Plug and Play Electrodeposition Cell: A Case Study of Bismuth Ferrite Thin Films for Photoelectrochemical Water Splitting

Abstract

In the present study, we designed and fabricated a cost-effective miniaturized versatile electrochemical deposition cell, which is found to be at par performance as compared with conventional electrodeposition techniques. A case study is being undertaken for the electrodeposition of varied thicknesses of bismuth ferrite (BiFeO3) films on FTO glass substrates. X-ray diffraction (XRD) patterns confirm the structural perovskite phase of BiFeO3 (BFO). UV–visible absorption spectra and Tauc plot of BFO estimate the direct band gap which lies between 1.9 to 2.1 eV. The properties of the bismuth ferrite crystal system such as electronic band structure and density of states (DOS) are investigated theoretically. Photoelectrochemical (PEC) water splitting application is carried out to investigate the best performance of BFO films of varied thicknesses. The best performer (BFO15) working electrode yields a photocurrent density of ∼35 μA cm−2 at 0.2 V vs RHE under visible LED (light intensity of 100 mW cm−2) in neutral 0.5 M Na2SO4 electrolyte. Incident photon to current conversion (IPCE) measurements, electrochemical impedance spectroscopy (EIS), and Mott-Schottky characteristics confirm the best performance of BFO15 photocathode film.