Combinatorial (photo)electrochemical studies of the (Ni–Mn)O_x system reveal a range of promising materials for oxygen evolution photoanodes. X-ray diffraction, quantum efficiency, and optical spectroscopy mapping reveal stable photoactivity of NiMnO₃ in alkaline conditions with photocurrent onset commensurate with its 1.9 eV direct band gap. The photoactivity increases upon mixture with 10–60% Ni₆MnO₈ providing an example of enhanced charge separation via heterojunction formation in mixed-phase thin film photoelectrodes. Density functional theory-based hybrid functional calculations of the band edge energies in this oxide reveal that a somewhat smaller than typical fraction of exact exchange is required to explain the favorable valence band alignment for water oxidation.

中文翻译：

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碱性稳定的镍锰氧化物，具有理想的带隙，适用于太阳能燃料光阳极†

（Ni-Mn）O _x系统的组合（光）电化学研究揭示了用于氧气析出光阳极的一系列有前途的材料。X射线衍射，量子效率和光学光谱图揭示了碱性条件下NiMnO _3的稳定光活性，其光电流开始与其1.9 eV直接带隙相当。与10–60％Ni ₆ MnO ₈混合后，光活性会增加，这是通过以下方法增强电荷分离的一个例子混合相薄膜光电极中的异质结形成。基于氧化物的能带边能量的基于密度泛函理论的混合泛函计算表明，要解释水价氧化的有利价带取向，需要比实际交换的分数小一些的典型交换。