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

Abstract 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.