Enhanced photocurrent by MOFs layer on Ti-doped α-Fe_2O_3 for PEC water oxidation

摘要

Low photocurrent density of hematite (alpha-Fe2O3) originating from the inherent defects usually hinders its application in photoelectrochemical (PEC) water oxidation. In this paper, the synergetic effect of increase of oxygen vacancies and in-situ constructing heterojunction by coating MOFs on the alpha-Fe2O3 nanoarrays gives rise to the boosted photo current of alpha-Fe2O3 from 0.25 mA/cm(2) to 2.1 mA/cm(2) at 1.23 V (vs. RHE). The results showed that the appropriate energy band structure engineered by the presence of MOFs layer not only facilitated the PEC water oxidation, but also enhanced the light absorption performance. With inducing oxygen vacancies in further, the intrinsic conductivity of photo anode can be well ameliorated. The value of carrier density is improved one order higher to promote charge transfer between the interfaces and raise the carrier separation efficiency as a result. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.