Storing solar energy in chemical bonds is an effective strategy to overcome the intermittency of sunlight as an energy source. Here, we demonstrate unassisted light-driven electrochemical aqueous carbon dioxide reduction to carbon monoxide and methane using p-i-n double-cation lead halide perovskite solar cells in combination with catalytic electrodes for carbon dioxide reduction and water oxidation at near-neutral pH. Three series-connected photovoltaic cells and gold and ruthenium(IV) oxide electrodes provide carbon monoxide with >8% solar-to-carbon monoxide conversion efficiency for 4.5 h. Including concomitant hydrogen formation, the total solar-to-fuel conversion efficiency remains >8.3% for 10 h. Four series-connected cells with copper and ruthenium(IV) oxide electrodes provide methane. The longevity of the copper electrode improves by setting the cell to open circuit for 1 min every 15 min. The solar-to-methane conversion efficiency is close to 2%, and including 3% solar-to-hydrogen conversion efficiency, the solar-to-fuel conversion efficiency is 5% for 8 h.

以化学键存储太阳能是克服阳光作为能源的间歇性的有效策略。在这里，我们演示了使用销钉将无辅助光驱动的电化学含水二氧化碳还原为一氧化碳和甲烷双阳离子卤化钙钛矿型钙钛矿太阳能电池与催化电极结合使用，可在近中性pH值下减少二氧化碳和水氧化。三个串联连接的光伏电池以及氧化金和钌（IV）电极可在4.5小时内为一氧化碳提供大于8％的太阳能转化为一氧化碳的效率。包括伴随的氢形成，总的太阳能转化效率在10小时内保持> 8.3％。具有氧化铜和钌（IV）电极的四个串联电池可提供甲烷。每隔15分钟将电池设置为开路1分钟，可提高铜电极的寿命。太阳到甲烷的转换效率接近2％，包括3％的太阳到氢的转换效率，在8小时内太阳到燃料的转换效率是5％。