TY - JOUR
T1 - Preparation of nanoparticle porous-structured bivo4 photoanodes by a new two-step electrochemical deposition method for water splitting
AU - Ho-Kimura, Socman
AU - Soontornchaiyakul, Wasusate
AU - Yamaguchi, Yuichi
AU - Kudo, Akihiko
N1 - Funding Information:
Acknowledgments: S.H.-K. is grateful to the Science and Technology Development Fund from Macau SAR (FDCT 008/2017/AMJ) and the Multi Year Research Grant from the University of Macau (MYRG2019-00005-IAPME) for funding.
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/1
Y1 - 2021/1
N2 - In the synthesis method of a BiVO4 photoanode via BiOI flakes, a BiOI film is formed by electrochemical deposition in Step 1, and a vanadium (V) source solution is placed by drop-casting on the BiOI film in Step 2. Following this, BiVO4 particles are converted from the BiOI–(V species) precursors by annealing. However, it is challenging to evenly distribute vanadium species among the BiOI flakes. As a result, the conversion reaction to form BiVO4 does not proceed simultaneously and uniformly. To address this limitation, in Step 2, we developed a new electrochemical deposition method that allowed the even distribution of V2O5 among Bi–O–I flakes to enhance the conversion reaction uniformly. Furthermore, when lactic acid was added to the electrodeposition bath solution, BiVO4 crystals with an increased (040) peak intensity of the X-ray diffractometer (XRD) pattern were obtained. The photocurrent of the BiVO4 photoanode was 2.2 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE) under solar simulated light of 100 mW/cm2 illumination. The Faradaic efficiency of oxygen evolution was close to 100%. In addition, overall water splitting was performed using a Ru/SrTiO3:Rh–BiVO4 photocatalyst sheet prepared by the BiVO4 synthesis method. The corresponding hydrogen and oxygen were produced in a 2:1 stoichiometric ratio under visible light irradiation.
AB - In the synthesis method of a BiVO4 photoanode via BiOI flakes, a BiOI film is formed by electrochemical deposition in Step 1, and a vanadium (V) source solution is placed by drop-casting on the BiOI film in Step 2. Following this, BiVO4 particles are converted from the BiOI–(V species) precursors by annealing. However, it is challenging to evenly distribute vanadium species among the BiOI flakes. As a result, the conversion reaction to form BiVO4 does not proceed simultaneously and uniformly. To address this limitation, in Step 2, we developed a new electrochemical deposition method that allowed the even distribution of V2O5 among Bi–O–I flakes to enhance the conversion reaction uniformly. Furthermore, when lactic acid was added to the electrodeposition bath solution, BiVO4 crystals with an increased (040) peak intensity of the X-ray diffractometer (XRD) pattern were obtained. The photocurrent of the BiVO4 photoanode was 2.2 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE) under solar simulated light of 100 mW/cm2 illumination. The Faradaic efficiency of oxygen evolution was close to 100%. In addition, overall water splitting was performed using a Ru/SrTiO3:Rh–BiVO4 photocatalyst sheet prepared by the BiVO4 synthesis method. The corresponding hydrogen and oxygen were produced in a 2:1 stoichiometric ratio under visible light irradiation.
KW - Bismuth vanadate photoanode
KW - Electrochemical deposition
KW - Nanoparticle porous structure
KW - Strontium titanate photocatalyst sheet
KW - Water splitting
UR - http://www.scopus.com/inward/record.url?scp=85100047272&partnerID=8YFLogxK
U2 - 10.3390/catal11010136
DO - 10.3390/catal11010136
M3 - Article
AN - SCOPUS:85100047272
SN - 2073-4344
VL - 11
SP - 1
EP - 21
JO - Catalysts
JF - Catalysts
IS - 1
M1 - 136
ER -