Shadabipour Parisa, Raithel Austin L, Hamann Thomas W
Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824-1322, United States.
ACS Appl Mater Interfaces. 2020 Nov 11;12(45):50592-50599. doi: 10.1021/acsami.0c14705. Epub 2020 Oct 29.
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 CuWO electrodes 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 CuWO electrodes, 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 CuWO/electrocatalyst interface, which controls the performance of such systems. NiFeO (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 CuWO/Ni75 interface. We have shown a lack of performance improvement for CuWO/Ni75 relative to the bare electrode to water oxidation. We attribute this surprising result to water oxidation on the CuWO surface kinetically outcompeting hole transfer to the Ni75 electrocatalyst interface.
解析电催化剂/电极界面处的电荷载流子动力学对于高效光电化学（PEC）水氧化的发展至关重要。与大多数用于PEC水氧化研究的光阳极不同，电催化剂与CuWO电极集成后，其性能通常与裸电极相比相当或更差。尽管表面态复合限制了CuWO电极的水氧化效率，并且电催化剂应该绕过该反应并提高性能，但情况依然如此。在此，我们展示的结果加深了对CuWO/电催化剂界面处的能量学和电子转移过程的理解，该界面控制着此类系统的性能。选择NiFeO（表示为Ni75）作为模型电催化剂，通过双工作电极实验，我们得以深入了解电催化剂在CuWO/Ni75界面处电荷转移过程中的作用。我们已经表明，相对于裸电极，CuWO/Ni75在水氧化方面缺乏性能提升。我们将这一惊人结果归因于CuWO表面的水氧化在动力学上胜过空穴向Ni75电催化剂界面的转移。
