Sono-precipitation of Ag2CrO4-C composite enhanced by carbon-based materials (AC, GO, CNT and C3N4) and its activity in photocatalytic degradation of acid orange 7 in water

Enhancing the photocatalytic activity of Ag2CrO4 with coupled carbon-based materials like activated carbon, graphene oxide, carbon nanotubes and carbon nitride has been investigated in removal of Acid Orange 7 from wastewater. Sono precipitated Ag2CrO4-C composite based photocatalysts were characterized by XRD, BET, FESEM, STIR and UV-vis DRS and the photocatalytic activity of theses samples was evaluated in terms of degradation amount of acid orange 7 under visible light irradiations. BET analysis showed that with addition of carbon based materials, the specific surface area of the Ag2CrO4-C composite increased. XRD analysis indicated that the crystallinity of Ag2CrO4 peaks decreased after addition of all studied carbon-based materials and C3N4 has lowered the crystallinity of Ag2CrO4 less than others. Higher crystallinity has the positive effect of higher photocatalytic activity because among above mentioned composites, Ag2CrO4-C3N4 photocatalyst exhibited higher photocatalytic activity and stability under visible light irradiations. DRS analysis confirmed good match of electronic structures of Ag2CrO4 and C3N4. On the other hand Ag2CrO4 and C3N4 formed heterojunction which separates photo-generated electron-hole pairs effectively. Also evaluation of photocatalytic reaction in various operating parameters showed Ag2CrO4-C3N4 had the highest photocatalytic activity in neutral pH and 1 g/L of catalyst loading.