Strontium ferrite oxide (Sr<inf>3</inf>Fe<inf>2</inf>O<inf>7</inf>) decorated TiO<inf>2</inf> photoanode improves the photo-absorption and photoelectrochemical cell efficiency

Abstract

In this study, a coating of strontium ferrite oxide (SFO), Sr3Fe2O7, on TiO2 demonstrated an enhancement in photoelectrochemical cell (PEC) performance. Pure TiO2 and SFO decorated TiO2 (SFO/TiO2) were synthesized using the hydrothermal method. The concentration of SFO precursor in this study varied between 0.5, 1.0, and 1.5 mmol. Most of the optimized SFO concentration showed the better Applied Bias Photon-to-current Efficiency than the pure TiO2. The structure, chemistry, and surface morphology of TiO2 and SFO/TiO2 materials were investigated using several techniques, including X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The UV–visible spectra revealed that SFO was able to reduce the energy band gap of pristine TiO2 from 3.09 to 2.55 eV. The photoluminescence spectroscopy displayed that almost SFO/TiO2 materials exhibited the lower recombination time than the pristine TiO2. Moreover, 1.0 mmol of SFO/TiO2 exhibited the highest photocurrent density, at approximately 12.5 μA/cm2, which was 12 times greater than pure TiO2. The Mott-Schottky analysis revealed the energy band edge of SFO and the TiO2 was well alignment. Therefore, SFO plays a crucial role in improving the photo-absorption efficiency of PEC cell. The enhanced PEC performance was achievable due to the materials’ tailored light response.