Fabrication of NiCoP decorated TiO2/polypyrrole nanocomposites for the effective photocatalytic degradation of tetracycline

Due to the massive discharge of antibiotics in water, it is an urgent matter to remove antibiotics from waste water. The photocatalysts with high stability and activity have attracted extensive attention from researchers. By an in-situ polymerization method, polypyrrole (PPy) was modified on the surface of TiO₂ (named as TiO₂/PPy). By one-step reduction method, NiCoP was grafted on the surface of TiO₂/PPy (named as TiO₂/PPy/NiCoP) to synthesize the photocatalyst of TiO₂/PPy/NiCoP for degradation of tetracycline (TC) antibiotic. The characterization results revealed that NiCoP was deposited on the surface of TiO₂/PPy successfully. The photocatalytic experiment results illustrated that 83.2% of TC could be degraded at natural pH with 20 mg of TiO₂/PPy/NiCoP in 50 mL of TC solution (10 mg/L) under visible light irradiation. The high catalytic activity is attributed to the attachment of NiCoP on the surface of TiO₂/PPy which can enlarge the light response range of TiO₂ effectively. Scavenger studies revealed that the degradation of TC was dominated by ^?O₂^? and h⁺. The photodegradation efficiency of TC with TiO₂/PPy/NiCoP still reached over 74% after 5 consecutive cycles, indicating the potential applications in practical wastewater.