Visible-light-induced photodegradation of ofloxacin antibiotic by facile assembled BiFeO3/Bi-modified g-C3N4 heterojunctions

Abstract

The design and assembly of photocatalytic heterojunctions with high visible-light-response have been considered an effective method for successful photocarrier separation, avoiding recombination, and thus boosting the photoactivities of the semiconductors to remove contaminants quickly and efficiently. In this research, we fabricated BiFeO3 (BiFO) nanoparticles and 5 wt% Bi-modified g-C3N4 (BiCN) separately; and then combined them in different percentages (BiFO wt% = 5–40 %) to achieve efficient and novel nanocomposite heterojunctions for visible-light-induced ofloxacin (OFL) degradation and successfully reduced charge recombination. Different description tests (XRD, FESEM, TEM, EDX, DRS, EIS, PL, N2 adsorption-desorption isotherms, and VSM). Unsurprisingly, BiFO/BiCN (20 wt% BiFO) hybrids endorsed superb photocatalytic activity for OFL degradation. Under visible-light irradiation, 20 wt% BiFO/BiCN photocatalyst degraded 95.5 % of OFL in 1.5 h, which compared to bare BiCN and BiFeO3 samples were approximately 3.2- and 4.5-times improvements. This achievement is ascribed to the boosted visible-light harvesting and the great separation of photoinduced e−/h+ pairs as a result of the creation of direct Z-system heterojunction between BiCN and BiFO semiconductors. According to the trapping experiments, •O2−, •OH, and h+ act to different extents as key reactive species in OFL photodegradation. The photocatalytic degradation of 90.7 % was still reached at the end of the fifth photodegradation round (only 5 % reduction), demonstrating the high durability of synthesized BiFO/BCN heterojunction. This work presented significant insights and solutions for photocatalytically degrading antibiotic-contaminated wastewater.