LAUSR

Abstract An Aminated silver phosphate/graphitic carbon nitride (NH2–Ag3PO4/g-C3N4) nanocomposite with favored band gap energy was produced via facile co-precipitation and thermal pyrolysis processes. The synthesized nanomaterials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS), field scanning electron microscopy (FESEM), transmittance electron microscopy (TEM), and photoluminescence spectroscopy (PL) analyses. The sonophotocatalytic activity of the prepared NH2–Ag3PO4/g-C3N4 in the removal of methylene blue (MB) was investigated. The influence of such effective parameters as NH2–Ag3PO4/g-C3N4 dosage (50–250 mg L−1), the initial MB concentration (3–10 mg L−1), the initial solution pH (4–10), the effect of different salts, and ultrasound power (50–150 W L−1) on the sonophotocatalytic treatment of MB was investigated. The removal efficiency (R%) of 82% was attained at 150 mg L−1 of NH2–Ag3PO4/g-C3N4, 7 mg L−1 of MB, the solution pH of 7, and the power of 150 W L−1 after 100 min ultrasound irradiation. Additionally, the removal efficiency was enhanced by visible light irradiation due to more radical hydroxyls production via the photocatalytic process. However, the results showed that the addition of benzoquinone and EDTA significantly decreased it, confirming that the main active radicals were hole and superoxide. Moreover, the phytotoxicity study via L. minor growth showed an increase in the number of fronds from 70 to 78 in the treated solution. The kinetic of the treatment process was found to follow a second-order rate law.