Construction of LaFe1−xMnxO3/attapulgite nanocomposite for photo-SCR of NOx at low temperature

• Attapulgite benefits the gas adsorption and immobilization of nanoparticles.
• Adequate doping of Mn expands the visible absorption range of LaFeO3.
• Coherent LaFe1−xMnxO3/LaMnO3 facilitates the separation of electron-holes.
• Molar fraction of Mn influences the photo-SCR performance at low temperature.

LaFe1−xMnxO3/attapulgite (ATP) nanocomposite was prepared by a sol-gel method. The structures and physicochemical properties were investigated by X-ray diffraction (XRD), Transmission electron microscope (TEM), UV–visible diffused reflectance spectroscopy (UV–vis) and X-ray photoelectron spectroscopy (XPS). LaFe1−xMnxO3/ATP nanocomposite was used as catalyst for photo-assisted selective catalytic reduction (photo-SCR) of NO under visible light irradiation. The impact of the various Mn doping fraction on the NO conversion was investigated. Results indicate that LaFe1−xMnxO3 remains as a perovskite solid solution supported uniformly on the ATP surface when x is less than 0.4. When x is beyond 0.4, LaMnO3 phase co-precipitates with the perovskite LaFe0.6Mn0.4O3 and forms coherent heterojunction of LaMnO3/LaFe0.6Mn0.4O3 on ATP. The photocatalytic deNOx activity of the composite material is the highest when x = 0.6 and the NO conversion reaches as high as 85% even under room temperature.