Thin layers of BiVO₄/V₂O₅ were prepared on FTO substrates using pulsed laser deposition technique. The method of cobalt hexacyanocobaltate (Cohcc) synthesis on the BiVO₄/V₂O₅ photoanodes consists of cobalt deposition followed by electrochemical oxidation of metallic Co in K₃[Co(CN)₆] aqueous electrolyte. The modified electrodes were tested as photoanodes for water oxidation under simulated sunlight irradiation. Deposited films were characterized using UV-Vis spectroscopy, Raman spectroscopy, and scanning electron microscopy. Since the V₂O₅ is characterized by a narrower energy bandgap than BiVO₄, the presence of V₂O₅ shifts absorption edge (ΔE = ~0.25 eV) of modified films towards lower energies enabling the conversion of a wider range of solar radiation. The formation of heterojunction increases photocurrent of water oxidation measured at 1.2 V vs Ag/AgCl (3 M KCl) to over 1 mA cm^-2, while bare BiVO₄ and V₂O₅ exhibit 0.37 and 0.08 mA cm^-2, respectively. On the other hand, the modification of obtained layers with Cohcc shifts onset potential of photocurrent generation into a cathodic direction. As a result, the photocurrent enhancement at a wide range of applied potential was achieved.

Graphical Abstract

使用脉冲激光沉积技术在FTO基板上制备BiVO ₄ / V ₂ O ₅薄层。在BiVO ₄ / V ₂ O ₅光电阳极上合成六氰基钴酸钴（Cohcc）的方法包括钴沉积，然后在K ₃ [Co（CN）₆ ]水溶液中对金属Co进行电化学氧化。在模拟的阳光照射下，将改性电极作为光阳极进行水氧化测试。使用UV-Vis光谱，拉曼光谱和扫描电子显微镜对沉积的膜进行表征。自V ₂ O ₅具有比BiVO ₄窄的能带隙的特点，V ₂ O ₅的存在使改性膜的吸收边缘（ΔE=〜0.25 eV）向较低的能量移动，从而可以转换更宽的太阳辐射范围。异质结的形成将在1.2 V相对于Ag / AgCl（3 M KCl）的条件下测得的水氧化光电流增加至超过1 mA cm ^-2，而裸BiVO ₄和V ₂ O ₅表现出0.37和0.08 mA cm ^-2， 分别。另一方面，用Cohcc对获得的层的改性将光电流产生的起始电势转移到阴极方向上。结果，实现了在广泛的施加电势下的光电流增强。

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