Copper vanadates are a promising class of solar fuel photoanodes with broad spectral response and excellent operational stability. The present performance limitations of these photoanodes are most evident in the rapid decrease in photoactivity with decrease in either photon energy or applied bias, the former limiting efficient utilization of the solar spectrum and the latter limiting photovoltage. We designed high-throughput photoelectrochemical screening to characterize these two aspects of improving Cu-V-based photoanodes in quaternary oxide composition spaces of the form Cu-V-X-O, where X = Mg, Ca, Sr, Fe. The results reveal that alloying of 2+ cations onto the Cu site of copper vanadates can improve photoelectrochemical properties, and Sr-alloyed Cu₅V₂O₁₀ emerges as the most promising photoanode providing the best combination of photovoltage and spectral response. Six quaternary oxide phases are discovered as photoanodes with visible light activity below 1.23 V versus reversible hydrogen electrode, highlighting the high-throughput photoanode discovery.

钒酸铜是一类有前途的太阳能燃料光阳极，具有宽光谱响应和出色的操作稳定性。这些光阳极的当前性能局限性最明显的表现是光活性迅速降低，同时光子能量或施加的偏压降低，前者限制了太阳光谱的有效利用，而后者限制了光电压。我们设计了高通量光电化学筛选，以表征这两个方面的特征，即改进以Cu-VXO形式存在的四元氧化物组成空间中基于Cu-V的光阳极，其中X = Mg，Ca，Sr，Fe。结果表明，将2+阳离子合金化到钒酸铜的Cu位上可以改善光电化学性能，以及Sr合金化的Cu ₅ V ₂ O ₁₀成为最有前途的光电阳极，可提供光电压和光谱响应的最佳组合。与可逆氢电极相比，发现了六个季铵氧化物相作为可见光活度低于1.23 V的光阳极，这突出了高通量光阳极的发现。