Fabrication of a TiO₂/Fe₂O₃ Core/Shell Nanostructure by Pulse Laser Deposition toward Stable and Visible Light Photoelectrochemical Water Splitting

Abstract

Here, we report the fabrication of TiO 2 /Fe 2 O 3 core/shell heterojunction nanorod arrays by a pulsed laser deposition (PLD) process and their further use as photoelectrodes toward high-performance visible light photoelectrochemical (PEC) water splitting. The morphology, phase, and carrier conduction mechanism of plain TiO 2 and TiO 2 /Fe 2 O 3 core/shell nanostructure were systematically investigated. PEC measurements show that the TiO 2 /Fe 2 O 3 core/shell nanostructure enhances photocurrent density by nearly 2 times than the plain ones, increases visible light absorption from 400 to 550 nm, raises the on/off separation rate, and delivers high stability with only a 3% decrease of current density for tests of even more than 14 days. This work provides a method to design an efficient nanostructure by combination of a facile hydrothermal process and high-quality PLD process to fabricate a clean surface and excellent crystallinity for charge separation, transfer, and collection toward enhanced PEC properties.

An ultrathin and compact electron transport layer made from novel water-dispersed Fe3O4 nanoparticles to accomplish UV-stable perovskite solar cells

“…Figure 1d shows the HRTEM of Fe 3 O 4 nanoparticles, from which we can see the high-quality crystalline with 2.52 Å as (311) plane and the surface of nanoparticles is clean which is good for carrier transport. [37,38] Scanning electron microscopy (SEM) was used in here to show the morphology solution. Due to the excellent hydrophilic property of water dispersed nanoparticles, the films can be self-assembled on the ITO surface, and the high-quality iron oxide films can be obtained because of the little change of crystal structure in the annealing process.…”

Recent advances in vacuum- and laser-based fabrication processes for solar water-splitting cells

“…H. Lu et al successfully fabricated TiO 2 /Fe 2 O 3 core–shell heterojunction nanorod arrays using PLD, which was then applied as a photoelectrode in efficient solar water-splitting cells. 87 The study extensively analysed the morphology, phase, and carrier transfer mechanisms of both pristine TiO 2 and TiO 2 /Fe 2 O 3 core–shell nanostructures. PEC measurements indicated that the photocurrent density of the TiO 2 /Fe 2 O 3 core–shell nanostructure nearly doubled compared to that of the pristine TiO 2 structures.…”

CeO2/TiO2 Heterojunction Nanotube Arrays for Highly Efficient Visible-Light Photoelectrochemical Water Splitting

“…Among numerous semiconductor materials, TiO 2 has been widely studied due to its low cost, nontoxicity, good chemical stability, and abundance. , TiO 2 has a suitable band gap to drive the splitting of water into H 2 and O 2 . However, TiO 2 has a wide band gap (∼3.2 eV for anatase) and only responds to UV light, which accounts for 4% of the solar spectrum, severely limiting its practical application. , Furthermore, a short hole diffusion path (less than 10 ns) in TiO 2 inhibits the charge transfer, resulting in a quick recombination rate. , Various strategies, including surface sensitization, , doping, − and constructing heterostructure, − have been explored to improve the PEC performance of TiO 2 by extending the spectral absorption range and promoting the charge separation efficiency. The construction of TiO 2 nanotube (TNT) arrays can vastly enhance the transfer of charge carriers and prolong the recombination time of electron/hole pairs due to their unique tubular structure. ,, However, the PEC performances of TNT arrays should be further improved to achieve high solar-to-H 2 efficiency for commercial applications.…”