In situ synthesized MoS2/Ag dots/Ag3PO4 Z-scheme photocatalysts with ultrahigh activity for oxygen evolution under visible light irradiation

Abstract MoS 2 /Ag 3 PO 4 heterojunction photocatalysts have attracted great attention in dye degradation and water oxidation, in which Z-scheme plays a critical role in the catalytic performance as a result of energy band structure alignment between MoS 2 and Ag 3 PO 4 . Creating metal sites at composite interfaces as recombination centers of photo-generated electrons from conduction band (CB) of Ag 3 PO 4 and holes from valence band (VB) of MoS 2 is an effective strategy to enhance the charge separation efficiency and photocatalytic performance. Strong coupled MoS 2 /Ag dots/Ag 3 PO 4 ternary heterojunction photocatalysts were fabricated by one-pot precipitation method, in which highly dispersed Ag dots are located at the MoS 2 /Ag 3 PO 4 interfaces and MoS 2 is bonded with PO 4 3- in the form of Mo-O-P. The fabricated MoS 2 /Ag dots/Ag 3 PO 4 photocatalyst presents a 2.8-fold enhancement of photocatalytic activity of water oxidation compared to that of pristine Ag 3 PO 4 , which is achieved for the first time. The great enhancement of photocatalytic performance can be ascribed to the improved Z scheme mechanism with strongly coupled MoS 2 /Ag dots/Ag 3 PO 4 ternary interfaces, in which highly dispersed Ag dots serve as efficient recombination centers resulting in the improved separation of photo-generated holes and electrons of Ag 3 PO 4 as well as photocatalytic activity of oxygen evolution.