Promoting Spatial Charge Transfer of ZrO 2 Nanoparticles: Embedded on Layered MoS 2 /g-C 3 N 4 Nanocomposites for Visible-Light-Induced Photocatalytic Removal of Tetracycline.

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 MoS 2 /g-C 3 N 4 nanocomposite is introduced to zirconium oxide (ZrO 2 ) 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 ZrO 2 @MoS 2 /g-C 3 N 4 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 ZrO 2 NPs. The superior photocatalytic activity of ZrO 2 @MoS 2 /g-C 3 N 4 is due to the dual charge-transfer channel between the MoS 2 /g-C 3 N 4 and ZrO 2 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.