Plasmon-Sensitized Graphene/TiO2Inverse Opal Nanostructures with Enhanced Charge Collection Efficiency for Water Splitting.
In this contribution we have developed TiO2inverse opal based photoelectrodes for photoelectrochemical (PEC) water splitting devices, in which Au nanoparticles (NPs) and reduced graphene oxide (rGO) have been strategically incorporated (TiO2@rGO@Au). The periodic hybrid nanostructure showed a photocurrent density of 1.29 mA cm-2at 1.23 V vs RHE, uncovering a 2-fold enhancement compared to a pristine TiO2reference. The Au NPs were confirmed to extensively broaden the absorption spectrum of TiO2into the visible range and to reduce the onset potential of these photoelectrodes. Most importantly, TiO2@rGO@Au hybrid exhibited a 14-fold enhanced PEC efficiency under visible light and a 2.5-fold enrichment in the applied bias photon-to-current efficiency at much lower bias potential compared with pristine TiO2. Incident photon-to-electron conversion efficiency measurements highlighted a synergetic effect between Au plasmon sensitization and rGO-mediated facile charge separation/transportation, which is believed to significantly enhance the PEC activity of these nanostructures under simulated and visible light irradiation. Under the selected operating conditions the incorporation of Au NPs and rGO into TiO2resulted in a remarkable boost in the H2evolution rate (17.8 μmol/cm2) compared to a pristine TiO2photoelectrode reference (7.6 μmol/cm2). In line with these results and by showing excellent stability as a photoelectrode, these materials are herin underlined to be of promising interest in the PEC water splitting reaction.
Department of Chemistry and Nano Science, Division of Molecular and Life Sciences, College of Natural Sciences, Ewha Womans University , 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea.
Ramireddy
http://orcid.org/0000-0002-0370-5490
R
Boppella
Department of Chemistry and Nano Science, Division of Molecular and Life Sciences, College of Natural Sciences, Ewha Womans University , 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea.
Saji Thomas
ST
Kochuveedu
Department of Chemistry and Nano Science, Division of Molecular and Life Sciences, College of Natural Sciences, Ewha Womans University , 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea.
Heejun
H
Kim
Department of Chemical and Biomolecular Engineering, Yonsei University , 50, Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
Myung Jin
MJ
Jeong
Department of Chemistry and Nano Science, Division of Molecular and Life Sciences, College of Natural Sciences, Ewha Womans University , 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea.
Filipe
http://orcid.org/0000-0002-0928-3583
F
Marques Mota
Department of Chemical and Biomolecular Engineering, Yonsei University , 50, Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
Jong Hyeok
http://orcid.org/0000-0002-6629-3147
JH
Park
Department of Chemistry and Nano Science, Division of Molecular and Life Sciences, College of Natural Sciences, Ewha Womans University , 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea.|Division of Chemical Engineering and Materials Science, College of Engineering, Ewha Womans University , 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea.
Dong Ha
http://orcid.org/0000-0003-0444-0479
DH
Kim
TiO2−graphene; inverse opal; photocatalysis; photoelectrochemical water splitting; surface plasmons