Department of Energy Engineering, Hanyang University , Seoul 133-791, Korea.
The Research Institute of Industrial Science, Hanyang University , Seoul 133-791, Korea.
ACS Appl Mater Interfaces. 2017 Oct 4;9(39):33766-33774. doi: 10.1021/acsami.7b07984. Epub 2017 Sep 19.
The design of efficient, low-cost, and stable electrocatalyst systems toward energy conversion is highly demanding for their practical use. Large scale electrolytic water splitting is considered as a promising strategy for clean and sustainable energy production. Herein, we report a self-supported NiFe layered double hydroxide (LDH)-NiSe electrocatalyst by stepwise surface-redox-etching of Ni foam (NF) through a hydrothermal process. The as-prepared NiFe LDH-NiSe/NF catalyst exhibits far better performance in alkaline water oxidation, proton reduction, and overall water splitting compared to NiSe/NF or NiFe LDH/NF. Only 240 mV overpotential is required to obtain a water oxidation current density of 100 mA cm, whereas the same for the hydrogen evolution reaction is 276 mV in 1.0 M KOH. The synergistic effect from NiSe and NiFe LDH leads to the evolution of a highly efficient catalyst system for water splitting by achieving 10 mA cm current density at only 1.53 V in a two-electrode alkaline electrolyzer. In addition, the designed electrode produces stable performance for a long time even at higher current density to demonstrate its robustness and prospective as a real-life energy conversion system.
设计高效、低成本、稳定的电催化剂体系对于其实际应用至关重要。大规模水电解被认为是一种清洁和可持续能源生产的有前途的策略。在此，我们通过水热法在泡沫镍（NF）上进行分步表面氧化还原刻蚀，报告了一种自支撑的 NiFe 层状双氢氧化物（LDH）-NiSe 电催化剂。与 NiSe/NF 或 NiFe LDH/NF 相比，所制备的 NiFe LDH-NiSe/NF 催化剂在碱性水氧化、质子还原和整体水分解中表现出更好的性能。在 1.0 M KOH 中，获得 100 mA cm 的水氧化电流密度仅需要 240 mV 的过电势，而对于析氢反应则需要 276 mV。NiSe 和 NiFe LDH 的协同作用通过在两电极碱性电解槽中仅在 1.53 V 时达到 10 mA cm 的电流密度，从而实现了高效的水分解催化剂体系的发展。此外，所设计的电极即使在更高的电流密度下也能长时间稳定运行，展示了其作为实际能源转换系统的稳健性和前瞻性。
