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

Abstract

A visible light driven, direct Z-scheme reduced graphene oxide-Ag3PO4 (RGO-Ag3 PO4 ) 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.

Highly efficient photocatalytic activity of Ag3PO4/Ag/ZnS(en)0.5 photocatalysts through Z-scheme photocatalytic mechanism

“…As a visible-light responsive semiconductor catalyst with a highly positive valence band, Ag 3 PO 4 has been widely used in solar energy conversion, photocatalysis, and production of photochemical hydrogen from water. [21][22][23] It is also noteworthy that the formation of Ag on silver salts acting as a solid-state electron mediator facilitates charges separation through the Z-scheme system. 24,25 Chen et al 26 prepared a highly efficient Z-scheme Ag 3 PO 4 /AgI photocatalyst, in which Ag nanoparticles act as transmission bridge of the electron-hole pairs.…”

3 D Co3(PO4)2–Reduced Graphene Oxide Flowers for Photocatalytic Water Splitting: A Type II Staggered Heterojunction System

“…In our previous report, [36] for the first time, we introduced the Z-scheme photocatalytic systemi nto the RGO-Ag 3 PO 4 heterostructure. Also, herein, for the first time, we demonstrate the synthesis of au nique 3D flowerlike Co 3 (PO 4 ) 2 structure, which is integratedi nto the RGO sheet through photoreduction from an aqueous solution under visible-light illumination.…”

Repercussion of Solid state vs. Liquid state synthesized p-n heterojunction RGO-copper phosphate on proton reduction potential in water

“…photo energy ( hv ) by extrapolating the tangent lines in Fig. 8e–h 11 , 21 , 22 . Pure RGO also have sufficient absorption in the visible to Uv range as shown in figure.…”

“…Our group has successfully demonstrated the use of RGO as an individual semiconductor photocatalyst and designed in various heterojunction system Ca . Z-scheme, staggered heterojunction system etc, and this heterojunction systems showing great photocatalytic activity too 21 – 23 .…”