Surface Passivation of GaN Nanowires for Enhanced Photoelectrochemical Water-Splitting

Handle URI:
http://hdl.handle.net/10754/623915
Title:
Surface Passivation of GaN Nanowires for Enhanced Photoelectrochemical Water-Splitting
Authors:
Varadhan, Purushothaman; Fu, Hui Chun; Priante, Davide ( 0000-0003-4540-2188 ) ; Duran Retamal, Jose Ramon; Zhao, Chao ( 0000-0002-9582-1068 ) ; Ebaid, Mohamed; Ng, Tien Khee ( 0000-0002-1480-6975 ) ; Ajia, Idirs; Mitra, Somak; Roqan, Iman S. ( 0000-0001-7442-4330 ) ; Ooi, Boon S. ( 0000-0001-9606-5578 ) ; He, Jr-Hau ( 0000-0003-1886-9241 )
Abstract:
Hydrogen production via photoelectrochemical water-splitting is a key source of clean and sustainable energy. The use of one-dimensional nanostructures as photoelectrodes is desirable for photoelectrochemical water-splitting applications due to the ultralarge surface areas, lateral carrier extraction schemes, and superior light-harvesting capabilities. However, the unavoidable surface states of nanostructured materials create additional charge carrier trapping centers and energy barriers at the semiconductor-electrolyte interface, which severely reduce the solar-to-hydrogen conversion efficiency. In this work, we address the issue of surface states in GaN nanowire photoelectrodes by employing a simple and low-cost surface treatment method, which utilizes an organic thiol compound (i.e., 1,2-ethanedithiol). The surface-treated photocathode showed an enhanced photocurrent density of −31 mA/cm at −0.2 V versus RHE with an incident photon-to-current conversion efficiency of 18.3%, whereas untreated nanowires yielded only 8.1% efficiency. Furthermore, the surface passivation provides enhanced photoelectrochemical stability as surface-treated nanowires retained ∼80% of their initial photocurrent value and produced 8000 μmol of gas molecules over 55 h at acidic conditions (pH ∼ 0), whereas the untreated nanowires demonstrated only <4 h of photoelectrochemical stability. These findings shed new light on the importance of surface passivation of nanostructured photoelectrodes for photoelectrochemical applications.
KAUST Department:
Electrical Engineering Program; Materials Science and Engineering Program
Citation:
Varadhan P, Fu H-C, Priante D, Retamal JRD, Zhao C, et al. (2017) Surface Passivation of GaN Nanowires for Enhanced Photoelectrochemical Water-Splitting. Nano Letters 17: 1520–1528. Available: http://dx.doi.org/10.1021/acs.nanolett.6b04559.
Publisher:
American Chemical Society (ACS)
Journal:
Nano Letters
Issue Date:
8-Feb-2017
DOI:
10.1021/acs.nanolett.6b04559
Type:
Article
ISSN:
1530-6984; 1530-6992
Sponsors:
KACST-TIC-R2-FP-008 J.H.H. greatly acknowledges the baseline funding from King Abdullah University of Science and Technology (KAUST) and the seed funds from the KAUST Solar Center. B.S.O. and T.K.N. acknowledge the financial support from King Abdulaziz City for Science and Technology (KACST), Grant KACSTTIC R2-FP-008. J.H.H. and V.P. sincerely thank Dr. Ahad Ali Syed and Dr. Xian Bin Wang of the Nanofabrication Core Laboratories, KAUST for their support with atomic layer deposition.
Additional Links:
http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b04559
Appears in Collections:
Articles; Electrical Engineering Program; Materials Science and Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorVaradhan, Purushothamanen
dc.contributor.authorFu, Hui Chunen
dc.contributor.authorPriante, Davideen
dc.contributor.authorDuran Retamal, Jose Ramonen
dc.contributor.authorZhao, Chaoen
dc.contributor.authorEbaid, Mohameden
dc.contributor.authorNg, Tien Kheeen
dc.contributor.authorAjia, Idirsen
dc.contributor.authorMitra, Somaken
dc.contributor.authorRoqan, Iman S.en
dc.contributor.authorOoi, Boon S.en
dc.contributor.authorHe, Jr-Hauen
dc.date.accessioned2017-05-31T11:23:13Z-
dc.date.available2017-05-31T11:23:13Z-
dc.date.issued2017-02-08en
dc.identifier.citationVaradhan P, Fu H-C, Priante D, Retamal JRD, Zhao C, et al. (2017) Surface Passivation of GaN Nanowires for Enhanced Photoelectrochemical Water-Splitting. Nano Letters 17: 1520–1528. Available: http://dx.doi.org/10.1021/acs.nanolett.6b04559.en
dc.identifier.issn1530-6984en
dc.identifier.issn1530-6992en
dc.identifier.doi10.1021/acs.nanolett.6b04559en
dc.identifier.urihttp://hdl.handle.net/10754/623915-
dc.description.abstractHydrogen production via photoelectrochemical water-splitting is a key source of clean and sustainable energy. The use of one-dimensional nanostructures as photoelectrodes is desirable for photoelectrochemical water-splitting applications due to the ultralarge surface areas, lateral carrier extraction schemes, and superior light-harvesting capabilities. However, the unavoidable surface states of nanostructured materials create additional charge carrier trapping centers and energy barriers at the semiconductor-electrolyte interface, which severely reduce the solar-to-hydrogen conversion efficiency. In this work, we address the issue of surface states in GaN nanowire photoelectrodes by employing a simple and low-cost surface treatment method, which utilizes an organic thiol compound (i.e., 1,2-ethanedithiol). The surface-treated photocathode showed an enhanced photocurrent density of −31 mA/cm at −0.2 V versus RHE with an incident photon-to-current conversion efficiency of 18.3%, whereas untreated nanowires yielded only 8.1% efficiency. Furthermore, the surface passivation provides enhanced photoelectrochemical stability as surface-treated nanowires retained ∼80% of their initial photocurrent value and produced 8000 μmol of gas molecules over 55 h at acidic conditions (pH ∼ 0), whereas the untreated nanowires demonstrated only <4 h of photoelectrochemical stability. These findings shed new light on the importance of surface passivation of nanostructured photoelectrodes for photoelectrochemical applications.en
dc.description.sponsorshipKACST-TIC-R2-FP-008 J.H.H. greatly acknowledges the baseline funding from King Abdullah University of Science and Technology (KAUST) and the seed funds from the KAUST Solar Center. B.S.O. and T.K.N. acknowledge the financial support from King Abdulaziz City for Science and Technology (KACST), Grant KACSTTIC R2-FP-008. J.H.H. and V.P. sincerely thank Dr. Ahad Ali Syed and Dr. Xian Bin Wang of the Nanofabrication Core Laboratories, KAUST for their support with atomic layer deposition.en
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttp://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b04559en
dc.subjectIII-Nitridesen
dc.subjectnanowiresen
dc.subjectphotoelectrochemical water-splittingen
dc.subjectsolar fuelen
dc.subjectsurface passivationen
dc.titleSurface Passivation of GaN Nanowires for Enhanced Photoelectrochemical Water-Splittingen
dc.typeArticleen
dc.contributor.departmentElectrical Engineering Programen
dc.contributor.departmentMaterials Science and Engineering Programen
dc.identifier.journalNano Lettersen
kaust.authorVaradhan, Purushothamanen
kaust.authorFu, Hui Chunen
kaust.authorPriante, Davideen
kaust.authorDuran Retamal, Jose Ramonen
kaust.authorZhao, Chaoen
kaust.authorEbaid, Mohameden
kaust.authorNg, Tien Kheeen
kaust.authorAjia, Idirsen
kaust.authorMitra, Somaken
kaust.authorRoqan, Iman S.en
kaust.authorOoi, Boon S.en
kaust.authorHe, Jr-Hauen
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