The significance of the local structure of cobalt-based catalysts on the photoelectrochemical water oxidation activity of BiVO4
The significance of the local structure of cobalt-based catalysts on the photoelectrochemical water oxidation activity of BiVO4
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DOI：
10.1016/j.electacta.2020.137467
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发表时间：
2021
影响因子：
6.6
通讯作者：
Mahsa Barzgar Vishlaghi;A. Kahraman;S. Apaydın;E. Usman;Dilan Aksoy;T. Balkan;Shamsa Munir;M. Harfouche;H. Ogasawara;S. Kaya
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文献类型：
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作者：
Mahsa Barzgar Vishlaghi;A. Kahraman;S. Apaydın;E. Usman;Dilan Aksoy;T. Balkan;Shamsa Munir;M. Harfouche;H. Ogasawara;S. Kaya
水氧化催化剂的局部结构对反应动力学和光阳极的性能起着重要的作用。在这项研究中，我们采用原子层沉积（ALD）的方法在厚度可控的纳米多孔bivo4上沉积钴基催化剂。尽管在所有沉积中钴的氧化态相似，但在中性pH条件下观察到不同的水氧化活性。当在BiVO4上形成均匀的超薄Co(OH)2层时，光电流显著增加，动力学过电位降低，光阳极/电解质界面上电荷转移电阻减小。当催化剂为Co(OH)2时，水氧化的光电流密度在0.6 V时比RHE提高95%，而CoO的光电流密度提高80%。Co(OH)2在羟基化bivo4表面上的理想配位有助于电解质和bivo4之间的电荷转移，而不会增加表面重组。本研究结果强调了控制催化剂局部结构对水分解光阳极性能的重要性。
The local structures of the water oxidation catalysts play an important role in reaction kinetics and the performance of the photoanodes. In this study, we deposited cobalt-based catalysts on nanoporous BiVO4with controlled thicknesses by atomic layer deposition (ALD). Despite the similar oxidation states of cobalt in all depositions, different water oxidation activities in neutral pH conditions were observed. A dramatic photocurrent raise, lowered kinetic overpotential, and smaller charge transfer resistance across the photoanode/electrolyte interface were achieved when a uniform ultrathin Co(OH)2layer was formed on BiVO4. Photocurrent density for water oxidation showed a 95% enhancement at 0.6 V vs. RHE when the catalyst was in the form of Co(OH)2, while an 80% increase was obtained for CoO. Ideal coordination of Co(OH)2on hydroxylated BiVO4surface assists the charge transfer between the electrolyte and BiVO4without increasing surface recombination. The results of this study emphasize the importance of controlling the local structure of the catalysts in the performance of the water splitting photoanodes.