Ghazal Salehi - Department of Chemistry, Faculty of Science, Tarbiat Modares University, Tehran, Iran
Ali Reza Mahjoub, - Department of Chemistry, Faculty of Science, Tarbiat Modares University, Tehran, Iran
Reza Abazari - Department of Chemistry, Faculty of Science, Tarbiat Modares University, Tehran, Iran

Through a green protocol, Ni-Al layered double hydroxides (Ni-Al LDHs) with molar ratio of 1:1, 2:1, and 3:1 were prepared in ultrasonic bath at a low temperature using hexamethylenetetramine as template. Effects of the initial reagent concentration, ultrasound illumination power, and reaction time on the shape and size of the nanostructured Ni-Al LDHs were investigated. Under ultrasonic irradiation, the synthesized nanostructures were combined with graphitic carbon nitride (g-C3N4) as a new nanocomposite for photocatalytic degradation of Rhodamine B (RhB) dye as a pollutant model. Field emission scanning electron microscopy (FE-SEM), powder XRD, transmission electron microscopy (TEM) and FT-IR spectroscopy were employed to characterize the Graphitic carbon nitride@nickel-aluminium layered double hydroxide nanocomposites (g-C3N4@Ni-Al-LDH nanocomposites). g-C3N4@Ni-Al-LDH nanocomposites demonstrated a more advanced photocatalytic behavior under visible light, which can be explained by the increased specific surficial area and decreased rate of the electron-hole recombination. The optimal percentage of weight for g-C3N4 was 40%. Our synthesized g-C3N4/Ni-Al LDH seem to be highly promising for future applications in different commercial fields and industries. Moreover, they are applicable for photodegradation of other organic pollutants