2D/2D Wg-C3N4/g-C3N4 composite as “Adsorb and Shuttle” model photocatalyst for pollution mitigation

Abstract

Semiconductor mediated photodegradation of dyes is an important application of heterogeneous photocatalysis. Frequently, transitional metal oxides, sulfides and oxometallate photocatalyst are accentuated in pollutants degradation burdening the cost and secondary pollution of metal leaching. In this work, a metal-free 2D/2D photocatalyst is built by pristine g-C3N4; supported on the acid-treated protonic white g-C3N4 substrate for concurrent high adsorption and excellent visible light absorption as “Adsorb & Shuttle (A&S)” model photocatalyst. Herein, oxidized white g-C3N4 provides excess active sites for binding of dye molecules through adsorption and delivers it to photoactive g-C3N4 sites by surface diffusion, while g-C3N4 degrades the organic pollutants by releasing strong reactive oxidative species (ROS). The formation of face-to-face matching 2D/2D Van der Waal’s (vdW) type homojunction reduced exciton recombination and improved photoactivity. The current A&S strategy may provide new insights into the rational design of g-C3N4 based adsorption induced photocatalysts for effective and rapid decomposition of organic pollutants.