Bertram Manon, Waidhas Fabian, Jevric Martyn, Fromm Lukas, Schuschke Christian, Kastenmeier Maximilian, Görling Andreas, Moth-Poulsen Kasper, Brummel Olaf, Libuda Jörg
Interface Research and Catalysis, Erlangen Catalysis Resource Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany.
Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden.
J Chem Phys. 2020 Jan 31;152(4):044708. doi: 10.1063/1.5137897.
Employing molecular photoswitches, we can combine solar energy conversion, storage, and release in an extremely simple single molecule system. In order to release the stored energy as electricity, the photoswitch has to interact with a semiconducting electrode surface. In this work, we explore a solar-energy-storing model system, consisting of a molecular photoswitch anchored to an atomically defined oxide surface in a liquid electrolyte and under potential control. Previously, this model system has been proven to be operational under ultrahigh vacuum (UHV) conditions. We used the tailor-made norbornadiene derivative 2-cyano-3-(4-carboxyphenyl)norbornadiene (CNBD) and characterized its photochemical and electrochemical properties in an organic electrolyte. Next, we assembled a monolayer of CNBD on a well-ordered CoO(111) surface by physical vapor deposition in UHV. This model interface was then transferred into the liquid electrolyte and investigated by photoelectrochemical infrared reflection absorption spectroscopy experiments. We demonstrate that the anchored monolayer of CNBD can be converted photochemically to its energy-rich counterpart 2-cyano-3-(4-carboxyphenyl)quadricyclane (CQC) under potential control. However, the reconversion potential of anchored CQC overlaps with the oxidation and decomposition potential of CNBD, which limits the electrochemically triggered reconversion.
利用分子光开关，我们可以在一个极其简单的单分子系统中实现太阳能的转换、存储和释放。为了将存储的能量以电的形式释放出来，光开关必须与半导体电极表面相互作用。在这项工作中，我们探索了一种太阳能存储模型系统，该系统由一个分子光开关组成，该光开关在液体电解质中且在电位控制下锚定在原子级定义的氧化物表面。此前，已证明该模型系统在超高真空（UHV）条件下可运行。我们使用了特制的降冰片二烯衍生物2-氰基-3-（4-羧基苯基）降冰片二烯（CNBD），并在有机电解质中对其光化学和电化学性质进行了表征。接下来，我们在超高真空下通过物理气相沉积在有序的CoO(111)表面组装了一层CNBD单分子层。然后将这个模型界面转移到液体电解质中，并通过光电化学红外反射吸收光谱实验进行研究。我们证明，在电位控制下，锚定的CNBD单分子层可以光化学转化为其能量丰富的对应物2-氰基-3-（4-羧基苯基）四环烷（CQC）。然而，锚定的CQC的再转化电位与CNBD的氧化和分解电位重叠，这限制了电化学触发的再转化。
