Perovskite LaNiO3/TiO2 step-scheme heterojunction with enhanced photocatalytic activity

LaNiO3/TiO2 step-like composite heterojunction photocatalysts were synthesized via a facial in-situ sol-gel method with different calcination temperatures. The crystal structure and performance of synthetic photocatalyst are characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), UV-vis absorption spectroscopy and X-ray photoelectron spectroscopic spectroscopy (XPS). The results illustrate that binary structure of LaNiO3/TiO2 step-scheme heterojunction can be obtained at a calcination temperature of 700 degrees C, and it extends light-absorption to the visible region. Moreover, the LaNiO3/TiO2 shows superior photocatalytic efficiency with respect to methyl orange (MO) degradation under visible light irradiation for 75 min, the degradation rate in MO solution of 10 mg/L and 20 mg/L are respectively 2 times and 3 times higher than pure LaNiO3. The synthetic photocatalyst also performed effective photocatalytic ability of antibiotic ciprofloxacin under visible light, and the degradation efficiency is higher than pure TiO2 and LaNiO3. Enhancement of organic degradation activity can be attributed to improvement of the electron-hole pairs separation rate caused by the formation of S-scheme heterostructure.