Modification of a thin layer of α-Fe₂O₃ onto a largely voided TiO₂ nanorod array as a photoanode to significantly improve the photoelectrochemical performance toward water oxidation

Abstract

Largely voided TiO2 nanorod array were synthesized and further modified with a thin layer of α-Fe2O3 (Fe2O3@TiO2) by pyrolysis of FeCl3 ethanol solution as a photoanode toward water oxidation, showing significantly improved photoelectrochemical performance over TiO2 nanorod array. Among all Fe2O3 decorated TiO2-based photoanodes, the optimal voided Fe2O3@TiO2 nanorod array photoanode also delivers the largest photocurrent density of 3.39 mA/cm 2 at 1.23 V (vs RHE) and the highest applied bias photon-to-current efficiency (ABPE) (1.153%) under 100 mW/cm 2 UV-vis light illumination. In particular, the ABPE for the as-prepared photoanode is ~3.3 times higher than that of plain TiO2 nanorod array (0.35%), ~11.3 times higher than that of the Fe2O3-modified randomly arranged TiO2 nanorods and ~6.2 times higher than that of the Fe2O3-modified densely arranged TiO2 nanotube array, respectively. The significant enhancement is mainly originated from the large voids in the nanorods array allowing a thin layer of Fe2O3 modification to fully modify the TiO2 nanorods, which improves the absorption of UV light, boosts the charge interface transfer rate, reduces the charge diffusion length and suppresses the charge recombination process. This work demonstrates a feasible route to improve the photoelectrochemical catalytic performance of TiO2 semiconductor toward water splitting.

A Synergistic Effect of Surfactant and ZrO2 Underlayer on Photocurrent Enhancement and Cathodic Shift of Nanoporous Fe2O3 Photoanode

“…S7 ). The similar electron life time values estimated from Bode phase plot are reported for other hematite photoanodes 48 49 . The superior performance from FZC sample originates from the efficient hole transfer to the interface of photoanode-electrolyte junction 50 .…”

Comparison of Different Synthetic Routes of Hybrid Hematite-TiO2 Nanotubes-Based Electrodes

“…Additionally, the satellite at 718.3 eV in all samples indicated the presence of α-Fe2O3 [15,30]. Only in the case of SILAR did a component at smaller energies for the Fe2p 3/2 appear, specifically at around 709.6 eV, which may indicate the formation of FeO using this method [31,32]. Finally, in the Mott-Schottky plot, an E FB of −0.2 V vs. Ag/AgCl indicated a modification of the surface states and, if compared to the previous methods, a more controlled surface composition was observed.…”

Low temperature fabrication of Fe2O3 nanorod film coated with ultra-thin g-C3N4 for a direct z-scheme exerting photocatalytic activities

“…Therefore, these results show that the improvement in several properties, like accelerating electron transfer which can subsequently improve the possibility of photoresponse, can be started through 1D structure. 60,61 Based on these results, the mechanisms of g-C 3 N 4 @Fe 2 O 3 heterostructures are shown in Fig. 10.…”