Enhancement of Fe₂TiO₅ Photoanode through Surface Al³⁺ Treatment and FeOOH Modification

Abstract

Fe2TiO5 is recognized as a novel and promising photoanode material for solar water splitting. Here, nanostructured Fe2TiO5 was fabricated on a fluorine-doped tin oxide substrate by an electrospray deposition technique. We utilized surface Al3+ treatment and FeOOH modification to improve performance of the Fe2TiO5 photoanode. After this two-step enhancement, the photocurrent density of the final Fe2TiO5 photoanode is 0.52 mA cm–2 at 1.23 VRHE which is 2.8 times that of the pristine one, and the onset potential is 200 mV lower than before. The enhanced performance can be attributed to a synergetic effect of surface Al3+ treatment and FeOOH modification, since the surface Al3+ treatment accelerates charge transport while the FeOOH layer improves catalytic activity. This strategy of surface modification provides an effective pathway for rational designing of original photoanodes with high practical performance.

Electrochemical Oxidation of Metal–Catechol Complexes as a New Synthesis Route to the High-Quality Ternary Photoelectrodes: A Case Study of Fe2TiO5 Photoanodes

“…First, because Fe 2 O 3 and TiO 2 are both very stable and unreactive binary oxides, the ability to synthesize high-quality Fe 2 TiO 5 using our new method demonstrates the method’s efficacy. Second, as mentioned above, Fe 2 TiO 5 has many advantageous features for use as a photoanode; however, investigations of this compound as a single photoanode have been limited. ,− Therefore, the synthesis of high-quality Fe 2 TiO 5 electrodes also provides us with a great opportunity to systematically examine the photoelectrochemical properties of Fe 2 TiO 5 . Furthermore, we note that although there have been a few theoretical studies on the electronic structure of pristine Fe 2 TiO 5 , − polaron formation and the effect of doping on the charge-transport properties of Fe 2 TiO 5 have not been theoretically investigated.…”

Binary Transition Metal NiFeOx and CoFeOx Cocatalysts Boost the Photodriven Water Oxidation over Fe2TiO5 Nanoparticles

“…This feature can be verified in the diffractograms of the selected NiFeO x /FeTO-S1 and CoFeO x /FeTO-S20 samples (Figure S1), which represent all the other samples prepared in this study, whose patterns are very similar and are not displayed for clarity purposes. [18,20,36,50] As no structural alteration was detected, these patterns point out that the MSD method and the posterior calcination step did not lead to any damage to the original structure and that the pseudobrookite phase of the Fe 2 TiO 5 matrix was maintained.…”

Zn-Doped Fe2TiO5 Pseudobrookite-Based Photoanodes Grown by Aerosol-Assisted Chemical Vapor Deposition

“…Kuang et al . reported an electrospray technique for the preparation of Fe 2 TiO 5 photoanodes and posteriorly modified them by surface state passivation with Al 3+ and by FeOOH decoration, showing both approaches were effective in increasing the resulting photocurrent density values to 0.52 mA cm –2 at +1.23 V RHE . Similarly, Wang et al .…”

“…13 Kuang et al reported an electrospray technique for the preparation of Fe2TiO5 photoanodes and posteriorly modified them by surface state passivation with Al 3+ and by FeOOH decoration, showing both approaches were effective in increasing the resulting photocurrent density values to 0.52 mA cm -2 at +1.23 VRHE. 14 Similarly, Wang et al carried out a F-surface treatment of Fe2TiO5 and increased photocurrent density values due to formation of Ti-F facilitating hole transfer to the electrolyte. 15 The multi-step deposition of thin layers of Fe2TiO5 on top of TiO2 or α-Fe2O3 has also been researched.…”