Charge-Carrier Dynamics at the CuWO 4 /Electrocatalyst Interface for Photoelectrochemical Water Oxidation
Charge-Carrier Dynamics at the CuWO 4 /Electrocatalyst Interface for Photoelectrochemical Water Oxidation
复制标题
光电化学水氧化的 CuWO 4 /电催化剂界面的载流子动力学
DOI：
10.1021/acsami.0c14705
复制
发表时间：
2020
影响因子：
9.5
通讯作者：
Hamann, Thomas W.
中科院分区：
文献类型：
--
作者：
Shadabipour, Parisa;Raithel, Austin L.;Hamann, Thomas W.
揭示电催化剂/电极界面的电荷-载流子动力学对于发展高效的光电化学(PEC)水氧化是至关重要的。与大多数用于PEC水氧化的光阳极不同，电催化剂与CuWO4电极的集成通常导致与裸电极相比性能相当或更差。这是尽管表面状态复合限制了CuWO4电极的水氧化效率，而电催化剂应该绕过这一反应并提高性能。在这里，我们提供的结果加深了对CuWO4/电催化剂界面上的能量和电子转移过程的理解，这些过程控制着这类系统的性能。选择Ni0.75Fe0.25Oy(记为Ni75)作为模型电催化剂，通过双工作电极实验，对电催化剂在CuWO4/Ni75界面电荷转移过程中的作用进行了深入的研究。与裸电极相比，CuWO4/Ni75对水氧化的性能没有明显的提高。我们将这一令人惊讶的结果归因于CuWO4表面上的水氧化动力学地胜过了Ni75电催化剂界面上的空穴转移。
Unraveling the charge-carrier dynamics at electrocatalyst/electrode interfaces is critical for the development of efficient photoelectrochemical (PEC) water oxidation. Unlike the majority of photoanodes investigated for PEC water oxidation, the integration of electrocatalysts with CuWO4electrodes generally results in comparable or worse performance compared to the bare electrode. This is despite the fact that the surface state recombination limits the water oxidation efficiency with CuWO4electrodes, and an electrocatalyst ought to bypass this reaction and improve performance. Here, we present results that deepen the understanding of the energetics and electron-transfer processes at the CuWO4/electrocatalyst interface, which controls the performance of such systems. Ni0.75Fe0.25Oy(denoted as Ni75) was chosen as a model electrocatalyst, and through dual-working electrode experiments, we have been able to provide significant insight into the role of the electrocatalyst on the charge-transfer process at the CuWO4/Ni75 interface. We have shown a lack of performance improvement for CuWO4/Ni75 relative to the bare electrode to water oxidation. We attribute this surprising result to water oxidation on the CuWO4surface kinetically outcompeting hole transfer to the Ni75 electrocatalyst interface.