Self-Standing Hierarchical Porous Nickel-Iron Phosphide/Nickel Foam for Long-Term Overall Water Splitting
Self-Standing Hierarchical Porous Nickel-Iron Phosphide/Nickel Foam for Long-Term Overall Water Splitting
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DOI：
10.3390/catal13091242
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发表时间：
2023-08
期刊：
影响因子：
3.9
通讯作者：
Qixian Han;Hongmei Wu;Feng Li;Jing Liu;Liping Zhao;P. Zhang;Lian Gao
中科院分区：
文献类型：
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作者：
Qixian Han;Hongmei Wu;Feng Li;Jing Liu;Liping Zhao;P. Zhang;Lian Gao
与光伏、风电等绿色电力相结合，电解水分解是生产清洁氢气的一条有前景的途径；然而，大电流水电解主要依赖于Pt、Ru等昂贵材料的使用，而过渡金属基催化剂在电催化活性和稳定性方面仍需提高。在这里，我们介绍了经济且可扩展的电极材料——磷化镍铁/泡沫镍（NiFeP/NF）的制备方法，该材料具有分层多孔结构，可作为阳极和阴极进行整体水分解。通过使用 NiFeP/NF 作为阳极和阴极，电流密度为 100 mA cm−2 时的总电势为 1.85 V，并且使用寿命为 700 小时。研究了复合磷化物的纳米结构，并对长期电解后的废电极进行了表征，以研究磷化物的长期失效机制。针对NiFeP/NF阴极和阳极长期电解失效的情况，分别提出了表面脱落理论和重构理论。此外，TiO2涂层被证明是延长磷化物电极寿命的有效策略，其电流下降率为0.49 mA·cm−2 h−1。
Electrolytic water splitting is a promising path for the production of clean hydrogen when combined with green electric power, such as photovoltaic and wind power; however, the high current water electrolysis is mainly dependent on the utilization of Pt, Ru, and other expensive materials, while the transition metal-based catalysts still need improvement in electrocatalytic activity and stability. Here, we present the preparation of economic and scalable electrode materials, Nickel-Iron phosphide/Nickel foam (NiFeP/NF), with a hierarchical porous structure for overall water splitting as both the anode and cathode. An overall potential of 1.85 V for the current density of 100 mA cm−2, and a long lifetime of 700 h, were achieved by using NiFeP/NF as both the anode and cathode. The nanostructures of the composite phosphides were investigated and the spent electrode after long-term electrolysis was characterized to investigate the long-term failure mechanism of the phosphides. Surface shedding and reconstruction theories were proposed for the failure of the NiFeP/NF cathode and anode in long-term electrolysis, respectively. Furthermore, TiO2 coating was proved to be an efficient strategy to elongate the lifetime of the phosphide electrodes, which shows a slow current decline rate of 0.49 mA·cm−2 h−1.