Constructing a novel ternary Fe(III)/graphene/g-C3N4 composite photocatalyst with enhanced visible-light driven photocatalytic activity via interfacial charge transfer effect

Abstract

Interfacial charge transfer effect (IFCT) was introduced into g-C3N4 by grafting Fe(III) species on its surface via a simple impregnation method. It has been shown that the obtained Fe(III)-grafted g-C3N4 photocatalyst exhibited enhanced visible-light absorption, reduced charge recombination and improved photocatalytic activity as compared with those of g-C3N4, due to the interfacial charge transfer between the Fe(III) species and g-C3N4. Furthermore, a novel ternary Fe(III)/graphene/g-C3N4 photocatalyst was successfully constructed by integrating graphene into the binary Fe(III)/g-C3N4 composite as the electron mediator. It has been found that the introduction of graphene made the Fe species show well distribution, smaller size and relatively high content in the ternary photocatalyst as compared with those in the binary one, revealing a synergistic effect between the Fe(III) species and graphene existed in the ternary photocatalyst. Consequently, the photocatalytic activity of the ternary Fe(III)/graphene/g-C3N4 photocatalyst was superior to that of the binary one, originating from its stronger visible-light absorption and more reduced charge combination. The ternary composite that consists of transition metal, graphene and g-C3N4 represents a new kind of high-efficiency visible-light-driven photocatalysts for water disinfection.