Construction of p-n type heterojunction for effective photo-generated electron separation and visible light hydrogen evolution

With the development of research on the photocatalytic water splitting and hydrogen (H-2) precipitation, cobalt ferrite and molybdate have begun to appear as catalysts for the study of photocatalytic hydrogen precipitation. In this paper, the p-n heterojunction CoFe2O4/NiMoO4 (CFO/NMO) is prepared by hydrothermal method. The constructed p-n type (type II) heterojunction CFO/NMO has the highest hydrogen evolution (Eosin Y as a sensitizer), which is 7.39 times and 1.95 times that of elemental CFO and NMO, respectively. After the CFO and NMO form a heterojunction, a built-in electric field is formed inside to effectively separate the photogenerated carriers. At the same time, the dense interface of the heterojunction also promotes the transfer of photogenerated carriers and promotes the reduction of H+ protons on this catalyst surface. In short, this work provides more possibilities for the field of photocatalytic hydrogen evolution from molybdate and cobalt ferrite compounds. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.