Improved visible light photocatalytic activity on Z-scheme g-C3N4 decorated TiO2 nanotube arrays by a simple impregnation method

Abstract Graphitic carbon nitride (g-C3N4) was deposited onto TiO2 nanotube arrays (TNTAs) by a simple impregnation method to afford a Z-scheme g-C3N4/TNTAs photocatalytic system. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectrum, and X-ray photoelectron spectroscopy (XPS). The g-C3N4/TNTAs exhibit improved efficiency for photodegradation of Rh B under visible light irradiation comparing with bare TiO2 nanotube arrays, and CN(10)/TNTAs prepared by 10 times impregnation show the highest activity. The enhanced visible light photocatalytic activity is attributed to the optimized light absorption and effective separation of photogenerated electrons and holes. This article demonstrates a simple way to prepare the Z-scheme heterogeneous photocatalyst with improved performance for potential application in environmental control.