Plasma-implanted Ti-doped hematite photoanodes with enhanced photoelectrochemical water oxidation performance
Journal
Journal of Alloys and Compounds
Journal Volume
870
Date Issued
2021
Author(s)
Peng, Yong
Ruan, Qingdong
Lam, Chun Ho
Meng, Fanxu
Santoso, Shella Permatasari
Zou, Xingli
Yu, Edward T.
Chu, Paul K.
Hsu, Hsien-Yi
Abstract
Hematite (α-Fe2O3) is recognized as a promising photoelectrode material for photoelectrochemical (PEC) water splitting, as a result of its abundance, non-toxicity, suitable bandgap, and photochemical stability. Nevertheless, the undesirable physical and photophysical behaviors, such as poor conductivity, short diffusion length, and rapid charge-carrier recombination, seriously restrict PEC water splitting efficiency of hematite semiconductors. Herein, we fabricate nanoporous titanium (Ti)-doped α-Fe2O3 thin films by a facile hydrothermal reaction, subsequently utilizing energetic plasma ion implantation with a post-annealing process to significantly enhance the photoelectrochemical water oxidation performance of hematite. On the basis of materials characterization and electrochemical analysis, the optimized Ti-doped Fe2O3, i.e., Ti-4-Fe2O3, exhibits improved photocurrents of 0.55 and 1.07 mA cm−2 at 1.23 and 1.5 V versus RHE respectively under illumination of 100 mW/cm2 with AM 1.5 G spectrum, showing approximately 1.6-fold increases compared to pristine Fe2O3. We attribute this increase to improved charge carrier transport induced by Ti doping that reduces the recombination of light-driven charge carriers. The work utilizing plasma-assisted doping technique provides new insights into the surface engineering of photo-responsive semiconductors for the development of emerging hydrogen technologies. © 2021 Elsevier B.V.
Subjects
Hematite
Photoelectrochemistry
Plasma ion implantation
Surface engineering
SDGs
Type
journal article