Efficient Removal of Tetracycline from Aqueous Solutions Using Black Flower-Like TiO2@1T/2H-MoS2

Black flower-like 1T/2H mixed-phase molybdenum disulfide (1T/2H-MoS2) nanosheet modified with titanium dioxide (TiO2) was successfully designed and constructed, and effectively improved the efficiency of tetracycline degradation. The properties of the TiO2@1T/2H-MoS2 were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and mass spectrometry (MS). The heterojunction exhibited an excellent degradation effect in ultraviolet mercury lamps. The optimized TiO2@1T/2H-MoS2 had higher degradation efficiency than the bare module, and the degradation efficiency of TiO2@1T/2H-MoS2 was 1.49 times that of 1T/2H-MoS2 and 1.98 times that of TiO2. Quenching experiments show that ·O2− dominates the dark adsorption reaction, and h+ dominates the subsequent photocatalytic reaction. The position of the valence band conduction band of the composites was calculated, and the mechanism of photocatalytic degradation of tetracycline was derived. In addition, the tetracycline intermediate products after 90 min of photocatalysis were determined using liquid chromatography–mass spectrometry (LC-MS), and its degradation path was inferred. TiO2@1T/2H-MoS2 exhibits excellent degradation after reuse, confirming its potential for photocatalytic applications. A semiconductor-coupled photocatalyst for water treatment was designed.