Reduced Graphene Oxide-Ag₃PO₄ Heterostructure: A Direct Z-Scheme Photocatalyst for Augmented Photoreactivity and Stability

A visible light driven, direct Z-scheme reduced graphene oxide-Ag₃PO₄ (RGO-Ag₃PO₄) heterostructure was synthesized by means of a simple one-pot photoreduction route by varying the amount of RGO under visible light illumination. The reduction of graphene oxide (GO) and growth of Ag₃PO₄ took place simultaneously. The effect of the amount of RGO on the textural properties and photocatalytic activity of the heterostructure was investigated under visible light illumination. Furthermore, total organic carbon (TOC) analysis confirmed 97.1 % mineralization of organic dyes over RGO-Ag₃PO₄ in just five minutes under visible-light illumination. The use of different quenchers in the photomineralization suggested the presence of hydroxyl radicals (^.OH), superoxide radicals (^.O₂ ^-), and holes (h⁺), which play a significant role in the mineralization of organic dyes. In addition to that, clean hydrogen fuel generation was also observed with excellent reusability. The 4 RGO-Ag₃PO₄ heterostructure has a high H₂ evolution rate of 3690 μmol h^-1 g^-1, which is 6.15 times higher than that of RGO.