Plasmonic gold nanoplates-decorated ZnO branched nanorods@TiO2 nanorods heterostructure photoanode for efficient photoelectrochemical water splitting
Journal
Journal of Photochemistry and Photobiology A: Chemistry
Journal Volume
443
Date Issued
2023-09-01
Author(s)
Chiou, Shang Hau
Ho, Hsin Chia
Liao, Han Ting
Tsao, Chun Wen
Hsu, Yung Jung
Abstract
Transition metal-oxide semiconductors have shown great potential in the renewable energy harvesting and conversion, e.g., photoelectrochemical (PEC) water splitting. However, the existing disadvantages of semiconductors, such as insufficient solar light utilization and fast charge recombination, are urgently needed to be addressed to realize an efficient PEC device. In this work, we synthesized a well-defined ZnO branched nanorods (b-NRs) attached to TiO2 nanorod (NR) arrays on FTO substrate using atomic layer deposition (ALD) and hydrothermal method. Meanwhile, Au triangular nanoplates (TNPs) were also incorporated with ZnO@TiO2 heterostructure by immersing the structure in Au TNPs solution. The ZnO b-NRs@TiO2 NRs and Au TNPs@ZnO b-NRs@TiO2 NRs exhibited the photocurrent densities of 0.490 mA/cm2 and 0.733 mA/cm2 at 1.23 V vs. reversible hydrogen electrode which were 2.8 and 4.2 times of pure TiO2 NR arrays (0.176 mA/cm2), respectively. Incident photon-to-current conversion efficiency measurements showed enhanced photoactivity after Au TNPs decoration. Moreover, the electrochemical impedance spectroscopy and Mott-Schottky analysis provided further evidence that the separation of photogenerated carriers and the transfer kinetics of charge carriers at the semiconductor/electrolyte interface were greatly improved by the ZnO b-NRs modification and Au TNPs decoration. It was concluded that the significantly enhanced PEC water splitting performance was attributed to the synergistic effect of the three-dimensional ZnO@TiO2 composites heterostructure and the localized surface plasmon resonance resulting from Au TNPs. This study reported a facile combination of ALD and hydrothermal method for fabricating ZnO branched heterostructure and decorating Au TNPs to improve the PEC water splitting performance of TiO2.
Subjects
Atomic layer deposition | Au triangular nanoplate | Localized surface plasmon resonance | Photoelectrochemical water splitting | TiO nanorod 2 | ZnO branched heterogeneous nanostructure
SDGs
Type
journal article