This study conducts a comprehensive exploration of the synthesis and photoelectrochemical performance of delafossite AgFeO₂ nanosheets modulated by controlled hydrothermal conditions. The dimensions of the nanosheets, namely width and exposed area, are adjusted to examine the impact of surface polarization on photocatalytic efficiency. Notably, an increase in nanosheet width while keeping the thickness constant corresponds to a significant rise in photocurrent density. Under optimized conditions, AgFeO₂ nanosheets with smaller thickness and larger surface area of the (001) facet reach a peak photocurrent density of 15.6 μA cm⁻². This enhancement is attributed to the increased intensity and contribution of the built-in electric field on the (001) polar facet, thereby facilitating improved effective separation and rapid transfer of photogenerated electron–hole pairs. In brief, regarding the surface polarization effect of AgFeO₂ nanosheets, a smaller thickness leads to a stronger built-in electric field intensity generated by the surface polarization effect, while a larger exposed area makes a more significant contribution to the surface polarization effect. Therefore, to fully utilize the surface polarization effect, it is essential to carefully and precisely control the morphology and size of AgFeO₂ nanosheets during the preparation process. Moreover, the introduction of interstitial oxygen and an external magnetic field further demonstrates the potential of multiple polarization coupling—spin, macro, and surface—to maximize the photoelectrochemical potential of AgFeO₂ nanosheets. These findings emphasize the crucial role of surface polarization in optimizing the photoelectrochemical performance of AgFeO₂ nanosheets and highlight the potential of nanoscale design in developing advanced photocathodes. The findings open up avenues for future research aimed at refining synthesis methods and exploiting the synergistic effects of multiple polarizations for enhanced solar energy conversion efficiencies.

中文翻译：

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解开水热衍生的 AgFeO2 纳米片中的表面极化以增强光电化学性能


本研究对受控水热条件下 delafossite AgFeO₂ 纳米片的合成和光电化学性能进行了全面探索。调整纳米片的尺寸，即宽度和暴露面积，以检查表面极化对光催化效率的影响。值得注意的是，在保持厚度不变的情况下，纳米片宽度的增加对应于光电流密度的显着增加。在优化条件下，（001） 刻面厚度较小且表面积较大的 AgFeO₂ 纳米片达到 15.6 μA ^cm-2 的峰值光电流密度。这种增强归因于 （001） 极面上内置电场的强度和贡献增加，从而促进了光生电子-空穴对的有效分离和快速转移。简而言之，关于 AgFeO₂ 纳米片的表面极化效应，较小的厚度导致表面极化效应产生的更强的内置电场强度，而较大的暴露面积对表面极化效应的贡献更显着。因此，为了充分利用表面极化效应，在制备过程中必须仔细、精确地控制 AgFeO₂ 纳米片的形貌和尺寸。此外，间隙氧和外部磁场的引入进一步证明了多极化耦合（自旋、宏和表面）的潜力，以最大限度地提高 AgFeO₂ 纳米片的光电化学电位。 这些发现强调了表面极化在优化 AgFeO₂ 纳米片的光电化学性能中的关键作用，并强调了纳米级设计在开发先进光阴极面方面的潜力。这些发现为未来的研究开辟了道路，旨在改进合成方法并利用多重极化的协同效应来提高太阳能转换效率。