Z-scheme Ag3PO4/graphdiyne/g-C3N4 composites: Enhanced photocatalytic O-2 generation benefiting from dual roles of graphdiyne

摘要

Ag3PO4 nanoparticles are often considered to be a fascinating and efficient visible photocatalyst because of its high quantum efficiency and excellent activity of O-2 generation from water oxidation. However, the photo-corroded phenomenon and stability during the photocatalytic process reduce the photocatalytic activity. To overcome these disadvantages, strategies of combining Ag3PO4 with two-dimensional materials have been put forward to improve its stability and photocatalytic properties under visible-light irradiation. In this work, a novel Z-scheme Ag3PO4/graphdiyne/g-C3N4 nanocomposite was constructed via a simple electrostatic and pi-pi stacking interaction for the first time. Significantly, such Z-scheme nanostructures show highly oxygen evolution, and 753.1 mu mol g(-1) h(-1) of O-2 was produced with Ag3PO4/graphdiyne/g-C3N4, which was 12.2 times higher than that of Ag3PO4 nanoparticles. Graphdiyne with pi-conjugated structure of sp(-) and sp(2)-hybridized carbon atoms, can not only act as conductive electron mediator bridges to collect photogenerated electrons and boost the O-2 evolution kinetics, but also used as a promising substrate for stabilizing Ag3PO4 in the composite. (c) 2018 Elsevier Ltd. All rights reserved.