Optically tunable windows based on reversible metal electrodeposition are an exciting alternative to static lighting control methods such as blinds and shades. In this Letter, we study reversible Bi/Cu electrodeposition on Pt-modified transparent conducting electrodes for electrochromic applications. Spectroelectrochemical measurements combined with scanning electron microscopy images indicate that the electrolytic Bi:Cu ratio drastically affects the electrode switching speed and electrodeposit morphology, which we propose is due to the galvanic displacement of Bi by Cu⁺. These findings allow us to construct 25 cm² black dynamic windows with reversibly tunable transmission at fast switching speeds. This rapid cycling can be maintained over 1000 cycles without degradation in contrast or uniformity. Finally, the Bi–Cu windows consume no power to maintain either their transparency or opacity, making them promising candidates for energy-efficient devices. Their combination of fast switching, color neutrality, durable cycling, and dual-state resting stability make dynamic windows based on Bi–Cu reversible electrodeposition promising and competitive alternatives to traditional electrochromic materials.

中文翻译：

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基于Bi和Cu的可逆金属电沉积的双稳态黑色电致变色窗。

基于可逆金属电沉积的光学可调窗是静态照明控制方法（如百叶窗和窗帘）的一种令人兴奋的替代方法。在这封信中，我们研究了用于电致变色应用的Pt改性透明导电电极上可逆的Bi / Cu电沉积。光谱电化学测量与扫描电子显微镜图像相结合表明，电解的Bi：Cu比率会极大地影响电极的切换速度和电沉积形态，我们提出这是由于Bi被Cu ⁺电化学置换所致。这些发现使我们能够构建25 cm ²黑色动态窗口，具有可逆可调的传输，且切换速度快。可以在1000个循环中保持这种快速循环，而不会降低对比度或均匀度。最后，Bi-Cu窗口不消耗任何功率来维持其透明性或不透明性，使其成为节能设备的有希望的候选者。快速开关，颜色中性，持久的循环以及双态静止稳定性的结合使基于Bi-Cu可逆电沉积的动态窗口成为传统电致变色材料的有希望且具有竞争力的替代方案。