EDS, DRS, PL, FTIR, XRD, TEM, SEM and HRTEM techniques. Inspired by XRD, FTIR, XPS, EDS, TEM, SEM, and HRTEM analyses, the successful synthesis of n-n heterojunction TiO/Fe-MOF photocatalysts was proved. The migration efficiency of the light-induced electron-hole pairs was confirmed by the PL and EIS tests. TiO/Fe-MOF exhibited a significant performance for tetracycline hydrochloride (TC) removal under visible light irradiation. TC removal efficiency for TiO/Fe-MOF (15%) nanocomposite reached 97% within 240 min, ca. 11 times higher than pure TiO. The photocatalytic enhancement of TiO/Fe-MOF could be attributed to the broadening the light response range, forming an n-n junction between Fe-MOF and TiO components, suppressing charge recombination. Based on recycling experiments, TiO/Fe-MOF had a good potential to be used in consecutive TC degradation tests.