posted on 2022-11-14, 05:29authored byQian Xu, Bingzhi Qian, Yu Zhang, Hui Li, Yang Wu
Searching earth-abundant materials for photocatalytic
fuel cells
(PFCs) remains an important goal for energy conversion and storage,
and the construction of semiconductor composite materials is an effective
method to improve the photochemical properties of photoelectrodes
in PFCs. Herein, a simple hydrothermal method is used to load an Fe2O3 layer on a BiVO4 film for use in
the photoanode of a PFC, and the electrochemical results show that
the short-circuit current density (Jsc) and the open-circuit voltage (Voc)
of the PFC reach 3.05 mA/cm2 and 0.84 V under simulated
solar irradiation, respectively. Furthermore, a detailed analysis
of the density of states, charge density difference, and work functions
of the Fe2O3/BiVO4 heterojunction
is discussed by the density functional theory (DFT) method, showing
the proper band alignment and the existence of a built-in electric
field at the interface with the direction from BiVO4 to
Fe2O3, which greatly improves the performance
of the PFC. This research provides a clear mechanism for the Fe2O3/BiVO4 heterojunction in the PFC system.