Seawater splitting to produce hydrogen holds promise for renewable energy but faces challenges from chloride ions, causing electrode corrosion and competition between chlorine oxidation reaction (ClOR) and oxygen evolution reaction (OER). Therefore, it is crucial to develop highly efficient and stable electrocatalysts for seawater splitting. Here, we employ a dual-doping strategy of Mo/Cr cations and a sulfuration approach to fabricate the S-MoCr-NiFe@NF bifunctional catalyst with a 3D nano-flower structure. The S-MoCr-NiFe@NF catalyst exhibits remarkable catalytic performance for the oxygen evolution reaction (OER) in 1.0 M KOH + 0.5 M NaCl and 1.0 M KOH + Seawater, achieving current densities of 10 mA cm⁻² at low overpotentials of 116 and 141 mV, respectively. Furthermore, it was demonstrated that the S-MoCr-NiFe@NF catalyst exhibited remarkable performance in alkaline overall seawater splitting, requiring only 1.48 and 1.57 V to achieve current densities of 10 mA cm⁻² in 1.0 M KOH + 0.5 M NaCl and 1.0 M KOH + Seawater, respectively. The in-situ Raman and DFT calculations confirm Ni as the primary active sites, reducing the energy barrier of the rate-determining step and enhancing OER performance. This study will offer a viable approach to developing and creating highly effective bifunctional catalysts for seawater splitting.

中文翻译：

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通过 Mo/Cr 阳离子的双掺杂调制 NiFe 层状双氢氧化物中的氧空位，以实现高效的海水制氢


海水分解产生氢气为可再生能源带来了希望，但面临氯离子的挑战，导致电极腐蚀以及氯氧化反应 （ClOR） 和析氧反应 （OER） 之间的竞争。因此，开发高效稳定的海水分解电催化剂至关重要。在这里，我们采用 Mo/Cr 阳离子的双掺杂策略和硫化方法来制备具有 3D 纳米花结构的 S-MoCr-NiFe@NF 双功能催化剂。S-MoCr-NiFe@NF催化剂在 1.0 M KOH + 0.5 M NaCl 和 1.0 M KOH + 海水中表现出卓越的析氧反应 （OER） 催化性能，在 116 和 141 mV 的低过电位下分别实现了 10 mA ^cm-2 的电流密度。此外，结果表明，S-MoCr-NiFe@NF催化剂在碱性整体海水分解中表现出显着的性能，在 1.0 M KOH + 0.5 M NaCl 和 1.0 M KOH + 海水中，分别需要 1.48 和 1.57 V 即可实现 10 mA ^cm-2 的电流密度。原位拉曼和 DFT 计算确认 Ni 是主要活性位点，从而降低了速率确定步骤的能量势垒并提高了 OER 性能。本研究将为开发和创造用于海水分解的高效双功能催化剂提供一种可行的方法。