Photoresponse of GaN:ZnO Electrode on FTO under Visible Light Irradiation

Hashiguchi, Hiroshi; Maeda, Kazuhiko; Abe, Ryu; Ishikawa, Akio; Kubota, Jun; Domen, Kazunari

doi:10.1246/bcsj.82.401

Cited by 50 publications

(74 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…47 ZnO-rich (Ga 1Àx Zn x )(N 1Àx O x ) produced by solution combustion method generated visible driven photocurrent that was 30 times higher than for ZnO. 47 The light source (300 W Xe arc lamp) was passed through a 435 nm long pass lter to isolate the visible-light driven photo-response. 14 The current-voltage curves for lms of bulk (x ¼ 0.40) and nanoscale (x ¼ 0.40, 0.52, and 0.87) (Ga 1Àx Zn x )(N 1Àx O x ) on FTO were measured in aqueous solution with 0.5 M Na 2 SO 4 (Fig.…”

Section: Pec Activity Of Bulk and Nanoscale (Ga 1àx Znmentioning

confidence: 99%

“…14 The current-voltage curves for lms of bulk (x ¼ 0.40) and nanoscale (x ¼ 0.40, 0.52, and 0.87) (Ga 1Àx Zn x )(N 1Àx O x ) on FTO were measured in aqueous solution with 0.5 M Na 2 SO 4 (Fig. 47,49 Nanoscale (Ga 1Àx Zn x )(N 1Àx O x ) showed higher photocurrents by a factor of two and four for x ¼ 0.40 and x ¼ 0.52, respectively. The experiments were carried out at pH 4.5 because the highest photocurrent for the bulk (Ga 1Àx Zn x )(N 1Àx O x ) in PEC oxidation was achieved at this pH.…”

Section: Pec Activity Of Bulk and Nanoscale (Ga 1àx Znmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis and characterization of (Ga_1−xZn_x)(N_1−xO_x) nanocrystals with a wide range of compositions

Lee

Chuang

et al. 2016

J. Mater. Chem. A

View full text Add to dashboard Cite

We describe the synthesis and characterization of wurtzite (Ga 1Àx Zn x )(N 1Àx O x ) nanocrystals with a wide range of compositions and a focus on properties relevant for solar fuel generation. (Ga 1Àx Zn x )(N 1Àx O x ), a solid solution of GaN and ZnO, is an intriguing material because it exhibits composition-dependent visible absorption even though the parent semiconductors absorb in the UV. When functionalized with co-catalysts, (Ga 1Àx Zn x )(N 1Àx O x ) is also capable of water splitting under visible irradiation. Here, we examine the synthesis of (Ga 1Àx Zn x )(N 1Àx O x ) nanocrystals to understand how they form by nitridation of ZnO and ZnGa 2 O 4 nanocrystalline precursors. We find that the ZnO precursor is critical for the formation of crystalline (Ga 1Àx Zn x )(N 1Àx O x ) at 650 C, consistent with a mechanism in which wurtzitenucleates topotactically on wurtzite ZnO at an interface with ZnGa 2 O 4 . Using this information, we expand the range of compositions from previously reported 0.30 # x # 0.87 to include the low-x and high-x ends of the range. The resulting compositions, 0.06 # x # 0.98, constitute the widest range of (Ga 1Àx Zn x )(N 1Àx O x ) compositions obtained by one synthetic method. We then examine how the band gap depends on sample composition and find a minimum of 2.25 eV at x ¼ 0.87, corresponding to a maximum possible solar-to-H 2 power conversion efficiency of 12%. Finally, we examine the photoelectrochemical (PEC) oxidation behavior of thick films of (Ga 1Àx Zn x )(N 1Àx O x ) nanocrystals with x ¼ 0.40, 0.52, and 0.87 under visible illumination. (Ga 1Àx Zn x )(N 1Àx O x ) nanocrystals with x ¼ 0.40 exhibit solar PEC oxidation activity that, while too low for practical applications, is higher than that of bulk (Ga 1Àx Zn x )(N 1Àx O x ) of the same composition. The highest photocurrents are observed at x ¼ 0.52, even though x ¼ 0.87 absorbs more visible light, illustrating that the observed photocurrents are a result of an interplay of multiple parameters which remain to be elucidated. This set of characterizations provides information useful for future studies of composition-dependent PEC properties of nanoscale (Ga 1Àx Zn x )(N 1Àx O x ). † Electronic supplementary information (ESI) available: Fitting of XRD patterns in Fig. 2; TEM images of the samples from Fig. 2; XRD patterns, elemental analysis by ICP-OES, and diffuse reectance spectra of the products from nitridation of the starting mixture with x ¼ 0.78 with varying nitridation time; TEM images of the nitrided products of x ¼ 0.06, 0.24, 0.91, and 0.98; XPS spectra of Zn2p 3/2 , O1s, Ga2p 3/2 , and N1s in samples with several compositions; determination of band gap as a function of composition. See

show abstract

Section: Pec Activity Of Bulk and Nanoscale (Ga 1àx Znmentioning

confidence: 99%

Section: Pec Activity Of Bulk and Nanoscale (Ga 1àx Znmentioning

confidence: 99%

Synthesis and characterization of (Ga_1−xZn_x)(N_1−xO_x) nanocrystals with a wide range of compositions

Lee

Chuang

et al. 2016

J. Mater. Chem. A

View full text Add to dashboard Cite

show abstract

“…The Domen group used the solid reaction method to synthesize a Ga 1-x Zn x N 1-x O x solid solution with a ZnO content of 30% or less and discovered that its band gap decreased as X increased and was 2.5 eV when X = 0.312. Jensen et al .…”

Section: Resultsmentioning

confidence: 99%

“…All the photocurrents of the Ga 1-x Zn x N 1-x O x solid solutions, including the literature data reported thus far, were converted into the value of 1.23 V of an NHE at a pH of 0 and plotted. The photocurrent characteristics of Ga 1-x Zn x N 1-x O x solid solutions have been reported for films formed by the electrophoresis method12 and the doctor blade method16. The photocurrents reported thus far are on the several μA/cm 2 level.…”

Section: Resultsmentioning

confidence: 99%

An artificial photosynthesis anode electrode composed of a nanoparticulate photocatalyst film in a visible light responsive GaN-ZnO solid solution system

Imanaka

Anazawa

MANABE

et al. 2016

Sci Rep

View full text Add to dashboard Cite

The artificial photosynthesis technology known as the Honda-Fujishima effect, which produces oxygen and hydrogen or organic energy from sunlight, water, and carbon dioxide, is an effective energy and environmental technology. The key component for the higher efficiency of this reaction system is the anode electrode, generally composed of a photocatalyst formed on a glass substrate from electrically conductive fluorine-doped tin oxide (FTO). To obtain a highly efficient electrode, a dense film composed of a nanoparticulate visible light responsive photocatalyst that usually has a complicated multi-element composition needs to be deposited and adhered onto the FTO. In this study, we discovered a method for controlling the electronic structure of a film by controlling the aerosol-type nanoparticle deposition (NPD) condition and thereby forming films of materials with a band gap smaller than that of the prepared raw material powder, and we succeeded in extracting a higher current from the anode electrode. As a result, we confirmed that a current approximately 100 times larger than those produced by conventional processes could be obtained using the same material. This effect can be expected not only from the materials discussed (GaN-ZnO) in this paper but also from any photocatalyst, particularly materials of solid solution compositions.

show abstract

“…GaN has a suitable band gap position for water splitting, but it activated only by ultraviolet light irradiation [6][7][8][9][10][11][12][13][14][15]. However the band gap of the solid solutions which was formatted with InN [16][17][18][19] and ZnO [20,21] can be controlled and solar water splitting under visible light irradiation can be achieved. Photoelectrochemical water splitting by using the particulate thin film semiconductor electrode has a strong merit over photocatalytic water splitting with a suspension system because hydrogen and oxygen can be produced separately.…”

Section: Introductionmentioning

confidence: 99%

Photoelectrochemical Properties of GaN Synthesized by the Reaction of Ga with LiNH<sub>2</sub>

Zhang

Kouyama

Miura

et al. 2011

Trans. Mat. Res. Soc. Japan

View full text Add to dashboard Cite

The photoelectrochemical properties of GaN particulate film electrode on Ti substrate were investigated. GaN particulate film electrode was fabricated by means of doctor blade technique. Two kinds of method were used to improve the connection between GaN particles. One is a heat treatment of GaN particulate thin film with LiNH 2 and another one is a heat treatment with TiCl 4 . From the results of the photoelectrochemical properties, GaN electrodes showed n-type semiconducting behavior in 1.0 M HCl electrolyte under UV irradiation. The high photocurrent response was achieved in the electrode with LiNH 2 treatment and TiCl 4 treatment because of its better connection of each GaN particle.

show abstract

Photoresponse of GaN:ZnO Electrode on FTO under Visible Light Irradiation

Cited by 50 publications

References 30 publications

Synthesis and characterization of (Ga_1−xZn_x)(N_1−xO_x) nanocrystals with a wide range of compositions

Synthesis and characterization of (Ga_1−xZn_x)(N_1−xO_x) nanocrystals with a wide range of compositions

An artificial photosynthesis anode electrode composed of a nanoparticulate photocatalyst film in a visible light responsive GaN-ZnO solid solution system

Photoelectrochemical Properties of GaN Synthesized by the Reaction of Ga with LiNH<sub>2</sub>

Contact Info

Product

Resources

About

Photoresponse of GaN:ZnO Electrode on FTO under Visible Light Irradiation

Cited by 50 publications

References 30 publications

Synthesis and characterization of (Ga1−xZnx)(N1−xOx) nanocrystals with a wide range of compositions

Synthesis and characterization of (Ga1−xZnx)(N1−xOx) nanocrystals with a wide range of compositions

An artificial photosynthesis anode electrode composed of a nanoparticulate photocatalyst film in a visible light responsive GaN-ZnO solid solution system

Photoelectrochemical Properties of GaN Synthesized by the Reaction of Ga with LiNH<sub>2</sub>

Contact Info

Product

Resources

About

Synthesis and characterization of (Ga_1−xZn_x)(N_1−xO_x) nanocrystals with a wide range of compositions

Synthesis and characterization of (Ga_1−xZn_x)(N_1−xO_x) nanocrystals with a wide range of compositions