Elucidation of the optical, electronic, and photoelectrochemical properties of p-type CuFe2O4 photocathodes

Abstract

High-quality thin films of p-type CuFe2O4 photocathode were prepared for the first time on FTO-coated glass substrates by a novel nonaqueous solution using spray pyrolysis method. The films' critical physical and photophysical properties, including morphology, optical properties, carrier transport properties, band position, and photoelectrochemical (PEC) characteristics, were analyzed and estimated. The feasibility of PEC water splitting was systematically evaluated. The prepared reddish-brown CuFe2O4 film exhibits a compact and uniform morphology. Its optical bandgap is approximately 1.42 eV, and it possesses a suitable conduction band position, indicating its capability to facilitate solar-driven water splitting and absorb visible light. Under AM 1.5 simulated solar illumination, the photocurrent density of 12 μA/cm2 was attained in a 1 mol NaOH solution. However, the prepared CuFe2O4 films demonstrate instability under constant light in the electrolyte owing to the copper reduction reaction. These research results offer a fresh insight into the potential application of CuFe2O4 as a photocathode semiconductor in PEC water splitting.