De Ratnadip, Hermesdorf Marius, Bera Anupam, Phul Ruby, Gawlik Annett, Plentz Jonathan, Oschatz Martin, Karadaş Ferdi, Dietzek-Ivanšić Benjamin
Department of Functional Interfaces, Leibniz Institute of Photonic Technology, Albert-Einstein-Strasse 9, 07745, Jena, Germany.
Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.
Chemistry. 2024 Oct 28;30(60):e202401708. doi: 10.1002/chem.202401708. Epub 2024 Oct 16.
Understanding the interfacial composition in heterostructures is crucial for tailoring heterogenous electrochemical and photoelectrochemical processes. This work aims to elucidate the structure of a series of Co-Fe Prussian blue analogue modified ZnO (PBA/ZnO) electrodes with interface-sensitive vibrational sum frequency generation (VSFG) spectroscopy. Our measurements revealed, for the first time, a cyanide linkage isomerism at the PBA/ZnO interface, when the composite is fabricated at elevated temperatures. In situ VSFG spectro-electrochemistry measurements correlate the Co→Co oxidation with the flip of the bridging CN ligand from Co-NC-Fe coordination mode to a Co-CN-Fe one. Photoluminescence measurements and X-ray photoelectron spectroscopy reveal that this unprecedented linkage isomerism originates from surface defects, which act as oxidation sites for the PBA. The presence of such surface defects is correlated with the fabrication temperature for PBA/ZnO. Thus, this contribution identifies the interplay between the surface states of the ZnO substrates and the chemical composition of PBA at the ZnO surface, suggesting an easily accessible approach to control the chemical composition of the interface.
了解异质结构中的界面组成对于定制异质电化学和光电化学过程至关重要。这项工作旨在通过界面敏感的振动和频产生（VSFG）光谱来阐明一系列钴铁普鲁士蓝类似物修饰的氧化锌（PBA/ZnO）电极的结构。我们的测量首次揭示，当复合材料在高温下制备时PBA/ZnO界面处存在氰化物键合异构现象。原位VSFG光谱电化学测量将Co→Co氧化与桥连CN配体从Co-NC-Fe配位模式转变为Co-CN-Fe配位模式相关联。光致发光测量和X射线光电子能谱表明，这种前所未有的键合异构现象源于表面缺陷，这些表面缺陷充当了PBA的氧化位点。这种表面缺陷的存在与PBA/ZnO的制备温度相关。因此，本研究确定了ZnO基底的表面状态与ZnO表面PBA的化学成分之间的相互作用，提出了一种易于实现的控制界面化学成分的方法。
