Fine Tuning of Ag3PO4/g-C3N4 Hybrid Nanostructure Catalyst for Natural Sunlight-Assisted Cationic Dye Neutralization

Photocatalysis is a promising route for the environmentally friendly destruction of organic pollutants and recycling the polluted water in industrial contexts for future environmental challenges. In this novel research work, the coupling of definite proportions of silver phosphate and g-C3N4 is carried out sonochemically for engineering S-scheme Ag3PO4/g-C3N4 heterojunctions. With the data obtained from a N2-adsorption–desorption isotherm, a diffuse reflectance spectrum, X-ray diffraction, a high-resolution transmission electron microscope and zeta potential measurement, as-synthesized nanocomposites are fully characterized and defined. Successful coupling of Ag3PO4/g-C3N4 heterojunctions was verified given the existence of diffraction peaks of g-C3N4 and Ag3PO4; the shift in the peak position of the DRS spectrum of g-C3N4 from 440 to 463 nm; and the decrease of 68% in the photoluminescence emission peak. The crystalline size of the nanocomposite decreased from 76 to 25 nm, which was ascribed to coupling of Ag3PO4 on g-C3N4 under sonochemical conditions. The as-synthesized nanocomposites exhibited different trends in the destruction of rhodamine B dye. The experimental results indicated that the sample containing 15 weight % of Ag3PO4 degraded 89% of the RhB dye. Precise analysis of reactive radicals species experiments indicated that superoxide radicals and positive roles directed the charge transportation between g-C3N4 and Ag3PO4 semiconductors toward the S-scheme mechanism that produces charge radicals of auspicious redox efficiency.