Photocatalytic degradation is a sustainable technique for reducing the environmental hazards created by the overuse of antibiotics in the food and pharmaceutical industries. Herein, a layer of MoS2/g-C3N4 nanocomposite is introduced to zirconium oxide (ZrO2) nanoparticles to form a “particle-embedded-layered” structure. Thus, a narrow band gap (2.8 eV) starts developing, deliberated as a core photodegradation component. Under optimization, a high photocatalytic activity of 20 mg/L TC at pH 3 with ZrO2@MoS2/g-C3N4 nanocomposite was achieved with 94.8% photocatalytic degradation in 90 min. A photocatalytic degradation rate constant of 0.0230 min–1 is determined, which is 2.3 times greater than the rate constant for bare ZrO2 NPs. The superior photocatalytic activity of ZrO2@MoS2/g-C3N4 is due to the dual charge-transfer channel between the MoS2/g-C3N4 and ZrO2 nanoparticles, which promotes the formation of photogenerated e–/h+ pairs. Charge recombination produces many free electron–hole pairs, which aid photocatalyst reactions by producing superoxide and hydroxyl radicals via electron–hole pair generation. The possible mechanistic routes for TC were investigated in-depth, as pointed out by the liquid chromatography–mass spectrometry (LC–MS) investigation. Overall, this work shows that photocatalysis is a feasible sorbent approach for environmental antibiotic wastewater treatment.

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The efficient use of visible light is necessary to take advantage of photocatalytic processes in both indoor and outdoor circumstances. Precisely manipulating the in situ growth method of heterojunctions is an effective way to promote photogenerated charge separation. Herein, the SrFeO 3 @B-rGO catalyst was prepared by an in situ growth method. At a loading of 10 wt % B-rGO, the nanocomposites revealed an excellent morphology and thermal, optical, electrochemical, and mechanical properties. X-ray diffraction analysis revealed the cubic spinel structure and a space group of Pm ̅ 3m for SrFeO 3 . High-resolution scanning electron microscopy and high-resolution transmission electron microscopy show the core−shell formation between SrFeO 3 and B-rGO. Furthermore, density functional theory of SrFeO 3 was performed to find its band structure and density of states. The SrFeO 3 @B-rGO nanocomposite shows the degradation rate of tetracycline (TC) reaching 92% in 75 min and the highest rate constant of 0.0211 min −1 . To improve the catalytic removal rate of antibiotics, the efficiency of e − and h + separation must be improved, as well as the generation of additional radicals. Radical trapping tests and the electron paramagnetic resonance method indicated that the combination of Fe 2+ and Fe 3+ in SrFeO 3 effectively separated e − and h + while also promoting the development of the superoxide anion ( • O 2 − ) to accelerate TC degradation. The entire TC degradation pathway using high-performance liquid chromatography and its mechanism were discussed. As a whole, this study delineates that photocatalysis is a viable strategy for the treatment of environmental antibiotic wastewater.