Preparation of Nanoparticle Porous-Structured BiVO4 Photoanodes by a New Two-Step Electrochemical Deposition Method for Water Splitting
Preparation of Nanoparticle Porous-Structured BiVO4 Photoanodes by a New Two-Step Electrochemical Deposition Method for Water Splitting
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DOI：
10.3390/catal11010136
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发表时间：
2021-01-01
期刊：
影响因子：
3.9
通讯作者：
Kudo, Akihiko
中科院分区：
文献类型：
--
作者：
Ho-Kimura, SocMan;Soontornchaiyakul, Wasusate;Kudo, Akihiko
本发明的BiVO 4光阳极的BiOI薄片合成方法，在步骤1中通过电化学沉积形成BiOI膜，在步骤2中通过滴注法将钒（V）源溶液置于BiOI膜上。在此之后，BiVO 4颗粒通过退火从BiOI-（V物种）前体转化。然而，在BiOI薄片中均匀分布钒物质是具有挑战性的。结果，形成BiVO 4的转化反应不会同时且均匀地进行。为了解决这一限制，在步骤2中，我们开发了一种新的电化学沉积方法，该方法允许V2 O 5在Bi-O-I薄片之间均匀分布，以均匀地增强转化反应。此外，当向电沉积浴溶液中添加乳酸时，获得X射线衍射仪（XRD）图案的（040）峰强度增加的BiVO 4晶体。在100 mW/cm（2）光照度的太阳模拟光下，BiVO 4光阳极在1.23 V下相对于可逆氢电极（RHE）的光电流为2.2 mA/cm（2）。法拉第析氧效率接近100%。此外，使用通过BiVO 4合成方法制备的Ru/SrTiO 3：Rh-BiVO 4光催化剂片进行整体水分解。在可见光照射下以2：1的化学计量比产生相应的氢和氧。
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/cm(2) at 1.23 V vs. reversible hydrogen electrode (RHE) under solar simulated light of 100 mW/cm(2) 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.