Abstract The establishment of multi-component catalytic systems on Fe2O3 photoanodes presents considerable potential for significantly enhancing the performance of photoelectrochemical water splitting systems. In this study, we hydrothermally synthesized a Fe2O3 photoanode. In addition, d-FeOOH synthesized via dip-coating and hydrothermally prepared h-FeOOH were used as cocatalysts and their synergistic combinations with cobalt phosphate (Co-Pi) were investigated. The synergy between h-FeOOH and Co-Pi was remarkable, whereas that between d-FeOOH and Co-Pi was negligible. For example, the onset potentials of the Co-Pi/h-FeOOH and Co-Pi/d-FeOOH dual catalysts, were cathodically shifted by 270 and 170 mV, respectively. Moreover, the photocurrent density of the Co-Pi/h-FeOOH/Fe2O3 anode was significantly higher than that of the Co-Pi/d-FeOOH/Fe2O3 one. The synergistic effect of Co-Pi and h-FeOOH could be attributed to the significantly inhibited recombination of surface charges owing to the formation of a p-n junction between β-FeOOH and Fe2O3 and the large contact area between the granular h-FeOOH and Co-Pi. However, the thin amorphous FeOOH layer of the Co-Pi/d-FeOOH/Fe2O3 anode acted as a hole-transfer medium, and weakly promoted the kinetics of the charge transfer process.

中文翻译：

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共载Co-Pi和FeOOH对Fe2O3光阳极协同作用用于光电化学水氧化的功能原理

摘要 在 Fe2O3 光阳极上建立多组分催化体系对于显着提高光电化学水分解系统的性能具有相当大的潜力。在这项研究中，我们水热合成了 Fe2O3 光阳极。此外，通过浸涂合成的 d-FeOOH 和水热制备的 h-FeOOH 用作助催化剂，并研究了它们与磷酸钴 (Co-Pi) 的协同组合。h-FeOOH 和 Co-Pi 之间的协同作用是显着的，而 d-FeOOH 和 Co-Pi 之间的协同作用可以忽略不计。例如，Co-Pi/h-FeOOH 和 Co-Pi/d-FeOOH 双催化剂的起始电位分别阴极偏移 270 和 170 mV。此外，Co-Pi/h-FeOOH/Fe2O3 阳极的光电流密度明显高于 Co-Pi/d-FeOOH/Fe2O3 阳极。Co-Pi 和 h-FeOOH 的协同效应可归因于 β-FeOOH 和 Fe2O3 之间形成 pn 结以及颗粒 h-FeOOH 和 Co-之间的大接触面积，从而显着抑制了表面电荷的复合。皮。然而，Co-Pi/d-FeOOH/Fe2O3 阳极的薄非晶 FeOOH 层充当了空穴传输介质，并微弱地促进了电荷传输过程的动力学。